User:Marskell/WikiLeads

Acrocanthosaurus
Acrocanthosaurus (, meaning 'high-spined lizard') is a genus of theropod dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. Its fossil remains are found mainly in the U.S. states of Oklahoma and Texas, although teeth attributed to Acrocanthosaurus have been found as far east as Maryland.

Acrocanthosaurus was a bipedal predator. As the name suggests, it is best known for the high neural spines on many of its vertebrae, which most likely supported a ridge of muscle over the animal's neck, back and hips. Acrocanthosaurus was one of the largest theropods, approaching 12 meters (40 ft) in length, and weighing up to 6.17 metric tons (6.8 short tons). Large theropod footprints discovered in Texas may have been made by Acrocanthosaurus, although there is no direct association with skeletal remains.

Recent discoveries have elucidated many details of its anatomy, allowing for specialized studies focusing on its brain structure and forelimb function. Acrocanthosaurus was the largest theropod in its ecosystem and likely an apex predator which possibly preyed on large sauropods and ornithopods.

Ailanthus altissima
Ailanthus altissima, commonly known as tree of heaven, ailanthus, or in Standard Mandarin as chouchun , is a deciduous tree in the Simaroubaceae family. It is native to both northeast and central China and Taiwan. Unlike other members of the genus Ailanthus, it is found in temperate climates rather than the tropics. The tree grows rapidly and is capable of reaching heights of 15 m in 25 years. However, the species is also short lived and rarely lives more than 50 years.

In China, the tree of heaven has a long and rich history. It was mentioned in the oldest extant Chinese dictionary and listed in countless Chinese medical texts for its purported ability to cure ailments ranging from mental illness to baldness. The roots, leaves and bark are still used today in traditional Chinese medicine, primarily as an astringent. The tree has been grown extensively both in China and abroad as a host plant for the ailanthus silkmoth, a moth involved in silk production. Ailanthus has become a part of western culture as well, with the tree serving as the central metaphor and subject matter of the best-selling American novel A Tree Grows in Brooklyn by Betty Smith.

The tree was first brought from China to Europe in the 1740s and to the United States in 1784. It was one of the first trees brought west during a time when chinoiserie was dominating European arts, and was initially hailed as a beautiful garden specimen. However, enthusiasm soon waned after gardeners became familiar with its suckering habits and its foul smelling odour. Despite this, it was used extensively as a street tree during much of the 19th century. Outside of Europe and the United States, the plant has been spread to many other areas beyond its native range. In a number of these, it has become an invasive species due to its ability to quickly colonise disturbed areas and suppress competition with allelopathic chemicals. It is considered a noxious weed in Australia, the United States, New Zealand and several countries in southern and eastern Europe. The tree also resprouts vigorously when cut, making its eradication difficult and time consuming. In many urban areas, it has acquired the derisive nicknames of "ghetto palm" and "stink tree".

Aiphanes
Aiphanes is a genus of spiny palms which is native to tropical regions of South and Central America and the Caribbean. There are about 26 species in the genus, ranging in size from understorey shrubs with subterranean stems to subcanopy trees as much as 20 m tall. Most have pinnately compound leaves (leaves which are divided into leaflets arranged feather-like, in pairs along a central axis); one species has entire leaves. Stems, leaves and sometimes even the fruit are covered with spines. Plants flower repeatedly over the course of their lifespan and have separate male and female flowers, although these are borne together on the same inflorescence. Although records of pollinators are limited, most species appear to be pollinated by insects. The fruit are eaten by several birds and mammals, including at least two species of Amazon parrots.

Carl Ludwig Willdenow coined the name Aiphanes in 1801. Before that, species belonging to the genus had been placed in Bactris or Caryota. The name Martinezia had also been applied to the genus, and between 1847 and 1932 it was generally used in place of Aiphanes. Max Burret resurrected the name Aiphanes in 1932, and laid the basis for the modern concept of the genus. Aiphanes is most closely related to several other genera of spiny palms—Acrocomia, Astrocaryum, Bactris and Desmoncus. Two species are widely planted as ornamentals and the fruit, seeds or palm heart of several species have been eaten by indigenous peoples of the Americas for centuries.

Albatrosses
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains show they once occurred there too and occasional vagrants turn up.

Albatrosses are among the largest of flying birds, and the great albatrosses (genus Diomedea) have the largest wingspans of any extant birds. The albatrosses are usually regarded as falling into four genera, but there is disagreement over the number of species.

Albatrosses are highly efficient in the air, using dynamic soaring and slope soaring to cover great distances with little exertion. They feed on squid, fish and krill by either scavenging, surface seizing or diving. Albatrosses are colonial, nesting for the most part on remote oceanic islands, often with several species nesting together. Pair bonds between males and females form over several years, with the use of 'ritualised dances', and will last for the life of the pair. A breeding season can take over a year from laying to fledging, with a single egg laid in each breeding attempt.

Of the 21 species of albatrosses recognised by the IUCN, 19 are threatened with extinction. Numbers of albatrosses have declined in the past due to harvesting for feathers, but today the albatrosses are threatened by introduced species such as rats and feral cats that attack eggs, chicks and nesting adults; by pollution; by a serious decline in fish stocks in many regions largely due to overfishing; and by long-line fishing. Long-line fisheries pose the greatest threat, as feeding birds are attracted to the bait, become hooked on the lines, and drown. Identified stakeholders such as governments, conservation organisations and people in the fishing industry are all working toward reducing this bycatch.

Albertosaurus
Albertosaurus (meaning "Alberta lizard") is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, more than 70 million years ago. The type species, A. sarcophagus, was restricted in range to the modern-day Canadian province of Alberta, after which the genus is named. Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species.

As a tyrannosaurid, Albertosaurus was a bipedal predator with tiny, two-fingered hands and a massive head with dozens of large, sharp teeth. It may have been at the top of the food chain in its local ecosystem. Although relatively large for a theropod, Albertosaurus was much smaller than its more famous relative Tyrannosaurus, probably weighing less than 2 metric tons.

Since the first discovery in 1884, fossils of more than thirty individuals have been recovered, providing scientists with a more detailed knowledge of Albertosaurus anatomy than is available for most other tyrannosaurids. The discovery of 22 individuals at one site provides evidence of pack behavior and allows studies of ontogeny and population biology which are impossible with lesser-known dinosaurs.

Allosaurus
Allosaurus is a genus of large theropod dinosaur that lived 155 to 145 million years ago, in the late Jurassic period (Kimmeridgian to Tithonian). The name Allosaurus means "different lizard" and is derived from the Greek αλλος/allos ("different, strange") and σαυρος/sauros ("lizard"). The first remains that can definitely be ascribed to this genus were described in 1877 by Othniel Charles Marsh. As one of the first well-known theropod dinosaurs, it has long attracted attention outside of paleontological circles, and has been a lead dinosaur in several films and documentaries.

Allosaurus was a large bipedal predator with a large skull, equipped with dozens of large, sharp teeth. It averaged 8.5 meters (28 ft) in length, though fragmentary remains suggest it could have reached over 12 meters (39 ft). Relative to the large and powerful hindlimbs, its three-fingered forelimbs were small, and the body was balanced by a long, heavy tail. It is classified as an allosaurid, a type of carnosaurian theropod dinosaur. The genus has a complicated taxonomy, and includes an uncertain number of valid species, the best known of which is A. fragilis. The bulk of Allosaurus remains have come from North America's Morrison Formation, with material also known from Portugal and possibly Tanzania. It was known for over half of the 20th century as Antrodemus, but study of the copious remains from the Cleveland Lloyd Dinosaur Quarry brought the name Allosaurus back to prominence, and established it as one of the best-known dinosaurs.

As the prominent large predator in the Morrison Formation, Allosaurus was at the top of the food chain, probably preying on contemporaneous large herbivorous dinosaurs and perhaps even other predators (e.g. Ceratosaurus). Potential prey included ornithopods, stegosaurids, and sauropods. Some paleontologists interpret Allosaurus as having had cooperative social behavior, and hunting in packs, while others believe individuals may have been aggressive toward each other, and that congregations of this genus are the result of lone individuals feeding on the same carcasses. It may have attacked large prey by ambush, using its upper jaws like a hatchet.

Alpine Chough
The Alpine Chough, or Yellow-billed Chough, (Pyrrhocorax graculus) is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its two subspecies breed in high mountains from Spain east through southern Europe and North Africa to Central Asia, India and China, and it may nest at a higher altitude than any other bird. The eggs have adaptations to the thin atmosphere that improve oxygen take-up and reduce water loss.

This bird has glossy black plumage, a yellow bill, red legs, and distinctive calls. It has a buoyant acrobatic flight with widely spread flight feathers. The Alpine Chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It builds a lined stick nest and lays three to five brown-blotched whitish eggs. It feeds, usually in flocks, on short grazed grassland, taking mainly invertebrate prey in summer and fruit in winter; it will readily approach tourist sites to find supplementary food.

Although it is subject to predation and parasitism, and changes in agricultural practices have caused local population declines, this widespread and abundant species is not threatened globally. Climate change may present a long-term threat, by shifting the necessary alpine habitat to higher altitudes.

Amanita bisporigera
Amanita bisporigera is a deadly poisonous species of fungus in the Amanitaceae family. It is commonly known as the eastern North American destroying angel or the destroying angel, although it shares this latter name with three other lethal white Amanita species, A. ocreata, A. verna and A. virosa. The fruit bodies are found on the ground in mixed coniferous and deciduous forests of Eastern North America south to Mexico, but are rare in western North America; it has also been found in pine plantations in Colombia. The mushroom has a smooth white cap that can reach up to 10 cm across, and a stem, up to 14 cm by 1.8 cm thick, that has a delicate white skirt-like ring near the top. The bulbous stem base is covered with a membranous sac-like volva. The white gills are free from attachment to the stalk and crowded closely together. As the species name suggests, A. bisporigera typically bears two spores on the basidia, although this characteristic is not as immutable as was once thought.

First described in 1906, A. bisporigera is classified in the section Phalloideae of the genus Amanita together with other amatoxin-containing species. Amatoxins are cyclic peptides which inhibit the enzyme RNA polymerase II and interfere with various cellular functions. The first symptoms of poisoning appear 6 to 24 hours after consumption, followed by a period of apparent improvement, then by symptoms of liver and kidney failure, and death after four days or more. Amanita bisporigera closely resembles a few other white amanitas, including the equally deadly A. virosa and A. verna. These species, difficult to distinguish from A. bisporigera based on visible field characteristics, do not have two-spored basidia, and do not stain yellow when a dilute solution of potassium hydroxide is applied. The DNA of A. bisporigera has been partially sequenced, and the genes responsible for the production of amatoxins have been determined.

Amanita ocreata
Amanita ocreata, commonly known as the death angel, destroying angel or more precisely Western North American destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in the Pacific Northwest and California floristic provinces of North America, A. ocreata associates with oak trees. The large fruiting bodies (the mushrooms) generally appear in spring; the cap may be white or ochre and often develops a brownish centre, while the stipe, ring, gill and volva are all white.

Amanita ocreata resemble several edible species commonly consumed by humans, increasing the risk of accidental poisoning. Mature fruiting bodies can be confused with the edible A. velosa, A. lanei or Volvariella speciosa, while immature specimens may be difficult to distinguish from edible Agaricus mushrooms or puffballs. Similar in toxicity to the death cap (A. phalloides) and destroying angels of Europe (A. virosa) and eastern North America (A. bisporigera), it is a potentially deadly fungus responsible for a number of poisonings in California. Its principal toxic constituent, α-amanitin, damages the liver and kidneys, often fatally, and has no known antidote. The initial symptoms are gastrointestinal and include  colicky abdominal pain, diarrhea and vomiting. These subside temporarily after 2–3 days, though ongoing damage to internal organs during this time is common; symptoms of jaundice, diarrhea, delirium, seizures, and coma may follow with death from liver failure 6–16 days post ingestion.

Amanita muscaria
Amanita muscaria, commonly known as the fly agaric or fly Amanita, is a poisonous and psychoactive basidiomycete fungus, one of many in the genus Amanita. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees. The quintessential toadstool, it is a large white-gilled, white-spotted, usually deep red mushroom, one of the most recognizable and widely encountered in popular culture. Several subspecies, with differing cap colour have been recognised to date, including the brown regalis (considered a separate species), the yellow-orange flavivolata, guessowii, and formosa, and the pinkish persicina. Genetic studies published in 2006 and 2008 show several sharply delineated clades which may represent separate species.

Although generally considered poisonous, deaths are extremely rare, and it has been consumed as a food in parts of Europe, Asia, and North America after parboiling in water. Amanita muscaria is now primarily famed for its hallucinogenic properties, with its main psychoactive constituent being the compound muscimol. It was used as an intoxicant and entheogen by the peoples of Siberia and has a religious significance in these cultures. There has been much speculation on traditional use of this mushroom as an intoxicant in places other than Siberia; however, such traditions are far less well-documented. The American banker and amateur ethnomycologist R. Gordon Wasson proposed the fly agaric was in fact the Soma talked about in the ancient Rig Veda texts of India; since its introduction in 1968, this theory has gained both detractors and followers in the anthropological literature.

Amanita phalloides
Amanita phalloides (generally ), commonly known as the death cap, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Widely distributed across Europe, A. phalloides associates with various broadleaved trees. In some cases, death cap has been accidentally introduced to new regions with the cultivation of non-native species of oak, chestnut, and pine. The large fruiting bodies (i.e., the mushrooms) appear in summer and autumn; the caps are generally greenish in color, with a white stipe and gills.

Coincidentally, these toxic mushrooms resemble several edible species (most notably the caesar's mushroom and the straw mushroom) commonly consumed by humans, increasing the risk of accidental poisoning. A. phalloides is one of the most poisonous of all known toadstools. It has been involved in the majority of human deaths from mushroom poisoning, possibly including the deaths of Roman Emperor Claudius and Holy Roman Emperor Charles VI. It has been the subject of much research, and many of its biologically active agents have been isolated. The principal toxic constituent is α-amanitin, which damages the liver and kidneys, often fatally.

American Goldfinch
The American Goldfinch (Spinus tristis), also known as the Eastern Goldfinch and Wild Canary, is a North American bird in the finch family. It is migratory, ranging from southern Canada to North Carolina during the breeding season, and from just south of the Canadian border to Mexico during the winter.

The only finch in its subfamily which undergoes a complete molt, the American Goldfinch displays sexual dimorphism in its coloration; the male is a vibrant yellow in the summer and an olive color during the winter months, while the female is a dull yellow-brown shade which brightens only slightly during the summer. The male displays brightly colored plumage during the breeding season to attract a mate.

The American Goldfinch is a granivore and adapted for the consumption of seedheads, with a conical beak to remove the seeds and agile feet to grip the stems of seedheads while feeding. It is a social bird, and will gather in large flocks while feeding and migrating. It may behave territorially during nest construction, but this aggression is short-lived. Its breeding season is tied to the peak of food supply, beginning in late July, which is relatively late in the year for a finch. This species is generally monogamous, and produces one brood each year.

Human activity has generally benefited the American Goldfinch. It is often found in residential areas, attracted to bird feeders installed by humans, which increases its survival rate in these areas. Deforestation by humans also creates open meadow areas which are the preferred habitat of the American Goldfinch.

Andean Condor
The Andean Condor (Vultur gryphus) is a species of South American bird in the New World vulture family Cathartidae and is the only member of the genus Vultur. Found in the Andes mountains and adjacent Pacific coasts of western South America, it has the largest wing span (at 3.2 m) of any land bird.

It is a large black vulture with a ruff of white feathers surrounding the base of the neck and, especially in the male, large white patches on the wings. The head and neck are nearly featherless, and are a dull red color, which may flush and therefore change color in response to the bird's emotional state. In the male, there is a wattle on the neck and a large, dark red comb or caruncle on the crown of the head. Unlike most birds of prey, the male is larger than the female.

The condor is primarily a scavenger, feeding on carrion. It prefers large carcasses, such as those of deer or cattle. It reaches sexual maturity at five or six years of age and nests at elevations of up to 5000 m, generally on inaccessible rock ledges. One or two eggs are usually laid. It is one of the world's longest-living birds, with a lifespan of up to 50 years.

The Andean Condor is a national symbol of Peru, Argentina, Bolivia, Chile, Colombia, and Ecuador, and plays an important role in the folklore and mythology of the Andean regions. The Andean Condor is considered near threatened by the IUCN. It is threatened by habitat loss and by secondary poisoning from carcasses killed by hunters. Captive breeding programs have been instituted in several countries.

American Goldfinch
The American Goldfinch (Spinus tristis), also known as the Eastern Goldfinch and Wild Canary, is a North American bird in the finch family. It is migratory, ranging from southern Canada to North Carolina during the breeding season, and from just south of the Canadian border to Mexico during the winter.

The only finch in its subfamily which undergoes a complete molt, the American Goldfinch displays sexual dimorphism in its coloration; the male is a vibrant yellow in the summer and an olive color during the winter months, while the female is a dull yellow-brown shade which brightens only slightly during the summer. The male displays brightly colored plumage during the breeding season to attract a mate.

The American Goldfinch is a granivore and adapted for the consumption of seedheads, with a conical beak to remove the seeds and agile feet to grip the stems of seedheads while feeding. It is a social bird, and will gather in large flocks while feeding and migrating. It may behave territorially during nest construction, but this aggression is short-lived. Its breeding season is tied to the peak of food supply, beginning in late July, which is relatively late in the year for a finch. This species is generally monogamous, and produces one brood each year.

Human activity has generally benefited the American Goldfinch. It is often found in residential areas, attracted to bird feeders installed by humans, which increases its survival rate in these areas. Deforestation by humans also creates open meadow areas which are the preferred habitat of the American Goldfinch.

Ants
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than 12,500 out of an estimated total of 22,000 species have been classified. They are easily identified by their elbowed antennae and a distinctive node-like structure that forms a slender waist.

Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies which may occupy large territories and consist of millions of individuals. These larger colonies consist mostly of sterile wingless females forming castes of "workers", "soldiers", or other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called "queens". The colonies are sometimes described as superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.

Ants have colonised almost every landmass on Earth. The only places lacking indigenous ants are Antarctica and a few remote or inhospitable islands. Ants thrive in most ecosystems, and may form 15–25% of the terrestrial animal biomass. Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic, commensal, parasitic, and mutualistic relationships.

Ant societies have division of labour, communication between individuals, and an ability to solve complex problems. These parallels with human societies have long been an inspiration and subject of study.

Many human cultures make use of ants in cuisine, medication and rituals. Some species are valued in their role as biological pest control agents. However, their ability to exploit resources brings ants into conflict with humans, as they can damage crops and invade buildings. Some species, such as the red imported fire ant, are regarded as invasive species in places where they have established themselves in areas where they have been accidentally introduced.

Antbirds
The antbirds are a large family, Thamnophilidae, of passerine birds found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 200 species, known variously as antshrikes, antwrens, antvireos, fire-eyes, bare-eyes and bushbirds. They are related to the antthrushes and antpittas (family Formicariidae), the tapaculos, the gnateaters and the ovenbirds.

Antbirds are generally small birds with rounded wings and strong legs. They have mostly sombre grey, white, brown and rufous plumage, which is sexually dimorphic in pattern and colouring. Some species communicate warnings to rivals by exposing white feather patches on their backs or shoulders. Most have heavy bills, which in many species are hooked at the tip.

Most species live in forests, although a few are found in other habitats. Insects and other arthropods form the most important part of their diet, although small vertebrates are occasionally taken. Most species feed in the understory and midstory of the forest, although a few feed in the canopy and a few on the ground. Many join mixed-species feeding flocks, and a few species are core members. To various degrees, around eighteen species specialise in following columns of army ants to eat the small invertebrates flushed by the ants, and many others may feed in this way opportunistically.

Antbirds are monogamous, mate for life and defend territories. They usually lay two eggs in a nest that is either suspended from branches or supported on a branch, stump or mound on the ground. Both parents share the tasks of incubation and of brooding and feeding the nestlings. After fledging, each parent cares exclusively for one chick.

Thirty-eight species are threatened with extinction due to human activities. Antbirds are not targeted by either hunters or the pet trade. The principal threat is habitat loss, which causes habitat fragmentation and increased nest predation in habitat fragments.

Archaea
The Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon (sometimes spelled "archeon"). They have no cell nucleus or any other organelles within their cells. In the past they were viewed as an unusual group of bacteria and named archaebacteria but since the Archaea have an independent evolutionary history and show many differences in their biochemistry from other forms of life, they are now classified as a separate domain in the three-domain system. In this system the phylogenetically distinct branches of evolutionary descent are the Archaea, Bacteria and Eukarya. Archaea are further divided into four recognized phyla, but many more phyla may exist. Of these groups the Crenarchaeota and the Euryarchaeota are most intensively studied. Classification is still difficult, since the vast majority have never been studied in the laboratory and have only been detected by analysis of their nucleic acids in samples from the environment. Although archaea have, in the past, been classed with bacteria as prokaryotes (or Kingdom Monera), this classification is outdated.

Archaea and bacteria are quite similar in size and shape, although a few archaea have very unusual shapes, such as the flat and square-shaped cells of Haloquadra walsbyi. Despite this visual similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes: notably the enzymes involved in transcription and translation. Other aspects of archaean biochemistry are unique, such as their reliance on ether lipids in their cell membranes. The archaea exploit a much greater variety of sources of energy than eukaryotes: ranging from familiar organic compounds such as sugars, to using ammonia, metal ions or even hydrogen gas as nutrients. Salt-tolerant archaea (the Halobacteria) use sunlight as an energy source and other species of archaea fix carbon; however, unlike plants and cyanobacteria, no species of archaea is known to do both. Archaea reproduce asexually and divide by binary fission, fragmentation, or budding; in contrast to bacteria and eukaryotes, no known species form spores.

Initially, archaea were seen as extremophiles that lived in harsh environments, such as hot springs and salt lakes, but they have since been found in a broad range of habitats, including soils, oceans, and marshlands. Archaea are particularly numerous in the oceans, and the archaea in plankton may be one of the most abundant groups of organisms on the planet. Archaea are now recognized as a major part of Earth's life and may play roles in both the carbon cycle and nitrogen cycle. No clear examples of archaeal pathogens or parasites are known, but they are often mutualists or commensals. One example are the methanogens that inhabit the gut of humans and ruminants, where their vast numbers aid digestion. Methanogens are used in biogas production and sewage treatment, and enzymes from extremophile archaea that can endure high temperatures and organic solvents are exploited in biotechnology.

Archaeopteryx
Archaeopteryx, sometimes referred to by its German name Urvogel ("original bird" or "first bird"), is the earliest and most primitive bird known. The name derives from the Ancient Greek ἀρχαῖος (archaīos) meaning "ancient", and πτέρυξ (ptéryx), meaning "wing".

Archaeopteryx lived during the Late Jurassic Period around 150–148 million years ago, in what is now southern Germany during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now.

Similar in size and shape to a European Magpie, Archaeopteryx could grow to about 0.5 metres (1.6 ft) in length. Despite its small size, broad wings, and inferred ability to fly or glide, Archaeopteryx has more in common with small theropod dinosaurs than it does with modern birds. In particular, it shares the following features with the deinonychosaurs (dromaeosaurs and troodontids): jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes ("killing claw"), feathers (which also suggest homeothermy), and various skeletal features. The features above make Archaeopteryx a clear candidate for a transitional fossil between dinosaurs and birds. Thus, Archaeopteryx plays an important role not only in the study of the origin of birds but in the study of dinosaurs. The first complete specimen of Archaeopteryx was announced in 1861, only two years after Charles Darwin published On the Origin of Species, and it became a key piece of evidence in the debate over evolution. Over the years, nine more fossils of Archaeopteryx have surfaced. Despite variation among these fossils, most experts regard all the remains that have been discovered as belonging to a single species, though this is still debated.

Many of these eleven fossils include impressions of feathers—among the oldest direct evidence of feathers. Moreover, because these feathers are an advanced form (flight feathers), these fossils are evidence that the evolution of feathers began before the Late Jurassic.

Arctic Tern
The Arctic Tern (Sterna paradisaea) is a seabird of the tern family Sternidae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe, Asia, and North America (as far south as Brittany and Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates from its northern breeding grounds along a winding route to the oceans around Antarctica and back, a round trip of about 70,900 km (c. 44,300 miles) each year. This is by far the longest regular migration by any known animal. The Arctic Tern flies as well as glides through the air, performing almost all of its tasks in the air. It nests once every one to three years (depending on its mating cycle); once it has finished nesting it takes to the sky for another long southern migration.

Arctic Terns are medium-sized birds. They have a length of 33–39 cm (13–15 in) and a wingspan of 76–85 cm (26–30 in). They are mainly grey and white plumaged, with a red beak (as long as the head, straight, with pronounced gonys) and feet, white forehead, a black nape and crown (streaked white), and white cheeks. The grey mantle is 305 mm, and the scapulars are fringed brown, some tipped white. The upper wing is grey with a white leading edge, and the collar is completely white, as is the rump. The deeply forked tail is whitish, with grey outer webs. The hindcrown to the ear-coverts is black.

Arctic Terns are long-lived birds, with many reaching thirty years of age. They eat mainly fish and small marine invertebrates. The species is abundant, with an estimated one million individuals. While the trend in the number of individuals in the species as a whole is not known, exploitation in the past has reduced this bird's numbers in the southern reaches of its range.

Armillaria gallica
Armillaria gallica (synonymous with A. bulbosa and A. lutea) is a species of honey mushroom in the Physalacriaceae family of the Agaricales order. The species is a common and ecologically important wood-decay fungus that can live as a saprobe, or as an opportunistic parasite in weakened tree hosts to cause root or butt rot. It has a widespread distribution, being found in temperate regions of Asia, North America, and Europe, and forms fruit bodies singly or in groups in soil or rotting wood. The fungus has been inadvertently introduced to South Africa. Armillaria gallica has had a confusing taxonomy, due in part to historical difficulties encountered in distinguishing between similar Armillaria species. The fungus received international attention in the early 1990s when an individual colony living in a Michigan forest was reported to cover an area of 15 ha, weigh at least 9500 kg, and be 1,500 years old. This individual is popularly known as the "humungous fungus", and is a tourist attraction and inspiration for an annual mushroom-themed festival in Crystal Falls.

Armillaria gallica is a largely subterranean fungus, and it produces fruit bodies that are up to about 10 cm in diameter, yellow-brown, and covered with small scales. On the underside of the caps are gills that are white to creamy or pale orange. The stem may be up to 10 cm long, with a white cobwebby ring that divides the color of the stem into pale orange to brown above, and lighter-colored below. The fungus can develop an extensive system of underground root-like structures, called rhizomorphs, that help it to efficiently decompose dead wood in temperate broadleaf and mixed forests. It has been the subject of considerable scientific research due to its importance as a plant pathogen, its ability to bioluminesce, its unusual life cycle, and its ability to form large and long-lived colonies.

Armillaria luteobubalina
Armillaria luteobubalina, commonly known as the Australian honey fungus, is a species of mushroom in the family Physalacriaceae. Widely distributed in southern Australia, the fungus is responsible for a disease known as Armillaria root rot, a primary cause of Eucalyptus tree death and forest dieback. It is the most pathogenic and widespread of the six Armillaria species found in Australia. The fungus has also been collected in Argentina and Chile. Fruit bodies have cream- to tan-coloured caps that grow up to 10 cm in diameter and stems that measure up to 20 cm long by 1.5 cm thick. The fruit bodies, which appear at the base of infected trees and other woody plants in autumn (March–April), are edible, but require cooking to remove the bitter taste. The fungus is dispersed through spores produced on gills on the underside of the caps, and also by growing vegetatively through the root systems of host trees. The ability of the fungus to spread vegetatively is facilitated by an aerating system that allows it to efficiently diffuse oxygen through rhizomorphs—rootlike structures made of dense masses of hyphae.

Armillaria luteobubalina was first described in 1978, after having been discovered several years earlier growing in a Eucalyptus plantation in southeastern Australia. It distinguished itself from other known Australian Armillaria species by its aggressive pathogenicity. It may take years for infected trees to show signs of disease, leading to an underestimation of disease prevalence. Studies show that the spread of disease in eucalypt forests is associated with infected stumps left following logging operations. Although several methods have been suggested to control the spread of disease, they are largely economically or environmentally unfeasible. Phylogenetic analyses have determined that A. luteobubalina is closely related to A. montagnei and that both of these species are in turn closely related to the Brazilian species A. paulensis. The distribution of A. luteobubalina suggests that it is an ancient species that originated before the separation of the precursor supercontinent Gondwana.

Australian Green Tree Frog
The Australian Green Tree Frog, simply Green Tree Frog in Australia, White's Tree Frog, or Dumpy Tree Frog (Litoria caerulea) is a species of tree frog native to Australia and New Guinea, with introduced populations in New Zealand and the United States. The species belongs to the genus Litoria. It is physiologically similar to some species of the genus, particularly the Magnificent Tree Frog (Litoria splendida) and the Giant Tree Frog (Litoria infrafrenata).

The Green Tree Frog is larger than most Australian frogs, reaching 10 centimetres (4 inches) in length. The average lifespan of the frog in captivity, about sixteen years, is long in comparison with most frogs. Green Tree Frogs are docile and well suited to living near human dwellings. They are often found on windows or inside houses, eating insects drawn by the light.

Due to its physical and behavioural traits, the Green Tree Frog has become one of the most recognisable frogs in its region, and is a popular exotic pet throughout the world. The skin secretions of the frog have antibacterial and antiviral properties that may prove useful in pharmaceutical preparations.

Australian Magpie
The Australian Magpie (Cracticus tibicen) is a medium-sized black and white passerine bird native to Australia and southern New Guinea. A member of the Artamidae, it is closely related to the butcherbirds. At one stage, the Australian Magpie was considered to be three separate species, although zones of hybridisation between forms reinforced the idea of a single species with several subspecies, nine of which are now recognised. The adult Australian Magpie is a fairly robust bird ranging from 37–43 cm (14.5–17 in) in length, with distinctive black and white plumage, red eyes and a solid wedge-shaped bluish-white and black bill. The male and female are similar in appearance, and can be distinguished by differences in back markings. With its long legs, the Australian Magpie walks rather than waddles or hops and spends much time on the ground. This adaptation has led to some authorities maintaining it in its own genus Gymnorhina. Described as one of Australia's most accomplished songbirds, the Australian Magpie has an array of complex vocalisations.

The Australian Magpie is omnivorous, with the bulk of its varied diet made up of invertebrates. It is generally sedentary and territorial throughout its range. Common and widespread, it has adapted well to human habitation and is a familiar bird of parks, gardens and farmland in Australia and New Guinea. Magpies were introduced into New Zealand in the 1860s and are proving to be a pest by displacing native birds. Introductions also occurred in the Solomon Islands and Fiji, where these birds have not become invasive.

Spring in Australia is magpie season, when a small minority of breeding magpies (almost always males) around the country become aggressive and swoop and attack those who approach their nests, especially bike riders. This species is commonly fed by households around the country and is the mascot of several famous Australian sporting teams.

Babakotia
Babakotia is a medium-sized, extinct genus of lemur, or strepsirrhine primate, from Madagascar that contains a single species, Babakotia radofilai. Together with Palaeopropithecus, Archaeoindris, and Mesopropithecus, it forms the family Palaeopropithecidae, commonly known as the sloth lemurs. The name Babakotia comes from the Malagasy name for the Indri, babakoto, to which it and all other sloth lemurs are closely related. Due to its mix of morphological traits that show intermediate stages between the living indriids and the large sloth lemurs, it has helped determine the relationship between both groups and the closely related and extinct monkey lemurs.

Babakotia radofilai and all other sloth lemurs share many traits with living sloths, demonstrating convergent evolution. It had long forearms, curved digits, and highly mobile hip and ankle joints. Its skull was more heavily built than that of indriids, but not as much as in the larger sloth lemurs. Its dentition is similar to that of all other indriids and sloth lemurs. It lived in the northern part of Madagascar and shared its range with at least two other sloth lemur species, Palaeopropithecus ingens and Mesopropithecus dolichobrachion. Babakotia radofilai was primarily a leaf-eater (folivore), though it also ate fruit and hard seeds. It is known only from subfossil remains and may have died out prior to the arrival of humans on the island, but not enough radiocarbon dating has been done with this species to know for certain.

Bacteria
The bacteria (singular: bacterium) are a large group of single-celled, prokaryote microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5×1030) bacteria on Earth, forming much of the world's biomass. Bacteria are vital in recycling nutrients, with many steps in nutrient cycles depending on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. However, most bacteria have not been characterized, and only about half of the phyla of bacteria have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.

There are approximately ten times as many bacterial cells in the human flora of bacteria as there are human cells in the body, with large numbers of bacteria on the skin and as gut flora. The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, and a few are beneficial. However, a few species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy and bubonic plague. The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people a year, mostly in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and in agriculture, so antibiotic resistance is becoming common. In industry, bacteria are important in sewage treatment, the production of cheese and yoghurt through fermentation, as well as in biotechnology, and the manufacture of antibiotics and other chemicals.

Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved independently from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea.

Bald Eagle
The Bald Eagle (Haliaeetus leucocephalus) is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle. Its range includes most of Canada and Alaska, all of the contiguous United States, and northern Mexico. It is found near large bodies of open water with an abundant food supply and old-growth trees for nesting.

In the late 20th century the Bald Eagle was on the brink of extirpation in the continental United States, while flourishing in much of Alaska and Canada. Populations recovered and stabilised, so the species was removed from the U.S. federal government's list of endangered species and transferred to the list of threatened species on July 12, 1995, and it was removed from the List of Endangered and Threatened Wildlife in the Lower 48 States on June 28, 2007.

Bald eagles are not actually bald, the name deriving from the older meaning of the word, "white headed".

Banker horse
The Banker horse is a breed of feral domestic horse (Equus ferus caballus) living on the islands of North Carolina's Outer Banks. It is small, hardy, and has a docile temperament. Descended from domesticated Spanish horses and possibly brought to the Americas in the 16th century, the ancestral foundation bloodstock may have become feral after surviving shipwrecks or being abandoned on the islands by one of the exploratory expeditions led by Lucas Vázquez de Ayllón or Sir Richard Grenville. Populations are found on Ocracoke Island, Shackleford Banks, Currituck Banks, and in the Rachel Carson Estuarine Sanctuary.

Although they can trample plants and ground-nesting animals, and are not considered to be indigenous to the islands, Bankers are allowed to remain because of their historical significance. They survive by grazing on marsh grasses, which supply them with water as well as food, supplemented by temporary freshwater pools.

To prevent overpopulation and inbreeding, and to protect their habitat from being overgrazed, the horses are managed by the National Park Service, the State of North Carolina, and several private organizations. The horses are monitored for diseases such as equine infectious anemia, an outbreak of which was discovered and subsequently eliminated on Shackleford in 1996. They are safeguarded from traffic on the North Carolina Highway 12. Island populations are limited by adoptions and by birth control. Bankers taken from the wild and trained have been used for trail riding, driving, and occasionally for mounted patrols.

Banksia aemula
Banksia aemula, commonly known as the wallum banksia, is a lignotuberous shrub of the Proteaceae family. Found from Bundaberg south to Sydney on the Australian east coast, it is encountered as a shrub or a taller tree to 8 m (25 ft) in coastal heath on deep sandy soil, known as Wallum. It has wrinkled orange bark and shiny green serrated leaves, with green-yellow flower spikes, known as inflorescences, appearing in autumn. The flower spikes turn grey as they age and large grey follicles appear. Banksia aemula resprouts from its woody lignotuber after bushfires.

First described by the botanist Robert Brown in the early 19th century, it derives its specific named 'similar' from its resemblance to the closely related Banksia serrata. No varieties are recognised. It was known for many years in New South Wales as Banksia serratifolia, contrasting with the use of B. aemula elsewhere. However, the former name, originally coined by Richard Anthony Salisbury, proved invalid, and Banksia aemula has been universally adopted as the correct scientific name since 1981. A wide array of mammals, birds, and invertebrates visit the inflorescences and are instrumental in pollination; honeyeaters are particularly prominent visitors. Grown as a garden plant, it is less commonly seen in horticulture than its close relative B. serrata.

Banksia brownii
Banksia brownii, commonly known as Feather-leaved Banksia or Brown's Banksia, is a species of shrub that occurs in southwest Western Australia. An attractive plant with fine feathery leaves and large red-brown flower spikes, it usually grows as an upright bush around two metres (7 ft) high, but can also occur as a small tree or a low spreading shrub. First collected in 1829 and published the following year, it is placed in Banksia subgenus Banksia, section Oncostylis, series Spicigerae. There are two genetically distinct forms.

B. brownii occurs naturally only in two population clusters between Albany and the Stirling Range in southwest Western Australia. In the Stirling Range it occurs among heath on rocky mountain slopes; further south it occurs among Jarrah woodland in shallow nutrient-poor sand. It is rare and endangered in its natural habitat, with all major populations currently threatened by Phytophthora cinnamomi dieback, a disease to which the species is highly susceptible. Other threats include loss of habitat, commercial exploitation and changes to the fire regime.

Highly valued by Australia's horticultural and cut flower industries, B. brownii is widely cultivated in areas not exposed to dieback. It prefers a sheltered position in soil with good drainage, and must be provided with some moisture over summer.

Banksia cuneata
Banksia cuneata, commonly known as Matchstick Banksia or Quairading Banksia, is an endangered species in the Proteaceae family. Endemic to southwest Western Australia, it belongs to Banksia subg. Isostylis, a subgenus of three closely related Banksia species with inflorescences that are dome-shaped heads rather than characteristic Banksia flower spikes. A shrub or small tree up to 5 m (15 ft) high, it has prickly foliage and pink and cream flowers. The common name Matchstick Banksia arises from the blooms in late bud, the individual buds of which resemble matchsticks. The species is pollinated by honeyeaters (Meliphagidae).

Although B. cuneata was first collected before 1880, it was not until 1981 that Australian botanist Alex George formally described and named the species. There are two genetically distinct population groups, but no recognised varieties. This Banksia is classified as endangered, surviving in fragments of remnant bushland in a region which has been 93% cleared for agriculture. As Banksia cuneata is killed by fire and regenerates from seed, it is highly sensitive to bushfire frequency—fires recurring within four years could wipe out populations of plants not yet mature enough to set seed. Banksia cuneata is rarely cultivated, and its prickly foliage limits its utility in the cut flower industry.

Banksia epica
Banksia epica is a shrub that grows on the south coast of Western Australia. A spreading bush with wedge-shaped serrated leaves and large creamy-yellow flower spikes, it grows up to 3½ metres (11½ ft) high. It is known only from two isolated populations in the remote south east of the state, near the western edge of the Great Australian Bight. Both populations occur amongst coastal heath on cliff-top dunes of siliceous sand.

One of the most recently described Banksia species, it was probably seen by Edward John Eyre in 1841, but was not collected until 1973, and was only recognised as a distinct species in 1988. There has been very little research on the species since then, so knowledge of its ecology and cultivation potential is limited. It is placed in Banksia ser. Cyrtostylis, alongside its close relative, the well-known and widely cultivated B. media (Southern Plains Banksia).

Banksia ericifolia
Banksia ericifolia, the Heath-leaved Banksia (also known as the Lantern Banksia or Heath Banksia), is a species of woody shrub of the Proteaceae family native to Australia. It grows in two separate regions of Central and Northern New South Wales east of the Great Dividing Range. Well known for its orange or red autumn inflorescences, which contrast with its green fine-leaved heath-like foliage, it is a medium to large shrub that can reach 6 m (20 ft) high and wide, though is usually half that size. In exposed heathlands and coastal areas it is more often 1–2 m (3–7 ft).

Banksia ericifolia was one of the original Banksia species collected by Joseph Banks around Botany Bay in 1770 and was named by Carl Linnaeus the Younger, son of Carolus Linnaeus, in 1782. A distinctive plant, it has split into two subspecies: Banksia ericifolia subspecies ericifolia of the Sydney region and Banksia ericifolia subspecies macrantha of the New South Wales Far North Coast which was recognized in 1996.

Banksia ericifolia has been widely grown in Australian gardens on the east coast for many years as well as being used to a limited extent in the cut flower industry. Compact dwarf cultivars such as Banksia 'Little Eric' have become more popular in recent years with the trend toward smaller gardens.

Banksia integrifolia
Banksia integrifolia, commonly known as Coast Banksia, is a species of tree that grows along the east coast of Australia. One of the most widely distributed Banksia species, it occurs between Victoria and Central Queensland in a broad range of habitats, from coastal dunes to mountains. It is highly variable in form, but is most often encountered as a tree up to 25 metres (82 ft) in height. Its leaves have dark green upper surfaces and white undersides, a contrast that can be striking on windy days.

It is one of the four original Banksia species collected by Sir Joseph Banks in 1770, and one of four species published in 1782 as part of Carolus Linnaeus the Younger's original description of the genus. It has had a complicated taxonomic history, with numerous species and varieties ascribed to it, only to be rejected or promoted to separate species. The taxonomy is now largely settled, with three subspecies recognised: B. integrifolia subsp. integrifolia, B. integrifolia subsp. compar and B. integrifolia subsp. monticola.

A hardy and versatile garden plant, B. integrifolia is widely planted in Australian gardens. It is a popular choice for parks and streetscapes, and has been used for bush revegetation and stabilisation of dunes. Its hardiness has prompted research into its suitability for use as a rootstock in the cut flower trade, but has also caused concerns about its potential to become a weed outside its natural habitat.

Banksia menziesii
Banksia menziesii, commonly known as firewood banksia, is a species of flowering plant in the genus Banksia. It is a gnarled tree up to 10 m (35 ft) tall, or a lower spreading 1–3 m (4–10 ft) shrub in the more northern parts of its range. The serrated leaves are dull green with new growth a paler grey green. The prominent autumn and winter inflorescences are often two-coloured red or pink and yellow, and their colour has given rise to more unusual common names such as port wine banksia and strawberry banksia. Yellow blooms are rarely seen.

First described by the botanist Robert Brown in the early 19th century, no separate varieties of Banksia menziesii are recognised. It is found in Western Australia, from the Perth (32° S) region north to the Murchison River (27° S), and generally grows on sandy soils, in scrubland or low woodland. Banksia menziesii provides food for a wide array of invertebrate and vertebrate animals; birds and in particular honeyeaters are prominent visitors. A relatively hardy plant, Banksia menziesii is commonly seen in gardens, nature strips and parks in Australian urban areas with Mediterranean climates, but its sensitivity to dieback from the soil-borne water mould Phytophthora cinnamomi makes it short-lived in places with humid summers, such as Sydney. Banksia menziesii is widely used in the cut flower industry both in Australia and overseas.

Banksia prionotes
Banksia prionotes, commonly known as Acorn Banksia or Orange Banksia, is a species of shrub or tree of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 10 m (30 ft) in height. It can be much smaller in more exposed areas or in the north of its range. This species has serrated, dull green leaves and large, bright flower spikes, initially white before opening to a bright orange. Its common name arises from the partly opened inflorescence, which is shaped like an acorn. The tree is a popular garden plant and also of importance to the cut flower industry.

Banksia prionotes was first described in 1840 by English botanist John Lindley, probably from material collected by James Drummond the previous year. There are no recognised varieties, although it has been known to hybridise with Banksia hookeriana. Widely distributed in south-west Western Australia, B. prionotes is found from Shark Bay (25° S) in the north, south as far as Kojonup (33°50′S). It grows exclusively in sandy soils, and is usually the dominant plant in scrubland or low woodland. Pollinated by birds, it provides food for a wide array of vertebrate and invertebrate animals in the autumn and winter months. It is an important source of food for honeyeaters (Meliphagidae), and is critical to their survival in the Avon Wheatbelt region, where it is the only nectar-producing plant in flower at some times of the year.

Banksia scabrella
Banksia scabrella, commonly known as the Burma Road Banksia, is a species of woody shrub in the genus Banksia. It is classified in the series Abietinae, a group of several species of shrubs with small round or oval inflorescences. It occurs in a number of isolated populations south of Geraldton, Western Australia, with the largest population being south and east of Mount Adams. Found on sandy soils in heathland or shrubland, it grows to 2 m (7 ft) high and 3 m (10 ft) across with fine needle-like leaves. Appearing in spring and summer, the inflorescences are round to oval in shape and tan to cream with purple styles. Banksia scabrella is killed by fire and regenerates by seed.

Originally collected in 1966, Banksia scabrella was one of several species previously considered to be forms of Banksia sphaerocarpa, before it was finally described by banksia expert Alex George in his 1981 revision of the genus. Like many members of the Abietinae, it is rarely seen in cultivation; however, it has been described as having horticultural potential.

Banksia sessilis
Banksia sessilis, commonly known as Parrot Bush, is a species of shrub or tree in the plant genus Banksia in the Proteaceae family. It had been known as Dryandra sessilis until 2007, when the genus Dryandra was sunk into Banksia. Widespread throughout southwest Western Australia, it is found on sandy soils over laterite or limestone, often as an understorey plant in open forest, woodland or shrubland. Encountered as a shrub or small tree up to 6 m (20 ft) in height, it has prickly dark green leaves and dome-shaped cream-yellow flowerheads. Flowering from winter through to late spring, it provides a key source of food—both the nectar and the insects it attracts—for honeyeaters in the cooler months, and species diversity is reduced in areas where there is little or no parrot bush occurring. Several species of honeyeater, some species of native bee, and the European Honey Bee seek out and consume the nectar, while the Long-billed Black Cockatoo and Australian Ringneck eat the seed. The life cycle of Banksia sessilis is adapted to regular bushfires. Killed by fire and regenerating by seed afterwards, each shrub generally produces many flowerheads and a massive amount of seed. It can recolonise disturbed areas, and may grow in thickets.

Banksia sessilis has a somewhat complicated taxonomic history. It was collected from King George Sound in 1801 and described by Robert Brown in 1810 as Dryandra floribunda, a name by which it was known for many years. However, Joseph Knight had published the name Josephia sessilis in 1809, which had precedence due to its earlier date, and the specific name was formalised in 1924. Four varieties are recognised. It is a prickly plant with little apparent horticultural potential, and none of the varieties are commonly seen in cultivation. A profuse producer of nectar, B. sessilis is valuable to the beekeeping industry.

Banksia sphaerocarpa
Banksia sphaerocarpa, commonly known as the Fox Banksia or Round-fruit Banksia, is a species of shrub or tree in the plant genus Banksia (family Proteaceae). It is generally encountered as a 1–2 m (3–7 ft) high shrub, and is usually smaller in the north of its range. This species has narrow green leaves, and brownish, orange or yellow round flower spikes which may be seen from January to July. It is widely distributed across the southwest of Western Australia, growing exclusively in sandy soils. It is usually the dominant plant in scrubland or low woodland. It is pollinated by, and is a food source for, birds, mammals, and insects.

First described in 1810 by botanist Robert Brown, B. sphaerocarpa has a complicated taxonomic history, and several taxa once classified as part of a broadly defined B. sphaerocarpa have since been named as species in their own right. At present, most authorities recognise five varieties; the largest variety, B. sphaerocarpa var. dolichostyla (Ironcap Banksia), is sometimes given species rank as B. dolichostyla. B. sphaerocarpa is classified as Not Threatened under the Wildlife Conservation Act of Western Australia, although two varieties have been placed on the Declared Rare and Priority Flora List—var. latifolia  has been declared a Priority Two – Poorly Known taxon, and var. dolichostyla has been Declared Rare Flora. None of the varieties are commonly seen in cultivation.

Banksia Hairpin
The Banksia Hairpin (Banksia spinulosa) is a species of woody shrub, of the genus Banksia in the Proteaceae family, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to north Queensland, generally on sandstone though sometimes also clay soils. It generally grows as a small shrub to 2 m in height, though can be a straggly tree to 6 m. It has long narrow leaves with inflorescences which can vary considerably in coloration; while the spikes are gold or less commonly yellowish, the emergent styles may be a wide range of colours–from black, purple, red, orange or yellow.

Banksia spinulosa was named by James Edward Smith in England in 1793, after being collected by John White, most likely in 1792. He gave it the common name Prickly-leaved Banksia, though this has fallen out of use. With four currently recognised varieties, the species has had a complicated taxonomic history, with two varieties initially described as separate species in the early 19th century. A fourth from the New England region has only recently been described. However there has been disagreement whether one, var. cunninghamii, is distinct enough to once again have specific status. The pre-eminent authority on Banksia, Alex George, concedes there is still more work to be done on the Banksia spinulosa complex.

The Hairpin Banksia is pollinated by and provides food for a wide array of vertebrate and invertebrate animals in the autumn and winter months. Its floral display and fine foliage have made it a popular garden plant with many horticultural selections available. Given recent trends toward smaller gardens, compact dwarf forms of Banksia spinulosa have become popular; the first available, Banksia 'Birthday Candles', has achieved a great deal of commercial success and wide recognition, and has been followed by several others.

Banksia telmatiaea
Banksia telmatiaea, commonly known as Swamp Fox Banksia or rarely Marsh Banksia, is a shrub that grows in marshes and swamps along the lower west coast of Australia. It grows as an upright bush up to 2 m (7 ft) tall, with narrow leaves and a pale brown flower spike, which can produce profuse quantities of nectar. First collected in the 1840s, it was not published as a species until 1981; as with several other similar species it was previously included in B. sphaerocarpa (Fox Banksia).

The shrub grows amongst scrubland in seasonally wet lowland areas of the coastal sandplain between Badgingarra and Serpentine in Western Australia. A little studied species, not much is known of its ecology or conservation biology. Reports do suggest, however, that it is pollinated by a variety of birds and small mammals. Like many members of series 'Abietinae', it has not been considered to have much horticultural potential and is rarely cultivated.

Banksia violacea
Banksia violacea, commonly known as Violet Banksia, is a species of shrub or tree in the plant genus Banksia (family Proteaceae). It generally grows as a small shrub to 1.5 m (5 ft) high with fine narrow leaves, and is best known for its unusually coloured dark purple-violet inflorescences. The colour of the inflorescences, short leaves, and flattened follicles which are sticky when young, help identify this species from others in the field. It is found in low shrubland in southern regions of Western Australia from Esperance in the east to Narrogin in the west, growing exclusively in sandy soils.

First described in 1927 by West Australian botanist Charles Gardner, the species was at one stage considered a variety of B. sphaerocarpa. Although there are no recognised subspecies or varieties, both lignotuberous and nonlignotuberous forms exist for Banksia violacea. Wasps, ants and flies have been recorded visiting flower spikes. Banksia violacea is classified as Not Threatened under the Wildlife Conservation Act of Western Australia. Regarded as of little value to floriculture, it is rarely cultivated.

Barn Swallow
The Barn Swallow (Hirundo rustica) is the most widespread species of swallow in the world. A distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings, it is found in Europe, Asia, Africa and the Americas. In Anglophone Europe it is just called the Swallow; in Northern Europe it is the only common species called a "swallow" rather than a "martin".

There are six subspecies of Barn Swallow, which breed across the Northern Hemisphere. Four are strongly migratory, and their wintering grounds cover much of the Southern Hemisphere as far south as central Argentina, the Cape Province of South Africa, and northern Australia. Its huge range means that the Barn Swallow is not endangered, although there may be local population declines due to specific threats, such as the construction of an international airport near Durban.

The Barn Swallow is a bird of open country which normally uses man-made structures to breed and consequently has spread with human expansion. It builds a cup nest from mud pellets in barns or similar structures and feeds on insects caught in flight. This species lives in close association with humans, and its insect-eating habits mean that it is tolerated by man; this acceptance was reinforced in the past by superstitions regarding the bird and its nest. There are frequent cultural references to the Barn Swallow in literary and religious works due to both its living in close proximity to humans and its conspicuous annual migration. The Barn Swallow is the national bird of Estonia.

Beagle
The Beagle is a breed of small to medium-sized dog. A member of the Hound Group, it is similar in appearance to the Foxhound but smaller, with shorter legs and longer, softer ears. Beagles are scent hounds, developed primarily for tracking hare, rabbit, and other game. They have a keen sense of smell and tracking instinct that sees them employed as detection dogs for prohibited agricultural imports and foodstuffs in quarantine around the world. They are popular as pets because of their size, even temper, and lack of inherited health problems. These characteristics also make them the dog of choice for animal testing.

Although beagle-type dogs have existed for over 2,000 years, the modern breed was developed in Great Britain around the 1830s from several breeds, including the Talbot Hound, the North Country Beagle, the Southern Hound, and possibly the Harrier.

Beagles have been depicted in popular culture since Elizabethan times in literature and paintings, and more recently in film, television and comic books. Snoopy of the comic strip Peanuts has been promoted as "the world's most famous beagle".

Birds
Birds (class Aves) are winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. There are around 10,000 living species, making them the most varied of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from the 5 cm Bee Hummingbird to the 2.75 m Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Ma (million years ago), and the earliest known bird is the Late Jurassic Archaeopteryx, c 150–145 Ma. Most paleontologists regard birds as the only clade of dinosaurs to have survived the Cretaceous–Tertiary extinction event approximately 65.5 Ma.

Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. All living species of birds have wings - the now extinct flightless Moa of New Zealand were the only exceptions. Wings are evolved forelimbs, and most bird species can fly, with some exceptions including ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight. Some birds, especially corvids and parrots, are among the most intelligent animal species; a number of bird species have been observed manufacturing and using tools, and many social species exhibit cultural transmission of knowledge across generations.

Many species undertake long distance annual migrations, and many more perform shorter irregular movements. Birds are social; they communicate using visual signals and through calls and songs, and participate in social behaviours including cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous ("many females") or, rarely, polyandrous ("many males"). Eggs are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.

Many species are of economic importance, mostly as sources of food acquired through hunting or farming. Some species, particularly songbirds and parrots, are popular as pets. Other uses include the harvesting of guano (droppings) for use as a fertiliser. Birds figure prominently in all aspects of human culture from religion to poetry to popular music. About 120–130 species have become extinct as a result of human activity since the 17th century, and hundreds more before then. Currently about 1,200 species of birds are threatened with extinction by human activities, though efforts are underway to protect them.

Black Currawong
The Black Currawong (Strepera fuliginosa), also known locally as the Black Jay, is a large passerine bird native to Tasmania. One of three currawong species in the genus Strepera, it is closely related to the butcherbirds and Australian Magpie within the family Artamidae. It is a large crow-like bird, around 50 cm long on average, with yellow irises, a heavy bill, and black plumage with white wing patches. The male and female are similar in appearance. Three subspecies are recognised, one of which, Strepera fuliginosa colei of King Island, is vulnerable to extinction.

Within its range, the Black Currawong is generally sedentary, although populations at higher altitudes relocate to lower areas during the cooler months. The habitat includes densely forested areas as well as alpine heathland. It is rare below altitudes of 200 m (700 ft). Omnivorous, it has a diet that includes a variety of berries, invertebrates, and small vertebrates. Less arboreal than the Pied Currawong, the Black Currawong spends more time foraging on the ground. It roosts and breeds in trees.

Black Vulture
The Black Vulture, Coragyps atratus, also known as the American Black Vulture, is a bird in the New World vulture family whose range extends from the southeastern United States to Central Chile and Uruguay in South America. Although a common and widespread species, it has a somewhat more restricted distribution than its compatriot, the Turkey Vulture, which breeds well into Canada and south to Tierra del Fuego. Despite the similar name and appearance, this species is unrelated to the Eurasian Black Vulture. The latter species is an Old World vulture in the family Accipitridae (which includes eagles, hawks, kites and harriers), whereas the American species is a New World vulture. It is the only extant member of the genus Coragyps, which is in the family Cathartidae. It inhabits relatively open areas which provide scattered forests or shrublands. With a wingspan of 1.5 m (5 ft) the Black Vulture is a large bird though relatively small for a vulture. It has black plumage, a featherless, grayish-black head and neck, and a short, hooked beak.

The Black Vulture is a scavenger and feeds on carrion, but will also eat eggs or kill newborn animals. In areas populated by humans, it also feeds at garbage dumps. It finds its meals either by using its keen eyesight or by following other (New World) vultures, which possess a keen sense of smell. Lacking a syrinx—the vocal organ of birds—its only vocalizations are grunts or low hisses. It lays its eggs in caves or hollow trees or on the bare ground, and generally raises two chicks each year, which it feeds by regurgitation. In the United States, the vulture receives legal protection under the Migratory Bird Treaty Act of 1918. This vulture also appeared in Mayan codices.

Blue Iguana
The Blue Iguana or Grand Cayman Iguana (Cyclura lewisi) is a critically endangered species of lizard of the genus Cyclura endemic to the island of Grand Cayman. Previously listed as a subspecies of the Cuban Iguana, it was reclassified as a separate species in 2004 because of genetic differences discovered four years earlier. The Blue Iguana is one of the longest-living species of lizard (possibly up to 69 years). The record is 67 years.

The Blue Iguana prefers dwelling in rocky, sunlit, open areas in dry forests or near the shore, as the females must dig holes in the sand to lay eggs in June and July. A possible second clutch is laid in September. The Blue Iguana's vegetarian diet includes plants, fruits, and flowers. Its coloration is tan to gray with a bluish cast that is more pronounced during the breeding season and more so in males. It is large and heavy-bodied with a dorsal crest of short spines running from the base of the neck to the end of the tail.

The fossil record indicates that the Blue Iguana was abundant before European colonization; but fewer than 15 animals remained in the wild by 2003, and this wild population was predicted to become extinct within the first decade of the 21st century. The species' decline is mainly being driven by predation by feral pets (cats and dogs) and indirectly by the destruction of their natural habitat as fruit farms are converted to pasture for cattle grazing. Since 2004, 219 captive-bred animals have been released into a preserve on Grand Cayman run by a partnership headed by the Durrell Wildlife Conservation Trust, in an attempt to save the species. At least five non-profit organizations are working with the government of the Cayman Islands to ensure the survival of the Blue Iguana.

Blue whale
The Blue whale (Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales (called Mysticeti). At over 33 m in length and 180 metric ton or more in weight, it is the largest animal ever known to have existed.

Long and slender, the blue whale's body can be various shades of bluish-grey dorsally and somewhat lighter underneath. There are at least three distinct subspecies: B. m. musculus of the North Atlantic and North Pacific, B. m. intermedia of the Southern Ocean and B. m. brevicauda (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. B. m. indica, found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill.

Blue whales were abundant in nearly all the oceans until the beginning of the twentieth century. For over 40 years, they were hunted almost to extinction by whalers until protected by the international community in 1966. A 2002 report estimated there were 5,000 to 12,000 blue whales worldwide, located in at least five groups. More recent research into the Pygmy subspecies suggests this may be an underestimate. Before whaling, the largest population was in the Antarctic, numbering approximately 239,000 (range 202,000 to 311,000). There remain only much smaller (around 2,000) concentrations in each of the North-East Pacific, Antarctic, and Indian Ocean groups. There are two more groups in the North Atlantic, and at least two in the Southern Hemisphere.

Bobcat
The Bobcat (Lynx rufus) is a North American mammal of the cat family, Felidae. With twelve recognized subspecies, it ranges from southern Canada to northern Mexico, including most of the continental United States. The Bobcat is an adaptable predator that inhabits wooded areas, as well as semi-desert, urban edge, forest edges and swampland environments. It persists in much of its original range and populations are healthy.

With a gray to brown coat, whiskered face, and black-tufted ears, the Bobcat resembles the other species of the mid-sized Lynx genus. It is smaller than the Canada Lynx, with which it shares parts of its range, but is about twice as large as the domestic cat. It has distinctive black bars on its forelegs and a black-tipped, stubby tail, from which it derives its name.

Though the Bobcat prefers rabbits and hares, it will hunt anything from insects and small rodents to deer. Prey selection depends on location and habitat, season, and abundance. Like most cats, the bobcat is territorial and largely solitary, although there is some overlap in home ranges. It uses several methods to mark its territorial boundaries, including claw marks and deposits of urine or feces. The Bobcat breeds from winter into spring and has a gestation period of about two months.

Although Bobcats have been hunted extensively by humans, both for sport and fur, their population has proven resilient. The elusive predator features in Native American mythology and the folklore of European settlers.

Bog turtle
The bog turtle (Glyptemys muhlenbergii) is a semiaquatic turtle that is endemic to the eastern United States. It was discovered in Pennsylvania in the 18th century and first scientifically described in 1801. It is the smallest North American turtle, measuring about 10 cm long when fully grown. Although the bog turtle is similar in appearance to the painted or spotted turtles, its closest relative is the somewhat larger wood turtle. The bog turtle can be found from Vermont in the north south to Georgia and west to Ohio. Diurnal and secretive, it spends most of its time buried in mud and, during the winter months, in hibernation. The bog turtle is omnivorous, feeding mainly on small invertebrates.

Adult bog turtles weigh 110 g on average. Their skins and shells are typically dark brown, with a distinctive orange spot on each side of the neck. Considered threatened at the federal level, the bog turtle is protected under the United States' Endangered Species Act. Invasive plants and urban development have eradicated much of the bog turtle's habitat, substantially reducing its numbers. Demand for the bog turtle is high in the black market pet trade, partly because of its small size and unique characteristics. Various private projects have been undertaken in an attempt to reverse the decline in the turtle's population.

The turtle has a low reproduction rate; females lay an average of three eggs per clutch and lay one clutch per year. The young tend to grow rapidly, reaching sexual maturity between the ages of 4 and 10 years old. Bog turtles live for an average of 20 to 30 years in the wild. Since 1973, the Bronx Zoo has successfully bred bog turtles in captivity.

Boletus edulis
Boletus edulis, commonly known as penny bun, porcino or cep, is a basidiomycete fungus, and the type species of the genus Boletus. Widely distributed in the Northern Hemisphere across Europe, Asia, and North America, it does not occur naturally in the Southern Hemisphere, although it has been introduced to southern Africa and New Zealand. Several closely related European mushrooms formerly thought to be varieties or forms of B. edulis have been shown using molecular phylogenetic analysis to be distinct species. The western North American species commonly known as the California king bolete (Boletus edulis var. grandedulis) is a large, darker-coloured variant that was first formally identified in 2008.

The fungus grows in deciduous and coniferous forests and tree plantations, forming symbiotic ectomycorrhizal associations with living trees by enveloping sheaths of fungal tissue around their underground roots. The fungus produces spore-bearing fruit bodies above ground in summer and autumn. The fruit body consists of a large and imposing brown cap which on occasion can reach at least 35 cm in diameter and 3 kg in weight. Like other boletes, it has tubes extending downward from the underside of the cap, rather than gills; spores are released at maturity through the tube openings, or pores. The pore surface of the B. edulis fruit body is whitish when young, but ages to a greenish-yellow. The stout stipe, or stem, is white or yellowish in colour, up to 25 cm (10 in) tall and 10 cm thick, and partially covered with a raised network pattern, or reticulations.

Prized as an ingredient in various foods, B. edulis is an edible mushroom held in high regard in many cuisines, and is commonly prepared and eaten in soups, pasta, or risotto. The mushroom is low in fat and digestible carbohydrates, and high in protein, vitamins, minerals and dietary fibre. Although it is sold commercially, it has not been successfully grown in cultivation. Available fresh in autumn in Central, Southern and Northern Europe, it is most often dried, packaged and distributed worldwide. Keeping its flavour after drying, it is then reconstituted and used in cooking. Boletus edulis is one of the few fungi that are sold pickled. The fungus also produces a variety of organic compounds with a diverse spectrum of biological activity, including the steroid derivative ergosterol, a sugar binding protein, antiviral compounds, antioxidants, and phytochelatins, which give the organism resistance to toxic heavy metals.

Bone Wars
The Bone Wars, also known as the "Great Dinosaur Rush", refers to a period of intense fossil speculation and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope (of the Academy of Natural Sciences in Philadelphia) and Othniel Charles Marsh (of the Peabody Museum of Natural History at Yale). Each of the two paleontologists used underhanded methods to try to out-compete the other in the field, resorting to bribery, theft, and destruction of bones. Each scientist also attacked the other in scientific publications, seeking to ruin his credibility and have his funding cut off.

Their search for fossils led them west to rich bone beds in Colorado, Nebraska, and Wyoming. From 1877 to 1892, both paleontologists used their wealth and influence to finance their own expeditions and to procure services and dinosaur bones from fossil hunters. By the end of the Bone Wars, both men had exhausted their funds in the pursuit of paleontological supremacy.

Cope and Marsh were financially and socially ruined by their attempts to disgrace each other, but their contributions to science and the field of paleontology were massive, and provided substantial material for further work—both scientists left behind many unopened boxes of fossils after their deaths. The efforts of the two men led to over 142 new species of dinosaurs being discovered and described. The products of the Bone Wars resulted in an increase in knowledge of prehistoric life, and sparked the public's interest in dinosaurs, leading to continued fossil excavation in North America in the decades to follow. Several historical books and fictional adaptations have been published about this period of intense fossil-hunting activity.

California Condor
The California Condor (Gymnogyps californianus) is a North American species of bird in the New World vulture family Cathartidae and the largest North American land bird. Currently, this condor inhabits only the Grand Canyon area, Zion National Park, and western coastal mountains of California and northern Baja California. Although other fossil members are known, it is the only surviving member of the genus Gymnogyps.

It is a large, black vulture with patches of white on the underside of the wings and a largely bald head with skin color ranging from yellowish to a bright red, depending on the bird's mood. It has the largest wingspan of any bird found in North America and is one of the heaviest. The condor is a scavenger and eats large amounts of carrion. It is one of the world's longest-living birds, with a lifespan of up to 50 years.

Condor numbers dramatically declined in the 20th century due to poaching, lead poisoning, and habitat destruction. Eventually, a conservation plan was put in place by the United States government that led to the capture of all the remaining wild condors in 1987. These 22 birds were bred at the San Diego Wild Animal Park and the Los Angeles Zoo. Numbers rose through captive breeding and, beginning in 1991, condors have been reintroduced into the wild. The project is the most expensive species conservation project ever undertaken in the United States. The California Condor is one of the world's rarest bird species. As of March 2010, there are 349 condors known to be living, including 180 in the wild.

The condor is a significant bird to many Californian Native American groups and plays an important role in several of their traditional myths.

Cane Toad
The Cane Toad (Bufo marinus), also known as the Giant Neotropical Toad or Marine Toad, is a large, terrestrial true toad native to Central and South America, but has since been introduced to various islands throughout Oceania and the Caribbean. It is a member of the subgenus Rhinella of the genus Bufo, which includes many different true toad species found throughout Central and South America. The cane toad is a prolific breeder; females lay single-clump spawns with thousands of eggs. Its reproductive success is partly because of opportunistic feeding: it has a diet, unusual among Anurans, of both dead and living matter. Adults average 10 – in length; the largest recorded specimen weighed 2.65 kilograms (5.8 lb) with a length of 38 cm from snout to vent.

The cane toad has poison glands, and the tadpoles are highly toxic to most animals if ingested. Because of its voracious appetite, the cane toad has been introduced to many regions of the Pacific and the Caribbean islands as a method of agricultural pest control. The species derives its common name from its use against the cane beetle (Dermolepida albohirtum). The cane toad is now considered a pest and an invasive species in many of its introduced regions; of particular concern is that its toxic skin kills many animals—native predators and otherwise—when ingested.

Cattle Egret
The Cattle Egret (Bubulcus ibis) is a cosmopolitan species of heron (family Ardeidae) found in the tropics, subtropics and warm temperate zones. It is the only member of the monotypic genus Bubulcus, although some authorities regard its two subspecies as full species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world.

It is a stocky white bird adorned with buff plumes in the breeding season which nests in colonies, usually near bodies of water and often with other wading birds. The nest is a platform of sticks in trees or shrubs. Unlike most other herons, it feeds in relatively dry grassy habitats, often accompanying cattle or other large mammals, since it catches insect and small vertebrate prey disturbed by these animals. Some populations of the Cattle Egret are migratory and others show post-breeding dispersal.

The adult Cattle Egret has few predators, but birds or mammals may raid its nests, and chicks may be lost to starvation, calcium deficiency or disturbance from other large birds. This species removes ticks and flies from cattle, but it can be a safety hazard at airfields, and has been implicated in the spread of tick-borne animal diseases.

Cell biology
In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel), also sometimes referred to as the "control center", is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression — the nucleus is therefore the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and separates its contents from the cellular cytoplasm, and the nuclear lamina, a meshwork within the nucleus that adds mechanical support, much like the cytoskeleton supports the cell as a whole. Because the nuclear membrane is impermeable to most molecules, nuclear pores are required to allow movement of molecules across the envelope. These pores cross both of the membranes, providing a channel that allows free movement of small molecules and ions. The movement of larger molecules such as proteins is carefully controlled, and requires active transport regulated by carrier proteins. Nuclear transport is crucial to cell function, as movement through the pores is required for both gene expression and chromosomal maintenance.

Although the interior of the nucleus does not contain any membrane-bound subcompartments, its contents are not uniform, and a number of subnuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes. The best known of these is the nucleolus, which is mainly involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA.

Common Chiffchaff
The Common Chiffchaff, or simply the Chiffchaff, Phylloscopus collybita, is a common and widespread leaf-warbler which breeds in open woodlands throughout northern and temperate Europe and Asia.

It is a migratory passerine which winters in southern and western Europe, southern Asia and north Africa. Greenish-brown above and off-white below, it is named onomatopoeically for its simple chiff-chaff song. It has a number of subspecies, some of which are now treated as full species. The female builds a domed nest on or near the ground, and assumes most of the responsibility for brooding and feeding the chicks, whilst the male has little involvement in nesting, but defends his territory against rivals, and attacks potential predators.

A small insectivorous bird, it is subject to predation by mammals, such as cats and mustelids, and birds, particularly hawks of the genus Accipiter. It may also acquire external or internal parasites. Its large range and population mean that its status is secure, although one subspecies is probably extinct.

Chorioactis
Chorioactis is a genus of fungus that contains the single species Chorioactis geaster; the mushroom is commonly known as the devil’s cigar or the Texas star in the United States, while in Japan it is called kirinomitake (キリノミタケ). This extremely rare mushroom is notable for its unusual appearance and disjunct distribution: it is only found only in select locales in Texas and Japan. The fruit body, which grows on the stumps or dead roots of cedar elms (in Texas) or dead oaks (in Japan), somewhat resembles a dark brown or black cigar before it splits open radially into a starlike arrangement of four to seven leathery rays. The interior surface of the fruit body bears the spore-bearing tissue known as the hymenium, and is colored white to brown, depending on its age. Fruit body opening can be accompanied by a distinct hissing sound and the release of a smoky cloud of spores.

Fruit bodies were first collected in Austin, Texas in 1893, and the species was named Urnula geaster; it was later found in Kyushu in 1937, but the mushroom was not reported again in Japan until 1973. Although the new genus Chorioactis was proposed to accommodate the unique species a few years after its original discovery, it was not until 1968 that it was accepted as a valid genus. Its classification has also been a source of confusion. Historically, Chorioactis was placed in the Sarcosomataceae family of fungi, despite inconsistencies in the microscopic structure of the ascus, the saclike structure in which spores are formed. Phylogenetic analyses of the past decade have clarified the fungus's classification: Chorioactis, along with three other genera, make up the Chorioactidaceae family, a grouping of related fungi formally acknowledged in 2008. In 2009, Japanese researchers reported discovering a form of the fungus missing the sexual stage of its life cycle; this asexual state was named Kumanasamuha geaster.

Chromatophores
Chromatophores are pigment-containing and light-reflecting cells found in amphibians, fish, reptiles, crustaceans, and cephalopods. They are largely responsible for generating skin and eye colour in cold-blooded animals and are generated in the neural crest during embryonic development. Mature chromatophores are grouped into subclasses based on their colour (more properly "hue") under white light: xanthophores (yellow), erythrophores (red), iridophores (reflective / iridescent), leucophores (white), melanophores (black/brown) and cyanophores (blue). The term can also refer to coloured, membrane associated vesicles found in some forms of photosynthetic bacteria.

Some species can rapidly change colour through mechanisms that translocate pigment and reorient reflective plates within chromatophores. This process, often used as a type of camouflage, is called physiological colour change. Cephalopods such as octopus have complex chromatophore organs controlled by muscles to achieve this, while vertebrates such as chameleons generate a similar effect by cell signaling. Such signals can be hormones or neurotransmitters and may be initiated by changes in mood, temperature, stress or visible changes in local environment.

Unlike cold-blooded animals, mammals and birds have only one class of chromatophore-like cell type: the melanocyte. The cold-blooded equivalent, melanophores, are studied by scientists to understand human disease and used as a tool in drug discovery.

Chrysiridia ripheus
The Madagascan sunset moth or simply sunset moth, Chrysiridia rhipheus, is a day-flying moth of the Uraniidae family. It is considered to be one of the most impressive and beautiful Lepidoptera. Famous worldwide, it is featured in most coffee table books on the Lepidoptera and is much sought after by collectors. It is very colourful, though the iridescent parts of the wings do not have pigment; rather the colours originate from optical interference. Adult moths have a wingspan of 7–9 centimetres (3–3½ in).

The moth was considered to be a butterfly by Dru Drury, who described it in 1773 and placed it in the genus Papilio. Jacob Hübner placed it in the moth genus Chrysiridia in 1823. Later redescriptions led to junior synonyms such as Chrysiridia madagascariensis (Lesson, 1831).

At first the moth was thought to be from China or Bengal, but was later found to be endemic to Madagascar. It is found throughout the year in most parts of the island, with peak populations between March and August, and smallest numbers between October and December. Females lay about 80 eggs under the leaves of Omphalea spp. The caterpillars are whitish-yellow with black spots and red feet and are covered in club-ended black setae. Silk spun from the mouth helps the caterpillars hold onto smooth leaves and climb back to the plant when they fall. After completing four instars, the caterpillars spin an open network cocoon. The pupal stage lasts from 17 to 23 days. Chrysiridia rhipheus is the sole specialist herbivore of the four species of Omphalea in Madagascar. Omphalea is toxic: the toxins are sequestered by the feeding caterpillar and retained in the pupal and adult stages. Thousands of these moths migrate between the eastern and western ranges of their host plants.

Cleveland Bay
The Cleveland Bay is a breed of horse that originated in England during the 17th century, named after its colouring and the Cleveland district of Yorkshire. It is a well-muscled horse, with legs that are strong but short in relation to the body. The horses are always bay in colour, although a few light hairs in the mane and tail are characteristic of some breed lines. It is the oldest established horse breed in England, and the only non-draught horse developed in Great Britain. The ancestors of the breed were developed during the Middle Ages for use as pack horses, when they gained their nickname of "Chapman Horses". These pack horses were crossbred with Andalusian and Barb blood, and later with Arabians and Thoroughbreds, to create the Cleveland Bay of today. Over the years, the breed became lighter in frame as they were employed more as carriage and riding horses. The popularity of the Cleveland Bay has greatly fluctuated since it was first imported to the United States in the early 1800s. Despite serious declines in the population after Second World War, the breed has experienced a resurgence in popularity since the 1970s, although only around 550 horses existed worldwide as of 2006.

They have been patronized by members of the royal family throughout their history, and they are still used to pull carriages in royal processions today. The breed has also been used to develop and improve several warmblood and draught horse breeds. Today they are used for farm work and driving, as well as under-saddle work. They are particularly popular for fox hunting and show jumping, both pure blooded and when crossed with Thoroughbreds. The Cleveland Bay is a rare breed, and both the United Kingdom-based Rare Breeds Survival Trust and the United States-based American Livestock Breeds Conservancy consider the population to be at critical limits for extinction.

Cochineal
The Cochineal (Dactylopius coccus) is a scale insect in the suborder Sternorrhyncha, from which the crimson-coloured dye carmine is derived. A primarily sessile parasite native to tropical and subtropical South America and Mexico, this insect lives on cacti from the genus Opuntia, feeding on plant moisture and nutrients.

The insect produces carminic acid that deters predation by other insects. Carminic acid, which occurs as 17-24% of the weight of the dry insects, can be extracted from the insect's body and eggs and mixed with aluminum or calcium salts to make carmine dye (also known as cochineal). Carmine is today primarily used as a food colouring and for cosmetics.

The carmine dye was used in Central America in the 15th century for coloring fabrics and became an important export good during the colonial period. After synthetic pigments and dyes such as alizarin were invented in the late 19th century, natural-dye production gradually diminished. Health fears over artificial food additives, however, have renewed the popularity of cochineal dyes, and the increased demand has made cultivation of the insect profitable again, with Peru being the largest exporter.

There are other species in the genus Dactylopius that can be used to produce cochineal extract, but they are extremely difficult to distinguish from D. coccus, even for expert taxonomists, and the latter scientific name (and the vernacular "cochineal insect") is therefore commonly used when one is actually referring to other biological species. The primary biological distinctions between species are minor differences in host plant preferences, in addition to very different geographic distributions.

Cretaceous–Tertiary extinction event
The Cretaceous–Tertiary extinction event, which occurred approximately 65.5 million years ago (Ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time. Widely known as the K–T extinction event, it is associated with a geological signature known as the K–T boundary, usually a thin band of sedimentation found in various parts of the world. K is the traditional abbreviation for the Cretaceous Period derived from the German name Kreidezeit, and T is the abbreviation for the Tertiary Period (a historical term for the period of time now covered by the Paleogene and Neogene periods). The event marks the end of the Mesozoic Era and the beginning of the Cenozoic Era. With "Tertiary" being discouraged as a formal time or rock unit by the International Commission on Stratigraphy, the K–T event is now called the Cretaceous–Paleogene (or K–Pg) extinction event by many researchers.

Non-avian dinosaur fossils are found only below the K–T boundary, indicating that non-avian dinosaurs became extinct immediately before, or during the event. A very small number of dinosaur fossils have been found above the K–T boundary, but they have been explained as reworked, that is, fossils that have been eroded from their original locations then preserved in later sedimentary layers. Mosasaurs, plesiosaurs, pterosaurs and many species of plants and invertebrates also became extinct. Mammalian and bird clades passed through the boundary with few extinctions, and evolutionary radiation from those Maastrichtian clades occurred well past the boundary. Rates of extinction and radiation varied across different clades of organisms.

Scientists theorize that the K–T extinctions were caused by one or more catastrophic events, such as massive asteroid impacts (like the Chicxulub impact), or increased volcanic activity. Several impact craters and massive volcanic activity, such as that in the Deccan traps, have been dated to the approximate time of the extinction event. These geological events may have reduced sunlight and hindered photosynthesis, leading to a massive disruption in Earth's ecology. Other researchers believe the extinction was more gradual, resulting from slower changes in sea level or climate. On March 4, 2010, a panel of 41 scientists agreed that the Chicxulub asteroid impact triggered the mass extinction.

Cryptoprocta spelea
Cryptoprocta spelea, also known as the giant fossa, is an extinct species of carnivore from Madagascar in the family Eupleridae, which is most closely related to the mongooses and includes all Malagasy carnivorans. It was first described in 1902, and in 1935 was recognized as a separate species from its closest relative, the living fossa (Cryptoprocta ferox). C. spelea is larger than the fossa, but otherwise similar. The two have not always been accepted as distinct species. When and how the larger form went extinct is unknown; there is some anecdotal evidence, including reports of very large fossas, that there is more than one surviving species.

The species is known from subfossil bones found in a variety of caves in northern, western, southern, and central Madagascar. In some sites, it occurs with remains of C. ferox, but there is no evidence that the two lived at the same time. Living species of comparably-sized, related carnivores in other regions manage to coexist, suggesting that the same may have happened with both C. spelea and C. ferox. C. spelea would have been able to prey on larger animals than its smaller relative could have, including the recently extinct giant lemurs.

Cyathus
Cyathus is a genus of fungi in the Nidulariaceae, a family collectively known as the bird's nest fungi. They are given this name since they resemble tiny bird's nests filled with "eggs", structures large enough to have been mistaken in the past for seeds. However, these are now known to be reproductive structures containing spores. The "eggs", or peridioles, are firmly attached to the inner surface of this fruiting body by an elastic cord of mycelia, which is known as a funiculus. The 45 species are widely distributed throughout the world and some are found in most countries, although a few exist in only one or two locales. Cyathus stercoreus is considered endangered in a number of European countries. Species of Cyathus are also known as splash cups, which refers to the fact that falling raindrops can knock the peridioles out of the open-cup fruiting body. The internal and external surfaces of this cup may be ridged longitudinally (referred to as plicate or striate); this is one example of a taxonomic characteristic that has traditionally served to distinguish between species.

Generally considered inedible, Cyathus species are saprobic, since they obtain nutrients from decomposing organic matter. They usually grow on decaying wood or woody debris, on cow and horse dung, or directly on humus-rich soil. The life cycle of this genus allows it to reproduce both sexually, with meiosis, and asexually via spores. Several Cyathus species produce bioactive compounds, some with medicinal properties, and several lignin-degrading enzymes from the genus may be useful in bioremediation and agriculture. Phylogenetic analysis is providing new insights into the evolutionary relationships between the various species in Cyathus, and has cast doubt on the validity of the older classification systems that are based on traditional taxonomic characteristics.

Daspletosaurus
Daspletosaurus (, meaning 'frightful lizard') is a genus of tyrannosaurid theropod dinosaur that lived in western North America between 77 and 74 million years ago, during the Late Cretaceous Period. Fossils of the only named species (D. torosus) were found in Alberta, although other possible species from Alberta and Montana await description. Including these undescribed species, Daspletosaurus is the most species-rich genus of tyrannosaur.

Daspletosaurus is closely related to the much larger and more recent Tyrannosaurus. Like most known tyrannosaurids, it was a multi-ton bipedal predator equipped with dozens of large, sharp teeth. Daspletosaurus had the small forelimbs typical of tyrannosaurids, although they were proportionately longer than in other genera.

As an apex predator, Daspletosaurus was at the top of the food chain, probably preying on large dinosaurs like the ceratopsid Centrosaurus and the hadrosaur Hypacrosaurus. In some areas, Daspletosaurus coexisted with another tyrannosaurid, Gorgosaurus, though there is some evidence of niche differentiation between the two. While Daspletosaurus fossils are rarer than other tyrannosaurids, the available specimens allow some analysis of the biology of these animals, including social behavior, diet and life history.

Deinosuchus
Deinosuchus is an extinct relative of the alligator that lived 80 to 73 Ma (million years ago), during the Late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek δεινός/deinos ("terrible") and σουχος/soukhos ("crocodile"). The first remains were discovered in North Carolina in the 1850s, but it was not until 1909 that the genus was named and described. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.

Although Deinosuchus was far larger than any modern crocodile or alligator—measuring up to 12 m and weighing up to 8.5 MT—its overall appearance was fairly similar to its smaller relatives. It had large, robust teeth that were built for crushing, and its back was covered with thick semispherical osteoderms. One study indicates that Deinosuchus may have lived for up to 50 years, growing at a similar rate to that of modern crocodilians, but maintaining this growth over a much longer period of time.

Deinosuchus fossils have been found in ten U.S. states, as well as northern Mexico. It lived on both sides of the Western Interior Seaway, and was an opportunistic apex predator in the coastal regions of eastern North America. Deinosuchus reached its largest size in its western habitat, but the eastern populations were far more abundant. Opinion remains divided as to whether these two populations represent separate species. Deinosuchus was probably capable of killing and eating large dinosaurs. It may have also fed upon sea turtles, fish, and other aquatic and terrestrial prey.

Deinonychus
Deinonychus (Greek δεινός, 'terrible' and ὄνυξ, genitive ὄνυχος 'claw') was a genus of carnivorous dromaeosaurid dinosaur. There is one described species, Deinonychus antirrhopus. This 3.4 meter (11 ft) long dinosaur lived during the early Cretaceous Period, about 115-108 million years ago (from the mid-Aptian to early Albian stages). Fossils have been recovered from the U.S. states of Montana, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland.

Paleontologist John Ostrom's study of Deinonychus in the late 1960s revolutionized the way scientists thought about dinosaurs, leading to the "Dinosaur renaissance" and igniting the debate on whether or not dinosaurs were warm-blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal, posture, ratite-like spine, and – especially – the enlarged raptorial claws on the feet, which suggested an active, agile predator.

"Terrible claw" refers to the unusually large, sickle-shaped talon on the second toe of each hind foot. The fossil YPM 5205 preserves a large, strongly curved ungual. In life, archosaurs have a horny sheath over this bone which extends the length. Ostrom looked at crocodile and bird claws and reconstructed the claw for YPM 5205 as over 120 mm long. The species name antirrhopus means “counter balance”, which refers to John Ostrom's idea about the function of the tail. As in other dromaeosaurids, the tail vertebrae have a series of ossified tendons and super-elongated bone processes. These features seemed to make the tail into a stiff counterbalance, but a fossil of the very closely related Velociraptor mongoliensis (IGM 100/986) has an articulated tail skeleton that is curved laterally in a long S–shape. This suggests that, in life, the tail could swish to the sides with a high degree of flexibility.

In both the Cloverly and Antlers Formation, Deinonychus remains have been found closely associated with those of the ornithopod Tenontosaurus. Teeth discovered associated with Tenontosaurus specimens imply it was hunted or at least scavenged upon by Deinonychus.

Delichon
Delichon is a genus of passerine birds that belongs to the swallow family and contains three species named as house martins. These are chunky, bull-headed and short-tailed birds, blackish-blue above with a contrasting white rump, and with white or grey underparts. They have feathering on the toes and tarsi that is characteristic of this genus. The house martins are closely related to other swallows that build mud nests, particularly the Hirundo barn swallows. They breed only in Europe, Asia and the mountains of North Africa. Two species, the Common and Asian House Martins, migrate south in winter, while the Nepal House Martin is resident in the Himalayas year-round.

The house martins nest in colonies on cliffs or buildings, constructing feather- or grass-lined mud nests. The typical clutch is two or three white eggs; both parents build the nest, incubate the eggs and feed the chicks. These martins are aerial hunters of small insects such as flies and aphids. Despite their flying skills the Delichon martins are sometimes caught by fast-flying birds of prey. They may carry fleas or internal parasites. None of the species are considered threatened, although widespread reductions in Common House Martin numbers have been reported from central and northern Europe. This decline is due to factors including poor weather, poisoning by agricultural pesticides, lack of mud for nest building and competition with House Sparrows for nest sites.

Diplodocus
Diplodocus (,, or  ) is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek διπλόος (diploos) "double" and δοκός (dokos) "beam", in reference to its double-beamed chevron bones located in the underside of the tail. These bones were initially believed to be unique to Diplodocus; however, they have since then been discovered in other members of the diplodocid family and in non-diplodocid sauropods such as Mamenchisaurus. It lived in what is now western North America at the end of the Jurassic Period. Diplodocus is one of the more common dinosaur fossils found in the Upper Morrison Formation, a sequence of shallow marine and alluvial sediments deposited about 150 to 147 million years ago, in what is now termed the Kimmeridgian and Tithonian stages. The Morrison Formation records an environment and time dominated by gigantic sauropod dinosaurs such as Camarasaurus, Barosaurus, Apatosaurus and Brachiosaurus.

Diplodocus is among the most easily identifiable dinosaurs, with its classic dinosaur shape, long neck and tail and four sturdy legs. For many years, it was the longest dinosaur known. Its great size may have been a deterrent to the predators Allosaurus and Ceratosaurus: their remains have been found in the same strata, which suggests they coexisted with Diplodocus.

Dinosaurs
Dinosaurs are a diverse group of reptiles. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period (about 230 million years ago) until the end of the Cretaceous period (about 65 million years ago), when the Cretaceous–Tertiary extinction event caused the extinction of most dinosaur species, except for some birds. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, and most paleontologists regard them as the only group of dinosaurs to have survived until the present day.

Dinosaurs are a diverse and varied group of animals; birds, at over 9,000 species, are the most diverse group of vertebrate besides perciform fish. Paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs. Dinosaurs are represented on every continent by both extant species and fossil remains. Some dinosaurs are or were herbivorous, others carnivorous. Some have been bipedal, others quadrupedal, and others have been able to shift between these body postures. Many non-avian species developed elaborate skeletal modifications such as bony armor, horns or crests. Avian dinosaurs have been the planet's dominant flying vertebrate since the extinction of the pterosaurs. Although generally known for the large size of some species, most dinosaurs were human-sized or even smaller. Most groups of dinosaurs are known to have built nests and laid eggs.

The term "dinosaur" was coined in 1842 by the English paleontologist Richard Owen, and derives from Greek δεινός (deinos) "terrible, powerful, wondrous" + σαῦρος (sauros) "lizard". Through the first half of the twentieth century, most of the scientific community mistakenly believed dinosaurs to have been sluggish, unintelligent cold-blooded animals. Most research conducted since the 1970s, however, has indicated that dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction.

Since the first dinosaur fossils were recognized in the early nineteenth century, mounted dinosaur skeletons have been major attractions at museums around the world, and dinosaurs have become a part of world culture. They have been featured in best-selling books and films such as Jurassic Park, and new discoveries are regularly covered by the media. The outdated image of dinosaurs as maladapted extinct monsters has led to the word "dinosaur" entering the vernacular to describe anything that is impractically large, slow-moving, obsolete, or bound for extinction.

Deoxyribonucleic acid
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints, like a recipe or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.

Chemically, DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-parallel. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.

Within cells, DNA is organized into long structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast, prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.

DNA repair
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. Consequently, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages.

The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively repairs damage incurred to its DNA, can enter one of three possible states:
 * 1) an irreversible state of dormancy, known as senescence
 * 2) cell suicide, also known as apoptosis or programmed cell death
 * 3) unregulated cell division, which can lead to the formation of a tumor that is cancerous

The DNA repair ability of a cell is vital to the integrity of its genome and thus to its normal functioning and that of the organism. Many genes that were initially shown to influence life span have turned out to be involved in DNA damage repair and protection. Failure to correct molecular lesions in cells that form gametes can introduce mutations into the genomes of the offspring and thus influence the rate of evolution.

Domestic sheep
Domestic sheep (Ovis aries) are quadrupedal, ruminant mammals typically kept as livestock. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. Although the name "sheep" applies to many species, in everyday usage it almost always refers to Ovis aries. Numbering a little over 1 billion, domestic sheep are the most numerous species in their genus.

Sheep are most likely descended from the wild mouflon of Europe and Asia. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleece, meat (lamb, hogget or mutton) and milk. A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. Ovine meat is called lamb when from younger animals and mutton when from older ones. Sheep continue to be important for wool and meat today, and are also occasionally raised for pelts, as dairy animals, or as model organisms for science.

Sheep husbandry is practised throughout the majority of the inhabited world, and has been fundamental to many civilizations. In the modern era, Australia, New Zealand, the southern and central South American nations, and the British Isles are most closely associated with sheep production.

Sheep-raising has a large lexicon of unique terms which vary considerably by region and dialect. Use of the word sheep began in Middle English as a derivation of the Old English word scēap; it is both the singular and plural name for the animal. A group of sheep is called a flock, herd or mob. Adult female sheep are referred to as ewes, intact males as rams or occasionally tups, castrated males as wethers, and younger sheep as lambs. Many other specific terms for the various life stages of sheep exist, generally related to lambing, shearing, and age.

Being a key animal in the history of farming, sheep have a deeply entrenched place in human culture, and find representation in much modern language and symbology. As livestock, sheep are most-often associated with pastoral, Arcadian imagery. Sheep figure in many mythologies—such as the Golden Fleece—and major religions, especially the Abrahamic traditions. In both ancient and modern religious ritual, sheep are used as sacrificial animals.

Drosera regia
Drosera regia, commonly known as the king sundew, is a carnivorous plant in the sundew genus Drosera and is endemic to a single valley in South Africa. The genus name Drosera comes from the Greek word droseros, meaning "dew-covered". The specific epithet regia is derived from the Latin for "royal", a reference to the "striking appearance" of the species. Individual leaves can reach 70 cm in length. It has many unusual relict characteristics not found in most other Drosera species, including woody rhizomes, operculate pollen, and the lack of circinate vernation in scape growth. All of these factors, combined with molecular data from phylogenetic analysis, contribute to the evidence that D. regia possesses some of the most ancient characteristics within the genus. Some of these are shared with the related Venus flytrap (Dionaea muscipula), which suggests a close evolutionary relationship.

The tentacle-covered leaves can capture large prey, such as beetles, moths, and butterflies. The tentacles of all Drosera species are specialised stalked glands on the leaf's upper surface that produce a sticky mucilage. The leaves are considered active flypaper traps that respond to captured prey by bending to surround it. In its native fynbos habitat, the plants compete for space with native marsh grasses and low evergreen shrubs. Of the two known populations of D. regia, the higher altitude site appears to be overgrown and is essentially extirpated. The lower altitude site is estimated to have about 50 mature plants, making it the most endangered Drosera species, since it is threatened with extinction in the wild. It is often cultivated by carnivorous plant enthusiasts and a single cultivar has been registered.

Ediacara
The Ediacara (, formerly Vendian) biota consisted of enigmatic tubular and frond-shaped, mostly sessile (stationary) organisms which lived during the Ediacaran Period (ca. 635-542 Ma). Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The Ediacara biota first appeared as the Earth thawed from the Cryogenian period's extensive glaciation, and largely disappeared contemporaneous with the rapid appearance of biodiversity known as the Cambrian explosion. Most currently existing body-plans of animals made first appearances in the fossil record of the Cambrian. For macroorganisms, the Cambrian biota completely replaced the organisms that populated the Ediacaran fossil record.

The organisms of the Ediacaran Period first appeared around and flourished until the cusp of the Cambrian  when the characteristic communities of fossils vanished. While rare fossils that may represent survivors have been found as late as the Middle Cambrian (510 to 500 million years ago) the earlier fossil communities disappear from the record at the end of the Ediacaran leaving only curious fragments of once-thriving ecosystems. Multiple hypotheses exist to explain the disappearance of this biota, including preservation bias, a changing environment, the advent of predators and competition from other life-forms.

Determining where Ediacaran organisms fit in the tree of life has proven impossible. The morphology and habit of some taxa (e.g. Funisia dorothea) suggest relationships to Porifera or Cnidaria.  Kimberella may show a similarity to molluscs, and other organisms have been thought to possess bilateral symmetry, though this is controversial. Most macroscopic fossils are morphologically distinct from later life-forms: they resemble discs, tubes, mud-filled bags or quilted mattresses. Due to the difficulty of deducing evolutionary relationships among these organisms some paleontologists have suggested that these represent completely extinct lineages that do not resemble any living organism. One paleontologist proposed a separate kingdom level category Vendozoa (now renamed Vendobionta) in the Linnaean hierarchy for the Ediacaran biota. If these enigmatic organisms left no descendants their strange forms might be seen as a "failed experiment" in multicellular life with later multicellular life independently evolving from unrelated single-celled organisms.

Edmontosaurus
Edmontosaurus is a genus of crestless duck-billed dinosaur. The fossils of this animal have been found in rocks of western North America that date from the late Campanian stage to the end of the Maastrichtian stage of the Cretaceous Period, between 73 and 65.5 million years ago. It was one of the last non-avian dinosaurs, and lived alongside Triceratops and Tyrannosaurus shortly before the Cretaceous–Tertiary extinction event.

Edmontosaurus was one of the largest hadrosaurids, measuring up to 13 m long and weighing around 4.0 MT. It is known from several well-preserved specimens that include not only bones, but in some cases extensive skin impressions and possible gut contents. It is classified as a hadrosaurine hadrosaurid (those hadrosaurids which lacked a hollow crest), and was closely related to Anatotitan, if not a synonym.

Edmontosaurus has a lengthy and complicated taxonomic history dating to the late 19th century. Various species classified with genera such as Claosaurus, Thespesius, Trachodon, and the well-known but now defunct genus Anatosaurus are now regarded as belonging to Edmontosaurus. The first fossils named Edmontosaurus were discovered in southern Alberta, Canada, in what used to be called the lower Edmonton Formation. The type species, E. regalis, was named by Lawrence Lambe in 1917, although several other species that are now classified in Edmontosaurus were named earlier. The best known of these is E. annectens, originally named by Othniel Charles Marsh in 1892 as Claosaurus annectens and known for many years as Anatosaurus annectens. A third smaller species, E. saskatchewanensis, is also known. The name Edmontosaurus means "Edmonton lizard"; the genus was named after the Edmonton Formation, now known as the Horseshoe Canyon Formation.

Edmontosaurus was widely distributed across western North America. The distribution of Edmontosaurus fossils suggests that it preferred coasts and coastal plains. It was an herbivore that could move on both two legs and four. Because it is known from several bone beds, Edmontosaurus is thought to have lived in groups, and may have been migratory as well. The wealth of fossils has allowed researchers to study its paleobiology in detail, including its brain, how it may have fed, and its injuries and pathologies, such as evidence for a tyrannosaur attack on one edmontosaur specimen.

Elfin-woods Warbler
The Elfin-woods Warbler (Dendroica angelae), or Reinita de Bosque Enano (Spanish name), is a bird endemic to the Caribbean island of Puerto Rico where it is a local and uncommon species. Discovered in 1968 and described in 1972, it is the most recently described species of New World warbler (Parulidae family). The species name, angelae, is a tribute to Angela Kepler, one of its discoverers. An insectivore, it feeds by gleaning small insects off leaves.

Due to its small populations and restricted habitats, conservation efforts were begun in 1982 to protect this species but, as of 2005, the warbler was still in need of protection. The species is not in immediate danger as the majority of its habitat is protected forest, but introduced species, such as rats and Small Asian Mongooses, habitat reduction, and natural disasters represent potential threats to the population.

Elk
The elk, or wapiti (Cervus canadensis), is one of the largest species of deer in the world and one of the largest mammals in North America and eastern Asia. In the deer family (Cervidae), only the moose, Alces alces (called an "elk" in Europe), is larger, and Cervus unicolor (the sambar deer) can rival the C. canadensis elk in size. Elk are almost identical to red deer found in Europe, of which they were long believed to be a subspecies; however, mitochondrial DNA evidence from 2004 strongly suggests they are a distinct species.

Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves, and bark. Although native to North America and eastern Asia, they have adapted well to countries where they have been introduced, including New Zealand, Australia and Argentina. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced.

Male elk have large antlers which are shed each year. Males engage in ritualized mating behaviors during the rut, including posturing, antler wrestling (sparring), and bugling, a loud series of vocalizations which establishes dominance over other males and attracts females.

Elk are susceptible to a number of infectious diseases, some of which can be transmitted to livestock. Efforts to eliminate infectious diseases from elk populations, largely through vaccination, have had mixed success.

Some cultures revere the elk as a spiritual force. In parts of Asia, antlers and their velvet are used in traditional medicines. Elk are hunted as a game species; the meat is leaner and higher in protein than beef or chicken.

Emperor Penguin
The Emperor Penguin (Aptenodytes forsteri) is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching 122 cm in height and weighing anywhere from 22 to 45 kg. The dorsal side and head are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches. Like all penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat.

Its diet consists primarily of fish, but can also include crustaceans, such as krill, and cephalopods, such as squid. In hunting, the species can remain submerged up to 18 minutes, diving to a depth of 535 m. It has several adaptations to facilitate this, including an unusually structured hemoglobin to allow it to function at low oxygen levels, solid bones to reduce barotrauma, and the ability to reduce its metabolism and shut down non-essential organ functions.

The Emperor Penguin is perhaps best known for the sequence of journeys adults make each year in order to mate and to feed their offspring. The only penguin species that breeds during the Antarctic winter, it treks 50 – over the ice to breeding colonies which may include thousands of individuals. The female lays a single egg, which is incubated by the male while the female returns to the sea to feed; parents subsequently take turns foraging at sea and caring for their chick in the colony. The lifespan is typically 20 years in the wild, although observations suggest that some individuals may live to 50 years of age.

Emu
The Emu, Dromaius novaehollandiae, is the largest bird native to Australia and the only extant member of the genus Dromaius. It is also the second-largest extant bird in the world by height, after its ratite relative, the ostrich. The soft-feathered, brown, flightless birds reach up to 2 m in height. The Emu is common over most of mainland Australia, although it avoids heavily populated areas, dense forest, and arid areas. Emus can travel great distances at a fast, economical trot and, if necessary, can sprint at 50 km/h (31 mph) for some distance at a time. They are opportunistically nomadic and may travel long distances to find food; they feed on a variety of plants and insects, but have been known to go weeks without food. Emus will sit in water and are also able to swim.

The Emu subspecies that previously inhabited Tasmania became extinct after the European settlement of Australia in 1788; and the distribution of the mainland subspecies has been influenced by human activities. Once common on the east coast, Emu are now uncommon; by contrast, the development of agriculture and the provision of water for stock in the interior of the continent have increased the range of the Emu in arid regions. Emus are farmed for their meat, oil, and leather.

Eremoryzomys polius
Eremoryzomys polius, also known as the Gray Rice Rat or the Marañon Oryzomys, is a rodent in the tribe Oryzomyini of the family Cricetidae. Discovered in 1912 and first described in 1913 by Wilfred Osgood, it was originally placed in Oryzomys and named Oryzomys polius. In 2006, a cladistic analysis found that it was not closely related to Oryzomys in the strict sense or to any other oryzomyine, so that it is now placed in its own genus, Eremoryzomys. Eremoryzomys has a limited distribution in the dry upper valley of the Marañón River in central Peru, but may yet contain more than one species.

A large, long-tailed rice rat, with head and body length of 138 to 164 mm (5.4 to 6.5 in), Eremoryzomys polius has gray fur and short ears. There are well-developed ungual tufts of hair on the hindfeet. Females have eight mammae. The rostrum (front part of the skull) is long and robust and the braincase is rounded. The bony palate is relatively short. The IUCN assesses the conservation status of the species as "Data Deficient"; it is poorly known but may be threatened by habitat destruction.

Eurasian Crag Martin
The Eurasian Crag Martin or just Crag Martin, Ptyonoprogne rupestris, is a small passerine bird in the swallow family. It is about 14 cm (5.5 in) long with ash-brown upperparts and paler underparts, and a short, square tail that has distinctive white patches on most of its feathers. It breeds in the mountains of southern Europe, northwestern Africa and southern Asia. It can be confused with the other two species in its genus, but is larger than both, with brighter tail spots and different plumage tone. Many European birds are resident, but some northern populations and most Asian breeders are migratory, wintering in northern Africa, the Middle East or India.

The Eurasian Crag Martin builds a nest adherent to the rock under a cliff overhang or increasingly onto a man-made structure. It makes a neat half-cup mud nest with an inner soft lining of feathers and dry grass. Nests are often solitary, although a few pairs may breed relativity close together at good locations. Two to five brown-blotched white eggs are incubated mainly by the female, and both parents feed the chicks. This species does not form large breeding colonies, but is gregarious outside the breeding season. It feeds on a wide variety of insects that are caught in its beak as the martin flies near to cliff faces or over streams and alpine meadows. Adults and young may be hunted and eaten by birds of prey or corvids, and this species is a host of blood-sucking mites. With its very large and expanding range and large population there are no significant conservation concerns.

This bird is closely related to the other two crag martins which share its genus, and has sometimes been considered to be the same species as one or both, although it appears that there are areas where two species' ranges overlap without hybridisation occurring. All three Ptyonoprogne crag martins are quite similar in behaviour to other Old World swallows that build mud nests, and are sometimes subsumed into the larger genus Hirundo, but this approach leads to inconsistencies in classifying other genera, particularly the house martins.

Eurasian Tree Sparrow
The Eurasian Tree Sparrow, Passer montanus, is a passerine bird in the sparrow family with a rich chestnut crown and nape, and a black patch on each pure white cheek. The sexes are similarly plumaged, and young birds are a duller version of the adult. This sparrow breeds over most of temperate Eurasia and Southeast Asia, where it is known as the Tree Sparrow, and it has been introduced elsewhere including the United States, where it is known as the Eurasian Tree Sparrow or German Sparrow to differentiate it from the native unrelated American Tree Sparrow. Although several subspecies are recognised, the appearance of this bird varies little across its extensive range.

The Eurasian Tree Sparrow's untidy nest is built in a natural cavity, a hole in a building or the large nest of a magpie or stork. The typical clutch is five or six eggs which hatch in under two weeks. This sparrow feeds mainly on seeds, but invertebrates are also consumed, particularly during the breeding season. As with other small birds, infection by parasites and diseases, and predation by birds of prey take their toll, and the typical life span is about two years.

The Eurasian Tree Sparrow is widespread in the towns and cities of eastern Asia, but in Europe it is a bird of lightly wooded open countryside, with the House Sparrow breeding in the more urban areas. The Eurasian Tree Sparrow's extensive range and large population ensure that it is not endangered globally, but there have been large declines in western European populations, in part due to changes in farming practices involving increased use of herbicides and loss of winter stubble fields. In eastern Asia and western Australia, this species is sometimes viewed as a pest, although it is also widely celebrated in oriental art.

Eurasian Treecreeper
The Eurasian Treecreeper or Common Treecreeper, Certhia familiaris, is a small passerine bird also known in the British Isles, where it is the only living member of its genus, simply as Treecreeper. It is similar to other treecreepers, and has a curved bill, patterned brown upperparts, whitish underparts, and long stiff tail feathers which help it creep up tree trunks. It can be most easily distinguished from the similar Short-toed Treecreeper, which shares much of its European range, by its different song.

The Eurasian Treecreeper has nine or more subspecies which breed in different parts of its range in temperate Eurasia. This species is found in woodlands of all kinds, but where it overlaps with the Short-toed Treecreeper in western Europe it is more likely to be found in coniferous forests or at higher altitudes. It nests in tree crevices or behind bark flakes, and favours introduced Giant Sequoia as nest sites where they are available. The female typically lays five or six pink-speckled white eggs in the lined nest, but eggs and chicks are vulnerable to attack by woodpeckers and mammals, including squirrels.

The Eurasian Treecreeper is insectivorous and climbs up tree trunks like a mouse, to search for insects which it picks from crevices in the bark with its fine curved bill. It then flies to the base of another tree with a distinctive erratic flight. This bird is solitary in winter, but may form communal roosts in cold weather.

Evolution
Evolution is the change in the inherited traits of a population of organisms through successive generations. After a population splits into smaller groups, these groups evolve independently and may eventually diversify into new species. Ultimately, life is descended from a common ancestry through a long series of these speciation events, stretching back in a tree of life that has grown over the 3.5 billion years of life on Earth. This is visible in anatomical, genetic and other likenesses between groups of organisms, geographical distribution of related species, the fossil record and the recorded genetic changes in living organisms over many generations. To distinguish from other uses of the word evolution, it is sometimes termed biological evolution, genetic evolution or organic evolution.

Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. A trait is a particular characteristic, such as eye color, height, or a behavior, that is expressed when an organism's genes interact with its environment. Genes vary within populations, so organisms show heritable differences (variation) in their traits. The main cause of variation is mutation, which changes the sequence of a gene. Altered genes, or alleles, are then inherited by offspring. There can sometimes also be transfer of genes between species.

Two main processes cause variants to become more common or rare in a population. One is natural selection, through which traits that aid survival and reproduction become more common, while traits that hinder survival and reproduction become more rare. Natural selection occurs because only a few individuals in each generation will survive, since resources are limited and organisms produce many more offspring than their environment can support. Over many generations, mutations produce successive, small, random changes in traits, which are then filtered by natural selection and the beneficial changes retained. This adjusts traits so they become suited to an organism's environment: these adjustments are called adaptations. Not every trait, however, is an adaptation. Another cause of evolution is genetic drift, which produces entirely random changes in how common traits are in a population. Genetic drift comes from the role that chance plays in whether a trait will be passed on to the next generation.

Evolutionary biologists document the fact that evolution occurs, and also develop and test theories that explain its causes. The study of evolutionary biology began in the mid-nineteenth century, when research into the fossil record and the diversity of living organisms convinced most scientists that species changed over time. The mechanism driving these changes remained unclear until the theories of natural selection were independently proposed by Charles Darwin and Alfred Wallace. In 1859, Darwin's seminal work On the Origin of Species brought the new theories of evolution by natural selection to a wide audience, leading to the overwhelming acceptance of evolution among scientists. In the 1930s, Darwinian natural selection became understood in combination with Mendelian inheritance, forming the modern evolutionary synthesis, which connected the units of evolution (genes) and the mechanism of evolution (natural selection). This powerful explanatory and predictive theory has become the central organizing principle of modern biology, directing research and providing a unifying explanation for the history and diversity of life on Earth. Evolution is therefore applied and studied in fields as diverse as agriculture, anthropology, conservation biology, ecology, medicine, paleontology, philosophy, and psychology along with other specific topics in the previous listed fields.

Exosome complex
The exosome complex (or PM/Scl complex, often just called the exosome) is a multi-protein complex capable of degrading various types of RNA (ribonucleic acid) molecules. Exosome complexes are found in both eukaryotic cells and archaea, while in bacteria a simpler complex called the degradosome carries out similar functions.

The core of the exosome contains a six-membered ring structure to which other proteins are attached. In eukaryotic cells, the exosome complex is present in the cytoplasm, nucleus and especially the nucleolus, although different proteins interact with the exosome complex in these compartments regulating the RNA degradation activity of the complex to substrates specific to these cell compartments. Substrates of the exosome include messenger RNA, ribosomal RNA, and many species of small RNAs. The exosome has an exoribonucleolytic function, meaning it degrades RNA starting at one end (the so-called 3′ end in this case), rather than cleaving the RNA at specific sites within the molecule.

Although no causative relation between the exosome complex and any disease is known, several proteins in the exosome are the target of autoantibodies in patients with specific autoimmune diseases (especially the PM/Scl overlap syndrome) and some antimetabolitic chemotherapies for cancer function by blocking the activity of the exosome.

Ficus aurea
Ficus aurea, commonly known as the Florida strangler fig (or simply strangler fig), golden fig, or higuerón, is a tree in the family Moraceae that is native to Florida, the northern and western Caribbean, southern Mexico and Central America south to Panama. The specific epithet aurea was coined by English botanist Thomas Nuttall who described the species in 1846; older names applied to this species have been ruled invalid.

Ficus aurea is a strangler fig; seed germination usually takes place in the canopy of a host tree and the seedling lives as an epiphyte until its roots establish contact with the ground. It then enlarges and strangles its host, eventually becoming a freestanding tree in its own right. Individuals may reach 30 m (100 ft) in height. Like all figs, it has an obligate mutualism with fig wasps; figs are only pollinated by fig wasps, and fig wasps can only reproduce in fig flowers. The tree provides habitat, food and shelter for a host of tropical lifeforms including epiphytes in cloud forests and birds, mammals, reptiles and invertebrates. F. aurea is used in traditional medicine, for live fencing, as an ornamental and as a bonsai.

Fin whale
The fin whale (Balaenoptera physalus), also called the finback whale, razorback, or common rorqual, is a marine mammal belonging to the suborder of baleen whales. It is the second largest whale and the second largest living animal after the blue whale, growing to nearly 27 meters (88 ft) long.

Long and slender, the fin whale's body is brownish-grey with a paler underside. There are at least two distinct subspecies: the Northern fin whale of the North Atlantic, and the larger Antarctic fin whale of the Southern Ocean. It is found in all the world's major oceans, from polar to tropical waters. It is absent only from waters close to the ice pack at both the north and south poles and relatively small areas of water away from the open ocean. The highest population density occurs in temperate and cool waters. Its food consists of small schooling fish, squid, and crustaceans including mysids and krill.

Like all other large whales, the fin whale was heavily hunted during the twentieth century and is an endangered species. Almost 750,000 fin whales were taken from the Southern Hemisphere alone between 1904 and 1979 and less than 3,000 currently remain in that region. The International Whaling Commission (IWC) has issued a moratorium on commercial hunting of this whale, although Iceland and Japan have resumed hunting: in 2009, Iceland took 125 fin whales during its whaling season, and Japan took 1 fin whale in its 2008-2009 Antarctic season. The species is also hunted by Greenlanders under the Aboriginal Subsistence Whaling provisions of the IWC. Collisions with ships and noise from human activity also significantly threaten recovery.

Flight feathers
Flight feathers are the long, stiff, asymmetrically shaped, but symmetrically paired feathers on the wings or tail of a bird; those on the wings are called remiges (singular remex) while those on the tail are called rectrices (singular rectrix). Their primary function is to aid in the generation of both thrust and lift, thereby enabling flight. The flight feathers of some birds have evolved to perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on the leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer. Even flightless birds still retain flight feathers, though sometimes in radically modified forms.

The moult of their flight feathers can cause serious problems for birds, as it can impair their ability to fly. Different species have evolved different strategies for coping with this, ranging from dropping all their flight feathers at once (and thus becoming flightless for some relatively short period of time) to extending the moult over a period of several years.

Flocke
Flocke is a female polar bear who was born in captivity at the Nuremberg Zoo in Nuremberg, Germany on 11 December 2007. A few weeks after her birth, she was removed from her mother's care after concerns were raised for her safety. Although the zoo had established a strict non-interference policy with its animals, officials chose to raise the cub by hand. This decision came at a time when the zoo was receiving negative attention from the media after another female polar bear reportedly ate her newly born cubs.

Like Knut, a captive-born and handraised polar bear at the Berlin Zoo, Flocke ("flake" in German) quickly became a media sensation. After she made her debut to the public on 8 April 2008, her name was trademarked by the zoo and her image appeared on toys and in advertisements throughout the city. The zoo announced in May 2008 that United Nations Environment Program chief Achim Steiner would be Flocke's official patron with the hope of using the bear as an ambassador to encourage awareness of climate change. In late 2008, a Russian-born male polar bear named Rasputin was introduced to Flocke's enclosure in the hopes that she would gain valuable socializing skills with a member of her own species. In April 2010, both bears were relocated to Marineland in southern France.

Fossa
The fossa (Cryptoprocta ferox) ( or ) is a cat-like, carnivorous mammal that is endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family (Herpestidae). Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a close relationship with viverrids (most civets and their relatives). Its classification, along with that of the other Malagasy carnivores, influenced hypotheses about how many times mammalian carnivores have colonized the island. With genetic studies demonstrating that the fossa and all other Malagasy carnivores are most closely related to each other (forming a clade, recognized as the family Eupleridae), carnivores are now thought to have colonized the island once around 18 to 20 million years ago.

The fossa is the largest mammalian carnivore on the island of Madagascar and has been compared to a small cougar. Adults have a head-body length of 70 - 80 cm and weigh between 5.5 - 8.6 kg, with the males larger than the females. It has semi-retractable claws and flexible ankles that allow it to climb up and down trees head-first, and also support jumping from tree-to-tree. The fossa is unique within its family for the shape of its genitalia, which share traits with those of cats and hyenas.

The species is widespread, although population densities are usually low. It is found solely in forested habitat, and actively hunts both day and night. Over 50% of its diet consists of lemurs, the endemic primates found on the island, though tenrecs, rodents, lizards, birds, and other animals are also documented as prey. Mating usually occurs in trees on horizontal limbs and can last for several hours. Litters range from one to six pups, which are born blind and toothless (altricial). Infants wean after 4.5 months and are independent after a year. Sexual maturity occurs around three to four years of age, and life expectancy in captivity is 20 years. The fossa is listed as "Vulnerable" by the International Union for Conservation of Nature (IUCN). It is generally feared by the Malagasy people and is often protected by their taboo, known as fady. The greatest threat to the species is habitat destruction.

Fungus
A fungus (pl. fungi)) is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi ( or ), that is separate from plants, animals and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (a monophyletic group). This fungal group is distinct from the structurally similar slime molds (myxomycetes) and water molds (oomycetes). The discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants.

Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, and their cryptic lifestyles in soil, on dead matter, and as symbionts of plants, animals, or other fungi. They may become noticeable when fruiting, either as mushrooms or molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange. They have long been used as a direct source of food, such as mushrooms and truffles, as a leavening agent for bread, and in fermentation of various food products, such as wine, beer, and soy sauce. Since the 1940s, fungi have been used for the production of antibiotics, and, more recently, various enzymes produced by fungi are used industrially and in detergents. Fungi are also used as biological agents to control weeds and pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals including humans. The fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies. Fungi can break down manufactured materials and buildings, and become significant pathogens of humans and other animals. Losses of crops due to fungal diseases (e.g. rice blast disease) or food spoilage can have a large impact on human food supplies and local economies.

The fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, and morphologies ranging from single-celled aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of Kingdom Fungi, which has been estimated at around 1.5 million species, with about 5% of these having been formally classified. Ever since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christian Hendrik Persoon, and Elias Magnus Fries, fungi have been classified according to their morphology (e.g., characteristics such as spore color or microscopic features) or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits. Phylogenetic studies published in the last decade have helped reshape the classification of Kingdom Fungi, which is divided into one subkingdom, seven phyla, and ten subphyla.

Galerina marginata
Galerina marginata is a species of poisonous fungus in the Hymenogastraceae family of the Agaricales order. Prior to 2001, the species G. autumnalis, G. oregonensis, G. unicolor, and G. venenata were thought to be separate due to differences in habitat and the viscidity of their caps, but phylogenetic analysis showed that they are all the same species.

The fruit bodies have brown to yellow-brown caps that fade in color when drying. The gills are brownish and give a rusty spore print. A well-defined membranous ring is typically seen on the stems of young specimens but often disappears with age. In older fruit bodies, the caps are flatter and the gills and stems browner. The species is a classic "little brown mushroom"—a catchall category that includes all small to medium-sized, hard-to-identify brownish mushrooms, and may be easily confused with several edible species.

Galerina marginata is widespread in the Northern Hemisphere, including Europe, North America and Asia, and has also been found in Australia. It is a wood-rotting fungus that grows predominantly on decaying conifer wood. An extremely poisonous species, it contains the same deadly amatoxins found in the death cap (Amanita phalloides). Ingestion in toxic amounts causes severe liver damage with vomiting, diarrhea, hypothermia, and eventual death if not treated rapidly. About ten poisonings have been attributed to the species now grouped as G. marginata over the last century.

Genetics
Genetics (from Ancient Greek γενετικός genetikos, “genitive” and that from γένεσις genesis, “origin”  ), a discipline of biology, is the science of heredity and variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the process of inheritance, only began with the work of Gregor Mendel in the mid-nineteenth century. Although he did not know the physical basis for heredity, Mendel observed that organisms inherit traits via discrete units of inheritance, which are now called genes.

Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides—the sequence of these nucleotides is the genetic information organisms inherit. DNA naturally occurs in a double stranded form, with nucleotides on each strand complementary to each other. Each strand can act as a template for creating a new partner strand—this is the physical method for making copies of genes that can be inherited.

The sequence of nucleotides in a gene is translated by cells to produce a chain of amino acids, creating proteins—the order of amino acids in a protein corresponds to the order of nucleotides in the gene. This relationship between nucleotide sequence and amino acid sequence is known as the genetic code. The amino acids in a protein determine how it folds into a three-dimensional shape; this structure is, in turn, responsible for the protein's function. Proteins carry out almost all the functions needed for cells to live. A change to the DNA in a gene can change a protein's amino acids, changing its shape and function: this can have a dramatic effect in the cell and on the organism as a whole.

Although genetics plays a large role in the appearance and behavior of organisms, it is the combination of genetics with what an organism experiences that determines the ultimate outcome. For example, while genes play a role in determining an organism's size, the nutrition and other conditions it experiences after inception also have a large effect.

Geastrum triplex
Geastrum triplex, commonly known as the collared earthstar, the saucered earthstar, or the triple earthstar, is an inedible species of fungus belonging to the genus Geastrum, or earthstar fungi. First described in 1840 as Geaster triplex, several authors have suggested that Geastrum indicum, described in 1832, is the legitimate name for the species. Immature fruit bodies are spherical—somewhat resembling puffballs with pointed beaks—and are partially or completely buried in the ground. As the fungus matures, the outer layer of tissue (the exoperidium) splits into four to eight pointed segments which spread outwards and downwards, lifting and exposing the spherical inner spore sac. The spore sac contains gleba, a mass of spores and fertile mycelial tissue that when young is white and firm, but ages to becomes brown and powdery. Often, a layer of the exoperidium splits around the perimeter of the spore sac so that it appears to rest in a collar or saucer. Atop the spore sac is a small pointed beak, the peristome, which has a small hole from which spores may be released. The species is the largest of the earthstar fungi, with a tip to tip length of an expanded mature specimen reaching up to 12 cm.

Geastrum triplex is a common and widespread species found in the detritus and leaf litter of hardwood forests in many parts of the world, including Asia, Australasia, Europe, and both North and South America. Fruit bodies have been analyzed chemically to determine their lipid content, and various chemical derivatives of the fungal sterol ergosterol have been identified. The fungus has a history of use in the traditional medicines of native North America and China.

Giant Otter


The Giant Otter (Pteronura brasiliensis) is a South American carnivorous mammal. It is the longest member of the Mustelidae, or weasel family, a globally successful group of predators. Unusually for a mustelid, the Giant Otter is a social species, with family groups typically supporting three to eight members. The groups are centered on a dominant breeding pair and are extremely cohesive and cooperative. Although generally peaceful, the species is territorial and aggression has been observed between groups. The Giant Otter is diurnal, being active exclusively during daylight hours. It is the noisiest otter species and distinct vocalizations have been documented that indicate alarm, aggressiveness, and reassurance. The Giant Otter ranges across north-central South America. The Giant Otter lives mostly in and along the Amazon River and in the Pantanal.

Its distribution has been greatly reduced and is now discontinuous. Decades of poaching for its velvety pelt, peaking in the 1950s and 1960s, hugely diminished population numbers. The species was listed as endangered in 1999 and population estimates are typically below 5,000 in the wild. The Guianas are the last real stronghold for the species. It is the most endangered mammal in the neo-tropics. Habitat degradation and loss is the greatest current threat. The Giant Otter is also rare in captivity: as of 2003, only 60 animals were held.

The Giant Otter shows a variety of adaptations suitable to an amphibious lifestyle, including exceptionally dense fur, a wing-like tail, and webbed feet. The species prefers freshwater rivers and streams, which are usually seasonally flooded, and may also take to freshwater lakes and springs. It constructs extensive campsites close to feeding areas, clearing large amounts of vegetation. The Giant Otter largely subsists on a diet of fish, particularly characins and catfish, and may also eat crabs. It has no serious natural predators other than humans, although it must compete with other species, including the Neotropical Otter and caiman species, for food resources.

Golden-crowned Sifaka
The Golden-crowned Sifaka or Tattersall's Sifaka (Propithecus tattersalli) is a medium-sized lemur characterized by mostly white fur, prominent furry ears and a golden-orange crown. It is one of the smallest sifakas (genus Propithecus), weighing around 3.5 kg and measuring approximately 90 cm from head to tail. Like all sifakas, it is a vertical clinger and leaper, and its diet includes mostly seeds and leaves. The Golden-crowned Sifaka is named after its discoverer, Ian Tattersall, who first spotted the species in 1974. However, it was not formally described until 1988, after a research team led by Elwyn Simons observed and captured some specimens for captive breeding. The Golden-crowned Sifaka most closely resembles the western forest sifakas of the P. verreauxi group, yet its karyotype suggests a closer relationship with the P. diadema group of eastern forest sifakas. Despite the similarities with both groups, more recent studies of its karyotype support its classification as a distinct species.

Found in gallery, deciduous, and semi-evergreen forest, its restricted range includes 44 forest fragments, totaling an area of 44,125 ha, centered around the town of Daraina in northeast Madagascar. Its estimated population is between 6,000 and 10,000 individuals. It is primarily active during the day, although it also tends to be active at dawn and dusk during the rainy season. It sleeps in tall emergent trees, and is preyed upon by the Fossa. The Golden-crowned Sifaka lives in groups of around five to six individuals, with groups containing a balanced number of adult males and females. Scent is used to mark territories, which are defended by growling, chasing, and ritualistic leaping displays. Reproduction is seasonal, with gestation lasting six months and lactation lasting five months. Infants are weaned during the wet season to ensure the best chances of survival.

The small range and fragmented populations of this species weigh heavily on its survival. Forest fragmentation, habitat destruction, poaching, slash-and-burn agriculture, and other human factors threaten its existence. The Golden-crowned Sifaka is listed by the IUCN Red List as Endangered. Its range was originally not covered by any national parks or protected areas in Madagascar, but a new protected area was established in 2005 to include a 20,000 ha portion. Attempts have been made to keep the Golden-crowned Sifaka in captivity at the Duke Lemur Center in Durham, North Carolina. The small colony was maintained from 1988 to 2008. In Madagascar, lawlessness resulting from the 2009 political coup led to increased poaching of this species, and many were sold to local restaurants as a delicacy.

Golden White-eye
The Golden White-eye (Cleptornis marchei) is a species of bird in the white-eye family Zosteropidae. It is the only species within the genus Cleptornis. The Golden White-eye was once considered to be a honeyeater in the family Meliphagidae and although it is now known to be a white-eye, its position within that family is still uncertain. The species is restricted to the islands of Saipan and Aguijan in the Northern Mariana Islands, where it is sympatric (shares its range) and competes with the related Bridled White-eye. The Golden White-eye has golden plumage and a pale eye-ring. It feeds on insects, fruit, and nectar and forages in pairs or small family groups. The bird is monogamous and lays two eggs in a small cup nest.

Fossil evidence shows the Golden White-eye once also occurred on Tinian and Rota but was extirpated in those locations through the impact of human activities. Despite its current abundance on Saipan and Aguijan, and the fact that it has among the highest recorded densities for any bird, it is nevertheless considered to be critically endangered. It is threatened by the invasive Brown Tree Snake, which has recently become established on Saipan, and this predator is expected to cause a rapid decline in the population if not controlled. Efforts are under way to control the snakes and breed the white-eye in zoos.

Gorgosaurus
Gorgosaurus (, meaning "fierce lizard") is a genus of tyrannosaurid theropod dinosaur that lived in western North America during the Late Cretaceous Period, between about 76.5 and 75 million years ago. Fossil remains have been found in the Canadian province of Alberta and possibly the U.S. state of Montana. Paleontologists recognize only the type species, G. libratus, although other species have been erroneously referred to the genus.

Like most known tyrannosaurids, Gorgosaurus was a bipedal predator weighing more than a metric ton as an adult; dozens of large, sharp teeth lined its jaws, while its two-fingered forelimbs were comparatively small. Gorgosaurus was most closely related to Albertosaurus, and more distantly related to the larger Tyrannosaurus. Gorgosaurus and Albertosaurus are extremely similar, distinguished mainly by subtle differences in the teeth and skull bones. Some experts consider G. libratus to be a species of Albertosaurus; this would make Gorgosaurus a junior synonym of that genus.

Gorgosaurus lived in a lush floodplain environment along the edge of an inland sea. An apex predator, it was at the top of the food chain, preying upon abundant ceratopsids and hadrosaurs. In some areas, Gorgosaurus coexisted with another tyrannosaurid, Daspletosaurus. Though these animals were roughly the same size, there is some evidence of niche differentiation between the two. Gorgosaurus is the best-represented tyrannosaurid in the fossil record, known from dozens of specimens. These plentiful remains have allowed scientists to investigate its ontogeny, life history and other aspects of its biology.

Gray Mouse Lemur
The Gray Mouse Lemur (Microcebus murinus) is a small lemur, a type of strepsirrhine primate, found only on the island of Madagascar. Weighing 58 to 67 g, it is the largest of the mouse lemurs (genus Microcebus), a group which include the smallest primates in the world. The species is named for its mouse-like size and coloration and is known locally (in Malagasy) as Tsidy, Koitsiky, Titilivaha, Pondiky, and Vakiandry. Nearly indistinguishable from each other by appearance, the Gray Mouse Lemur and all other mouse lemurs are considered cryptic species. For this reason, the Gray Mouse Lemur was considered the only mouse lemur species for decades until more recent studies began to distinguish between the species.

Like all mouse lemurs, this species is nocturnal and arboreal. It is very active, and although it forages alone, groups of males and females will form sleeping groups and share tree holes during the day. It exhibits a form of dormancy called torpor during the cool, dry winter months, and in some cases undergoes seasonal torpor (or hibernation), which is unusual for primates. The Gray Mouse Lemur can be found in several types of forest throughout western and southern Madagascar. Its diet consists primarily of fruit, insects, flowers, and nectar. In the wild, its natural predators include owls, snakes, and endemic mammalian predators. Predation pressure is higher for this species than among any other primate species, with one out of four individuals taken by a predator each year. This is counterbalanced by its high reproductive rate. Breeding is seasonal, and distinct vocalizations are used to prevent hybridization with species that overlap its range. Gestation lasts approximately 60 days, and typically two young are born. The offspring are usually independent in two months, and can reproduce after one year. The Gray Mouse Lemur has a reproductive lifespan of five years, although captive individuals have been reported to live up to 15 years.

Although threatened by deforestation, habitat degradation, and live capture for the pet trade, it is considered one of Madagascar's most abundant small native mammals. However, climate change could have a negative effect on this species in the long term, despite its ability to survive temporary resource shortages.

Great Auk
The Great Auk, Pinguinus impennis, formerly of the genus Alca, was a large, flightless alcid that became extinct in the mid-19th century. It was the only modern species in the genus Pinguinus, a group of birds that formerly included one other species of flightless giant auk from the Atlantic Ocean region. It bred on rocky, isolated islands with easy access to both the ocean and a plentiful food supply, a rarity in nature that provided only a few breeding sites for the auks. When not breeding, the auks spent their time foraging in the waters of the North Atlantic, ranging as far south as New England and northern Spain through Canada, Greenland, Iceland, Norway, Ireland, and Great Britain.

The Great Auk was 75 to 85 cm tall and weighed around 5 kg, making it the largest member of the alcid family. It had a black back and a white belly. The black beak was heavy and hooked with grooves etched into its surface. During the breeding season, the Great Auk had a white patch over each eye. After the breeding season, the auk lost this patch, instead developing a white band stretching between the eyes. The wings were 15 cm long, rendering the bird flightless. Instead, the auk was a powerful swimmer, a trait that it used in hunting. Its favorite prey were fish, including Atlantic Menhaden and Capelin, and crustaceans. Although agile in the water, it was clumsy on land. Its main predators were Orcas, White-tailed Eagles, Polar Bears, and humans. Great Auk pairs mated for life. They nested in extremely dense and social colonies, laying one egg on bare rock. The egg was white with variable brown streaking. Both parents incubated for about six weeks before their young hatched. The young auks left the nest site after two or three weeks and the parents continued to care for them.

Humans had hunted the Great Auk for more than 100,000 years. It was an important part of many Native American cultures which coexisted with the bird, both as a food source and as a symbolic item. Many Maritime Archaic people were buried with Great Auk bones, and one was buried with a cloak made of over 200 auk skins. Early European explorers to the Americas used the auk as a convenient food source or as fishing bait, reducing its numbers. The bird's down was in high demand in Europe, a factor which largely eliminated the European populations by the mid-16th century. Scientists soon began to realize that the Great Auk was disappearing and it became the beneficiary of many early environmental laws, but this proved not to be enough. Its growing rarity increased interest from European museums and private collectors in obtaining skins and eggs of the bird. This trend eliminated the last of the Great Auks on 3 July 1844 on Eldey, Iceland. However, a record of a bird in 1852 is considered by some to be the last sighting of this species. The Great Auk is mentioned in a number of novels and the scientific journal of the American Ornithologists' Union is named The Auk in honor of this bird.

Greater Crested Tern
The Greater Crested Tern, Crested Tern or Swift Tern, (Thalasseus bergii), is a seabird in the tern family which nests in dense colonies on coastlines and islands in the tropical and subtropical Old World. Its five subspecies breed in the area from South Africa around the Indian Ocean to the central Pacific and Australia, all populations dispersing widely from the breeding range after nesting. This large tern is closely related to the Royal and Lesser Crested Terns, but can be distinguished by its size and bill colour.

The Greater Crested Tern has grey upperparts, white underparts, a yellow bill, and a shaggy black crest which recedes in winter. Its young have a distinctive appearance, with strongly patterned grey, brown and white plumage, and rely on their parents for food for several months after they have fledged. Like all members of the genus Thalasseus, the Greater Crested Tern feeds by plunge diving for fish, usually in marine environments; the male offers fish to the female as part of the courtship ritual.

This is an adaptable species which has learned to follow fishing boats for jettisoned bycatch, and to utilise unusual nest sites such as the roofs of buildings and artificial islands in salt pans and sewage works. Its eggs and young are taken by gulls and ibises, and human activities such as fishing, shooting and egg harvesting have caused local population declines. There are no global conservation concerns for this bird, which has a stable total population of more than 500,000 individuals.

Green and Golden Bell Frog
The Green and Golden Bell Frog (Litoria aurea), also named the Green Bell Frog, Green and Golden Swamp Frog and Green Frog, is a ground-dwelling tree frog native to eastern Australia. Despite its classification and climbing abilities, it does not live in trees and spends almost all of its time close to ground level. It can reach up to 11 centimetres (4.3 in) in length, making it one of Australia's largest frogs.

Coloured gold and green, the frogs are voracious eaters of insects but will also eat larger prey such as worms and mice. Unlike most frogs, they are active at day although this is mostly to tan in the sun. They tend to be less active in winter except in warmer or wetter periods, and breed in the warmer months. Males reach maturity after around nine months, while for the larger females, this does not occur until they are two years old. The frogs can engage in cannibalism, and males frequently attack and injure one another if they infringe on one another's space.

Many populations, particularly in the Sydney region, inhabit areas of frequent disturbance, such as golf courses, disused industrial land, brick pits and landfill areas. Though once one of the most common frogs in south-east Australia, the Green and Golden Bell Frog has endured major declines in population, particularly in highland areas,leading to its current classification as globally vulnerable. Its numbers have continued to fall and are threatened by habitat loss and degradation, pollution, introduced species, and parasites and pathogens, including the chytrid (Batrachochytrium dendrobatidis). As most of the remaining populations live on private land, the logistics of the conservation effort can be complicated. Despite the situation in Australia, the frog remains abundant in New Zealand and several other Pacific Islands, where it has been introduced.

Grey Currawong
The Grey Currawong (Strepera versicolor) is a large passerine bird native to southern Australia and Tasmania. One of three currawong species in the genus Strepera, it is closely related to the butcherbirds and Australian Magpie of the family Artamidae. It is a large crow-like bird, around 48 cm long on average, with yellow irises, and a heavy bill, and dark plumage with white undertail and wing patches. The male and female are similar in appearance. Six subspecies are recognised and are distinguished by overall plumage colour, which ranges from slate-grey for the nominate from New South Wales and eastern Victoria and subspecies plumbea from Western Australia, to sooty black for the Clinking Currawong of Tasmania and subspecies halmaturina from Kangaroo Island. All Grey Currawongs have a loud distinctive ringing or clinking call.

Within its range, the Grey Currawong is generally sedentary, although it is a winter visitor in the southeastern corner of Australia. Comparatively little studied, much of its behaviour and habits is poorly known. Omnivorous, it has a diet that includes a variety of berries, invertebrates, and small vertebrates. Less arboreal than the Pied Currawong, the Grey Currawong spends more time foraging on the ground. It builds nests high in trees, which has limited the study of its breeding habits. Unlike its more common relative, it has adapted poorly to human impact and has declined in much of its range. The habitat includes all kinds of forested areas as well as scrubland in dryer parts of the country.

Guinea Pig
The guinea pig (Cavia porcellus), also commonly called the cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not pigs, nor do they come from Guinea. They originated in the Andes, and studies based on biochemistry and hybridization suggest they are domesticated descendants of a closely related species of cavy such as Cavia aperea, C. fulgida, or C. tschudii, and therefore do not exist naturally in the wild. The guinea pig plays an important role in the folk culture of many Indigenous South American groups, especially as a food source, but also in folk medicine and in community religious ceremonies. Since the 1960s, efforts have been made to increase consumption of the animal outside South America.

In Western societies, the guinea pig has enjoyed widespread popularity as a household pet since its introduction by European traders in the 16th century. Their docile nature, their responsiveness to handling and feeding, and the relative ease of caring for them, continue to make the guinea pig a popular pet. Organizations devoted to competitive breeding of guinea pigs have been formed worldwide, and many specialized breeds of guinea pig, with varying coat colors and compositions, are cultivated by breeders.

Biological experimentation on guinea pigs has been carried out since the 17th century. The animals were frequently used as a model organism in the 19th and 20th centuries, resulting in the epithet "guinea pig" for a test subject, but have since been largely replaced by other rodents such as mice and rats. They are still used in research, primarily as models for human medical conditions such as juvenile diabetes, tuberculosis, scurvy, and pregnancy complications.

Gyromitra esculenta


Gyromitra esculenta, one of several species of fungi known as false morels, is an ascomycete fungus from the genus Gyromitra, widely distributed across Europe and North America. It normally sprouts in sandy soils under coniferous trees in spring and early summer. The fruiting body, or mushroom, is an irregular brain-shaped cap dark brown in colour which can reach 10 cm high and 15 cm wide, perched on a stout white stipe up to 6 cm high.

Although potentially fatal if eaten raw, Gyromitra esculenta is a popular delicacy in Scandinavia, Eastern Europe, and the upper Great Lakes region of North America. Although popular in some districts of the eastern Pyrenees, it is prohibited from sale to the public in Spain. It may be sold fresh in Finland, but it must be accompanied by warnings and instructions on correct preparation. It is eaten in omelettes, soups, or sautéed in Finnish cuisine.

Although it is still commonly parboiled before preparation, recent evidence suggests that even this procedure may not make the fungus entirely safe, thus raising concerns of risk even when prepared properly. When consumed, the false morel's principal active agent, gyromitrin, is hydrolyzed into the toxic compound monomethylhydrazine (MMH). The toxin affects the liver, central nervous system, and sometimes the kidneys. Symptoms of poisoning involve vomiting and diarrhea several hours after consumption, followed by dizziness, lethargy and headache. Severe cases may lead to delirium, coma and death after 5–7 days.

Hawksbill turtle
The hawksbill turtle (Eretmochelys imbricata) is a critically endangered sea turtle belonging to the family Cheloniidae. It is the only species in its genus. The species has a worldwide distribution, with Atlantic and Pacific subspecies. Eretmochelys imbricata imbricata is the Atlantic subspecies, while Eretmochelys imbricata bissa is found in the Indo-Pacific region.

The hawksbill's appearance is similar to that of other marine turtles. It has a generally flattened body shape, a protective carapace, and flipper-like arms, adapted for swimming in the open ocean. E. imbricata is easily distinguished from other sea turtles by its sharp, curving beak with prominent tomium, and the saw-like appearance of its shell margins. Hawksbill shells slightly change colors, depending on water temperature. While this turtle lives part of its life in the open ocean, it spends more time in shallow lagoons and coral reefs where it feeds on its primary prey, sea sponges. Some of the sponges eaten by E. imbricata are lethally toxic to other organisms. In addition, the sponges that hawksbills eat usually contain high concentrations of silica, making them one of few animals capable of eating siliceous organisms. They also feed on other invertebrates, such as comb jellies and jellyfish.

Because of human fishing practices, E. imbricata populations are threatened with extinction. The World Conservation Union. classifies the Hawksbill as critically endangered. Hawksbill shells are the primary source of tortoise shell material, used for decorative purposes. The Convention on International Trade in Endangered Species outlaws the capture and trade of hawksbill turtles and products derived from them.

Herrerasaurus
Herrerasaurus (meaning "Herrera's lizard", after the name of the rancher who discovered the first fossil of the animal) was one of the earliest dinosaurs. All known specimens of this carnivore have been discovered in rocks of early Carnian age (late Triassic, around 228 million years ago) in northwestern Argentina. The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 and is the only species assigned to the genus. The names Ischisaurus and Frenguellisaurus are synonymous with Herrerasaurus.

For many years, the classification of Herrerasaurus was unclear, as the animal was initially known from very fragmentary remains; it has been hypothesized to be a basal theropod, a basal sauropodomorph, a basal saurischian, or not a dinosaur at all. However, with the discovery of a mostly complete skeleton and skull in 1988, Herrerasaurus has been classified as either an early theropod or an early saurischian in at least five recent reviews of theropod evolution. It was a member of the Herrerasauridae, a group of similar animals which were among the earliest of the dinosaurian evolutionary radiation.

Hippopotamus
The hippopotamus (Hippopotamus amphibius), or hippo, from the ancient Greek for "river horse" (Ιπποπόταμος), is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae (the other is the Pygmy Hippopotamus.) The hippopotamus is the third largest land animal (after the elephant and the white rhinoceros) and the heaviest extant artiodactyl, despite being considerably shorter than the giraffe.

The hippopotamus is semi-aquatic, inhabiting rivers and lakes where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water. They emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land.

Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about. The common ancestor of whales and hippos split from other even-toed ungulates around. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around.

The hippopotamus is recognizable by its barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs and tremendous size. It is the third-largest land mammal by weight (between 1½ and 3 tonnes), behind the white rhinoceros (1½ to 3½ tonnes) and the three species of elephant (3 to 9 tonnes). Despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h over short distances. The hippopotamus is one of the most aggressive creatures in the world and is often regarded as one of the most dangerous animals in Africa. There are an estimated 125,000 to 150,000 hippos throughout Sub-Saharan Africa; Zambia (40,000) and Tanzania (20,000–30,000) possess the largest populations. They are still threatened by habitat loss and poaching for their meat and ivory canine teeth.

Homo floresiensis
Homo floresiensis ("Flores Man", nicknamed "hobbit") is a possible species, now believed to be extinct, in the genus Homo. The remains were discovered in 2003 on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete cranium (skull). These remains have been the subject of intense research to determine whether they represent a species distinct from modern humans, and the progress of this scientific controversy has been closely followed by the news media at large. This hominin is remarkable for its small body and brain and for its survival until relatively recent times (possibly as recently as 12,000 years ago). Recovered alongside the skeletal remains were stone tools from archaeological horizons ranging from 94,000 to 13,000 years ago.

The discoverers (archaeologist Mike Morwood and colleagues) proposed that a variety of features, both primitive and derived, identify these individuals as belonging to a new species, H. floresiensis, within the taxonomic tribe of Hominini. Hominini currently comprises the extant species human (the only living member of the genus Homo), bonobo (genus Pan), and chimpanzee (genus Pan); their ancestors; and the extinct lineages of their common ancestor. The discoverers also proposed that H. floresiensis lived contemporaneously with modern humans (Homo sapiens) on Flores.

Doubts that the remains constitute a new species were soon voiced by the Indonesian anthropologist Teuku Jacob, who suggested that the skull of LB1 was a microcephalic modern human. Two studies by paleoneurologist Dean Falk and her colleagues (2005, 2007) refuted this possibility. Falk et al. (2005) has been refuted by Martin et al. (2006) and Jacob et al. (2006) and defended by Morwood (2005) and Argue, Donlon et al. (2006).

Two orthopedic researches published in 2007 both reported evidence to support species status for H. floresiensis. A study of three tokens of carpal (wrist) bones concluded there were similarities to the carpal bones of a chimpanzee or an early hominin such as Australopithecus and also differences from the bones of modern humans. A study of the bones and joints of the arm, shoulder, and lower limbs also concluded that H. floresiensis was more similar to early humans and apes than modern humans. In 2009, the publication of a cladistic analysis and a study of comparative body measurements provided further support for the hypothesis that H. floresiensis and Homo sapiens are separate species.

Critics of the claim for species status continue to believe that these individuals are Homo sapiens possessing pathologies of anatomy and physiology. A second hypothesis in this category is that the individuals were born without a functioning thyroid, resulting in a type of endemic cretinism (myxoedematous, ME).

Common House Martin
The Common House Martin (Delichon urbicum), sometimes called the Northern House Martin or, particularly in Europe, just House Martin, is a migratory passerine bird of the swallow family which breeds in Europe, north Africa and temperate Asia; and winters in sub-Saharan Africa and tropical Asia. It feeds on insects which are caught in flight, and it migrates to climates where flying insects are plentiful. It has a blue head and upperparts, white rump and pure white underparts, and is found in both open country and near human habitation. It is similar in appearance to the two other martin species of the Delichon genus, which are both endemic to eastern and southern Asia. It has two accepted subspecies.

Both the scientific and colloquial name of the bird are related to its use of man-made structures. It builds a closed cup nest from mud pellets under eaves or similar locations on buildings usually in colonies, but sometimes fouling below nests can be a problem.

It is hunted by the Eurasian Hobby (Falco subbuteo), and like other birds is affected by internal parasites and external fleas and mites, but its large range and population mean that it is not threatened globally. Its proximity to man is generally accepted leading to some cultural and literary references.

Humpback whale
The humpback whale (Megaptera novaeangliae) is a species of baleen whale. One of the larger rorqual species, adults range in length from 12 - 16 m and weigh approximately 36000 kg. The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head. It is an acrobatic animal, often breaching and slapping the water. Males produce a complex whale song, which lasts for 10 to 20 minutes and is repeated for hours at a time. The purpose of the song is not yet clear, although it appears to have a role in mating.

Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 kilometres each year. Humpbacks feed only in summer, in polar waters, and migrate to tropical or sub-tropical waters to breed and give birth in the winter. During the winter, humpbacks fast and live off their fat reserves. The species' diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net feeding technique.

Like other large whales, the humpback was and is a target for the whaling industry. Due to over-hunting, its population fell by an estimated 90% before a whaling moratorium was introduced in 1966. Stocks have since partially recovered; however, entanglement in fishing gear, collisions with ships, and noise pollution also remain concerns. There are at least 80,000 humpback whales worldwide. Once hunted to the brink of extinction, humpbacks are now sought by whale-watchers, particularly off parts of Australia, Canada, and the United States.

Icelandic horse
The Icelandic horse is a breed of horse developed in Iceland. Although the horses are small, at times pony-sized, most registries for the Icelandic refer to it as a horse. Icelandic horses are late-developers, but are also long-lived and hardy. In their native country they have few diseases; Icelandic law prevents horses from being imported into the country and exported animals are not allowed to return. The Icelandic displays two gaits in addition to the typical walk, trot, and canter/gallop commonly displayed by other breeds. The only breed of horse in Iceland, they are also popular internationally, and sizable populations exist in Europe and North America. The breed is still used for traditional farm work in its native country, as well as for leisure, showing, and racing.

Developed from ponies taken to Iceland by Scandinavian settlers in the 9th and 10th centuries, the breed is mentioned in literature and historical records throughout Icelandic history; the first reference to a named horse appears in the 12th century. Horses were venerated in Norse mythology, a custom brought to Iceland by the country's earliest settlers. Selective breeding over the centuries has developed the breed into its current form. Natural selection has also played a role, as the harsh Icelandic climate eliminated many horses through cold and starvation. In the 1780s, much of the breed was wiped out in the aftermath of a volcanic eruption. The first breed society for the Icelandic horse was created in Iceland in 1904, and today the breed is represented by organizations in 19 different nations, organized under a parent association, the International Federation of Icelandic Horse Associations.

Iguanodon
Iguanodon (, meaning "Iguana tooth") is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs. Many species of Iguanodon have been named, dating from the Kimmeridgian age of the Late Jurassic Period to the Cenomanian age of the Late Cretaceous Period from Asia, Europe, and North America. However, research in the first decade of the 2000s suggests that there is only one well-substantiated species: I. bernissartensis, that lived from the Barremian to the early Aptian (Early Cretaceous) in Europe, between about 130 and 120 million years ago. Iguanodon's most distinctive features were its large thumb spikes, which were possibly used for defence against predators and foraging for food.

Discovered in 1822 and described three years later by English geologist Gideon Mantell, Iguanodon was the second dinosaur formally named, after Megalosaurus. Together with Megalosaurus and Hylaeosaurus, it was one of the three genera originally used to define Dinosauria. A large, bulky herbivore, Iguanodon is a member of Iguanodontia, along with the duck-billed hadrosaurs. The taxonomy of this genus continues to be a topic of study as new species are named or long-standing ones reassigned to other genera.

Scientific understanding of Iguanodon has evolved over time as new information has been obtained from the fossils. The numerous specimens of this genus, including nearly complete skeletons from two well-known bonebeds, have allowed researchers to make informed hypotheses regarding many aspects of the living animal, including feeding, movement, and social behaviour. As one of the first scientifically well-known dinosaurs, Iguanodon has occupied a small but notable place in the public's perception of dinosaurs, its artistic representation changing significantly in response to new interpretations of its remains.

Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly. Detection is complicated as pathogens can evolve rapidly, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts.

To survive this challenge, multiple mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. Jawed vertebrates, including humans, have even more sophisticated defense mechanisms. The typical vertebrate immune system consists of many types of proteins, cells, organs, and tissues that interact in an elaborate and dynamic network. As part of this more complex immune response, the human immune system adapts over time to recognize specific pathogens more efficiently. This adaptation process is referred to as "adaptive immunity" or "acquired immunity" and creates immunological memory. Immunological memory created from a primary response to a specific pathogen, provides an enhanced response to secondary encounters with that same, specific pathogen. This process of acquired immunity is the basis of vaccination. Primary response can take 2 days to even 2 weeks to develop. After the body gains immunity towards a certain pathogen, when infection by that pathogen occurs again, the immune response is called the secondary response.

Disorders in the immune system can result in disease, including autoimmune diseases, inflammatory diseases and cancer. Immunodeficiency diseases occur when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, and lupus erythematosus. Immunology covers the study of all aspects of the immune system, having significant relevance to health and diseases. Further investigation in this field is expected to play a serious role in promotion of health and treatment of diseases.

Introduction to viruses
A virus is a biological agent that reproduces inside the cells of living hosts. When infected by a virus, a host cell is forced to produce many thousands of identical copies of the original virus, at an extraordinary rate. Unlike most living things, viruses do not have cells that divide; new viruses are assembled in the infected host cell. Over 2,000 species of viruses have been discovered.

A virus consists of two or three parts: Genes, made from either DNA or RNA, long molecules that carry the genetic information; a protein coat that protects the genes; and some viruses have an envelope of fat that surrounds and protects them when they are not contained within a host cell. Viruses vary in shape from the simple helical and icosahedral to more complex structures. Viruses are about 100 times smaller than bacteria, it would take 30,000 to 750,000 of them, side by side, to stretch to 1 cm.

Viruses spread in many different ways. Plant viruses are often spread from plant to plant by insects and other organisms, known as vectors. Some viruses of animals are spread by blood-sucking insects. Each species of virus relies on a particular method. Whereas viruses such as influenza are spread through the air by people when they cough or sneeze, others such as norovirus, which are transmitted by the faecal-oral route, contaminate hands, food and water. Rotavirus is often spread by direct contact with infected children. Human Immuno-deficiency Virus HIV, is one of several major viruses that are transmitted during sex. The origins of viruses is unclear: some may have evolved from plasmids—pieces of DNA that can move between cells—while others may have evolved from bacteria.

Viral infections often cause disease in humans and animals, however they are usually eliminated by the immune system, conferring lifetime immunity to the host for that virus. Antibiotics have no effect on viruses, but antiviral drugs have been developed to treat life-threatening infections. Vaccines that produce lifelong immunity can prevent some viral infections.

Island Fox
The Island Fox (Urocyon littoralis) is a small fox that is native to six of the eight Channel Islands of California. There are six subspecies of the fox, each unique to the island it lives on, reflecting its evolutionary history. Other names for the Island Fox include Coast Fox, Short-Tailed Fox, Island Gray Fox, Channel Islands Fox, Channel Islands Gray Fox, California Channel Island Fox and Insular Gray Fox.

Jaguar
The jaguar (Panthera onca) is a big cat, a feline in the Panthera genus, and is the only Panthera species found in the Americas. The jaguar is the third-largest feline after the tiger and the lion, and the largest and most powerful feline in the Western Hemisphere. The jaguar's present range extends from Mexico across much of Central America and south to Paraguay and northern Argentina. Apart from a known and possibly breeding population in Arizona (southeast of Tucson), the cat has largely been extirpated from the United States since the early 1900s.

This spotted cat most closely resembles the leopard physically, although it is usually larger and of sturdier build and its behavioral and habitat characteristics are closer to those of the tiger. While dense rainforest is its preferred habitat, the jaguar will range across a variety of forested and open terrain. It is strongly associated with the presence of water and is notable, along with the tiger, as a feline that enjoys swimming. The jaguar is a largely solitary, stalk-and-ambush predator, and is opportunistic in prey selection. It is also an apex and keystone predator, playing an important role in stabilizing ecosystems and regulating the populations of prey species. The jaguar has an exceptionally powerful bite, even relative to the other big cats. This allows it to pierce the shells of armoured reptiles and to employ an unusual killing method: it bites directly through the skull of prey between the ears to deliver a fatal bite to the brain.

The jaguar is a near threatened species and its numbers are declining. Threats include habitat loss and fragmentation. While international trade in jaguars or their parts is prohibited, the cat is still regularly killed by humans, particularly in conflicts with ranchers and farmers in South America. Although reduced, its range remains large; given its historical distribution, the jaguar has featured prominently in the mythology of numerous indigenous American cultures, including that of the Maya and Aztec.

Javan Rhinoceros
The Javan Rhinoceros (Sunda Rhinoceros to be more precise) or Lesser One-horned Rhinoceros (Rhinoceros sondaicus) is a member of the family Rhinocerotidae and one of five extant rhinoceroses. It belongs to the same genus as the Indian Rhinoceros, and has similar mosaicked skin which resembles armor, but at 3.1–3.2 m (10–10.5 feet) in length and 1.4–1.7 m (4.6–5.8 ft) in height, it is smaller than the Indian Rhinoceros, and is closer in size to the Black Rhinoceros. Its horn is usually less than 25 cm (10 inches), smaller than those of the other rhino species.

Once the most widespread of Asian rhinoceroses, the Javan Rhinoceros ranged from the islands of Indonesia, throughout Southeast Asia, and into India and China. The species is now critically endangered, with only two known populations in the wild, and none in zoos. It is possibly the rarest large mammal on earth. A population of at least 40–50 live in Ujung Kulon National Park on the island of Java in Indonesia and a small population, estimated in 2007 to be no more than eight, survives in Cat Tien National Park in Vietnam. The decline of the Javan Rhinoceros is attributed to poaching, primarily for their horns, which are highly valued in traditional Chinese medicine, fetching as much as $30,000 per kilogram on the black market. Loss of habitat, especially as the result of wars, such as the Vietnam War, in Southeast Asia, has also contributed to the species's decline and hindered recovery. The remaining range is only within two nationally protected areas, but the rhinos are still at risk from poachers, disease and loss of genetic diversity leading to inbreeding depression.

The Javan Rhino can live approximately 30–45 years in the wild. It historically inhabited lowland rain forest, wet grasslands and large floodplains. The Javan Rhino is mostly solitary, except for courtship and child-rearing, though groups may occasionally congregate near wallows and salt licks. Aside from humans, adults have no predators in their range. The Javan Rhino usually avoids humans, but will attack when it feels threatened. Scientists and conservationists rarely study the animals directly due to their extreme rarity and the danger of interfering with such an endangered species. Researchers rely on camera traps and fecal samples to gauge health and behavior. Consequently, the Javan Rhino is the least studied of all rhino species.

Kakapo
The Kakapo (Māori: kākāpō, meaning night parrot), Strigops habroptila (Gray, 1845), also called owl parrot, is a species of large, flightless nocturnal parrot endemic to New Zealand. It has finely blotched yellow-green plumage, a distinct facial disc of sensory, vibrissa-like feathers, a large grey beak, short legs, large feet, and wings and a tail of relatively short length. A certain combination of traits makes it unique among its kind—it is the world's only flightless parrot, the heaviest parrot, nocturnal, herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate, no male parental care, and is the only parrot to have a polygynous lek breeding system. It is also possibly one of the world's longest-living birds. Its anatomy typifies the tendency of bird evolution on oceanic islands with few predators and abundant food: a generally robust physique, with accretion of thermodynamic efficiency at the expense of flight abilities, reduced wing muscles, a diminished keel on the sternum.

The Kakapo is critically endangered; as of February 2010, only living individuals are known, most of which have been given names. The common ancestor of the Kakapo and the genus Nestor became isolated from the remaining parrot species when New Zealand broke off from Gondwana, around 82 million years ago. Around 70 million years ago, the kakapo diverged from the genus Nestor. In the absence of mammalian predators, it lost the ability to fly. Because of Polynesian and European colonisation and the introduction of predators such as cats, rats, and stoats,the Kakapo was almost wiped out. Conservation efforts began in the 1890s, but they were not very successful until the implementation of the Kakapo Recovery Plan in the 1980s. As of January 2009, surviving Kakapo are kept on two predator-free islands, Codfish (Whenua Hou) and Anchor islands, where they are closely monitored. Two large Fiordland islands, Resolution and Secretary, have been the subject of large-scale ecological restoration activities to prepare self-sustaining ecosystems with suitable habitat for the Kakapo.

The conservation of the Kakapo has made the species well known. Many books and documentaries detailing the plight of the Kakapo have been produced in recent years, one of the earliest being Two in the Bush, made by Gerald Durrell for the BBC in 1962. A feature length documentary, The Unnatural History of the Kakapo, won two major awards at the Reel Earth Environmental Film Festival. Two of the most significant documentaries, both made by NHNZ, are Kakapo - Night Parrot (1982) and To Save the Kakapo (1997). The BBC's Natural History Unit also featured the Kakapo, including a sequence with Sir David Attenborough in The Life of Birds. It was also one of the endangered animals that Douglas Adams and Mark Carwardine set out to find for the radio series and book Last Chance to See. An updated version of the series has been produced for BBC TV, in which Stephen Fry and Carwardine revisit the animals to see how they are getting on almost 20 years later, and in January 2009, they spent time filming the Kakapo on Codfish Island.

The Kakapo, like many other New Zealand bird species, was historically important to Māori, the indigenous people of New Zealand, appearing in many of their traditional legends and folklore. It was also hunted and used as a resource by Māori, both for its meat as a food source and for its feathers, which were used to make highly valued pieces of clothing.

Killer whale
The killer whale (Orcinus orca), commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas. Killer whales as a species have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals such as sea lions, seals, walruses and even large whales. Killer whales are regarded as apex predators, lacking natural predators.

Killer whales are highly social; some populations are composed of matrilineal family groups which are the most stable of any animal species. Their sophisticated hunting techniques and vocal behaviors, which are often specific to a particular group and passed across generations, have been described as manifestations of culture.

The IUCN currently assesses the orca's conservation status as data deficient because of the likelihood that one or more killer whale types are separate species. Some local populations are considered threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), capture for marine mammal parks, and conflicts with fisheries. In late 2005, the killer whales known as the "southern resident killer whales" were placed on the U.S. Endangered Species list.

Wild killer whales are not considered a threat to humans, although there have been cases of captives killing or injuring their handlers at marine theme parks. Killer whales feature strongly in the mythologies of indigenous cultures. In Western cultures, it has had a reputation for being a fearsome predator.

King Vulture
The King Vulture, Sarcoramphus papa, is a large bird found in Central and South America. It is a member of the New World vulture family Cathartidae. This vulture lives predominantly in tropical lowland forests stretching from southern Mexico to northern Argentina, though some believe that William Bartram's Painted Vulture of Florida may be of this species. It is the only surviving member of the genus Sarcoramphus, though fossil members are known.

It is large and predominantly white, with gray to black ruff, flight, and tail feathers. Its head and neck are bald, with the skin color varying, including yellow, orange, blue, purple, and red. The King Vulture has a very noticeable yellow fleshy caruncle on its beak. This vulture is a scavenger and it often makes the initial cut into a fresh carcass. It also displaces smaller New World vulture species from a carcass. King Vultures have been known to live for up to 30 years in captivity.

King Vultures were popular figures in the Mayan codices as well as in local folklore and medicine. Though currently listed as Least Concern by the IUCN, they are decreasing in number, due primarily to habitat loss.

Komodo dragon
The Komodo dragon (Varanus komodoensis) is a large species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. A member of the monitor lizard family (Varanidae), it is the largest living species of lizard, growing to an average length of 2 to 3 m and weighing around 70 kg. Their unusual size has been attributed to island gigantism, since there are no other carnivorous animals to fill the niche on the islands where they live. However, recent research suggests that the large size of komodo dragons may be better understood as representative of a relic population of very large varanid lizards that once lived across Indonesia and Australia, most of which, along with other megafauna, died out after contact with modern humans. Fossils very similar to V. komodoensis have been found in Australia dating to greater than 3.8 million years ago, and its body size remained stable on Flores, one of the handful of Indonesian islands where it is currently found, ever since Flores (along with neighboring islands) were isolated by rising sea levels approximately 900,000 years ago. As a result of their size, these lizards dominate the ecosystems in which they live. Although Komodo dragons eat mostly carrion, they will also hunt and ambush prey including invertebrates, birds, and mammals.

Mating begins between May and August, and the eggs are laid in September. About twenty eggs are deposited in abandoned megapode nests and incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and therefore dwell in trees, safe from predators and cannibalistic adults. They take around three to five years to mature, and may live as long as fifty years. They are among the rare vertebrates capable of parthenogenesis, in which females may lay viable eggs if males are absent.

Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation make them popular zoo exhibits. In the wild their range has contracted due to human activities and they are listed as vulnerable by the IUCN. They are protected under Indonesian law, and a national park, Komodo National Park, was founded to aid protection efforts.

Lactarius indigo
Lactarius indigo, commonly known as the indigo milk cap, the indigo Lactarius or the blue Lactarius, is a species of fungus in the Russulaceae family of mushrooms. A widely distributed species, it grows naturally in eastern North America, East Asia, and Central America. In Europe, it has so far only been found in southern France. L. indigo grows on the ground in both deciduous and coniferous forests, where it forms mycorrhizal associations with a broad range of trees. The fruiting body color ranges from dark blue in fresh specimens to pale blue-gray in older ones. The milk, or latex, that oozes when the mushroom tissue is cut or broken—a feature common to all members of the Lactarius genus—is also indigo blue, but slowly turns green upon exposure to air. The cap is typically between 5 to 15 cm broad, and the stem 2 to 8 cm tall by 1 to 2.5 cm thick. It is an edible mushroom, and is sold in rural markets in Mexico, Guatemala, and China.

Lambeosaurus
Lambeosaurus (, meaning "Lambe's lizard") is a genus of hadrosaurid dinosaur that lived about 76 to 75 million years ago, in the Late Cretaceous Period (Campanian) of North America. This bipedal/quadrupedal, herbivorous dinosaur is known for its distinctive hollow cranial crest, which in the best-known species resembled a hatchet. Several possible species have been named, from Alberta (Canada), Montana (USA), and Baja California (Mexico), but only the two Canadian species are currently well known. At about 15 meters (50 ft) long, the Mexican species L. laticaudus was one of the longest ornithischians. The other species were more modestly sized.

Lambeosaurus was belatedly described in 1923 by William Parks, over twenty years after the first material was studied by Lawrence Lambe. The genus has had a complicated taxonomic history, in part because small-bodied crested hadrosaurids now recognized as juveniles were once thought to belong to their own genera and species. Currently, the various skulls assigned to the type species L. lambei are interpreted as showing age differences and sexual dimorphism. Lambeosaurus was closely related to the better known Corythosaurus, which is found in slightly older rocks, as well as the less well-known genera Hypacrosaurus and Olorotitan. All had unusual crests, which are now generally assumed to have served social functions like noisemaking and recognition.

Lemurs
Lemurs (, US dict: lē′·mər) are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures (ghosts or spirits) of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species. Although lemurs often are confused with ancestral primates, the anthropoid primates (monkeys, apes, and humans) did not evolve from them; instead, lemurs merely share morphological and behavioral traits with basal primates. Lemurs arrived in Madagascar around 62 to 65 mya by rafting on mats of vegetation at a time when ocean currents favored oceanic dispersal to the island. Since that time, lemurs have evolved to cope with an extremely seasonal environment and their adaptations give them a level of diversity that rivals that of all other primate groups. Until shortly after humans arrived on the island around 2,000 years ago, there were lemurs as large as a male gorilla. Today, there are nearly 100 species of lemurs, and most of those species were discovered or promoted to full species status since the 1990s; however, lemur taxonomic classification is controversial and depends on which species concept is used. Even the higher-level taxonomy is disputed, with some experts preferring to place most lemurs within the infraorder Lemuriformes, while others prefer Lemuriformes to contain all living strepsirrhines, placing all lemurs in superfamily Lemuroidea and all lorises and galagos in superfamily Lorisoidea.

Ranging in size from 30 g (1.1 oz) to 9 kg (20 lb), lemurs share many common, basal primate traits, such as divergent digits on their hands and feet and nails instead of claws (in most species). However, their brain-to-body size ratio is smaller than that of anthropoid primates, and among many other traits they share with other strepsirrhine primates, they have a "wet nose" (rhinarium). Lemurs are generally the most social of the strepsirrhine primates and communicate more with scents and vocalizations than with visual signals. Many lemur adaptations are in response to Madagascar's highly seasonal environment. Lemurs have relatively low basal metabolic rates and may exhibit seasonal breeding, dormancy (such as hibernation or torpor), or female social dominance. Most eat a wide variety of fruits and leaves, while some are specialists. Although many share similar diets, different species of lemur share the same forests by differentiating niches.

Lemur research focused on taxonomy and specimen collection during the 18th and 19th centuries. Although field observations trickled in from early explorers, modern studies of lemur ecology and behavior did not begin in earnest until the 1950s and 1960s. Initially hindered by political instability and turmoil on Madagascar during the mid-1970s, field studies resumed in the 1980s and have greatly increased our understanding of these primates. Research facilities like the Duke Lemur Center have provided research opportunities under more controlled settings. Lemurs are important for research because their mix of primitive characteristics and traits shared with anthropoid primates can yield insights on primate and human evolution. However, many lemur species are threatened with extinction due to habitat loss and hunting. Although local traditions generally help protect lemurs and their forests, illegal logging, widespread poverty, and political instability hinder and undermine conservation efforts.

Evolutionary history of lemurs
The evolutionary history of lemurs occurred in isolation from other primates on the island of Madagascar for at least 40 million years. Lemurs are prosimian primates belonging to the suborder Strepsirrhini, which branched off from other primates less than 63 mya (million years ago). They share some traits with the most basal primates, and thus are often confused as being ancestral to modern monkeys, apes, and humans. Instead, they merely resemble ancestral primates.

Lemurs are thought to have evolved during the Eocene or earlier, sharing a closest common ancestor with lorisiforms. Fossils from Africa and tests of nuclear DNA suggest that lemurs made their way to Madagascar between 40 and 52 mya. Molecular tests offer an alternative date range of 62 to 65 mya. An ancestral lemur population is thought to have inadvertently rafted to the island on a floating mat of vegetation, although hypotheses for land bridges and island hopping have also been proposed. The timing and number of hypothesized colonizations has traditionally hinged on the phylogenetic affinities of the Aye-aye, the most basal member of the lemur clade.

Having undergone their own independent evolution on Madagascar, lemurs have diversified to fill many niches normally filled by other types of mammals. They include the smallest primates in the world, and once included some of the largest. Since the arrival of humans approximately 2,000 years ago, they are now restricted to 10% of the island, or approximately 60000 km2, and many are facing extinction. For this reason, researchers have been trying to identify and assess every species. Over the last 10 to 20 years, there has been a steep increase in the number of recognized lemur species and subspecies, both through the discovery of new species and the elevation of existing subspecies to full species status. Currently there are approximately 100 or more recognized species or subspecies of living lemur, which are divided into five families and 15 genera. If the extinct subfossil lemurs are included, an additional three families, eight genera, and 17 species would be included. The recent rise in species numbers is due to both improved genetic analysis and a push in conservation to encourage the protection of isolated and distinct lemur populations. Not everyone in the scientific community supports these taxonomic changes, with some preferring instead an estimate of 50 living species.

Lion
The lion (Panthera leo) is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg (550 lb) in weight, it is the second-largest living cat after the tiger. Wild lions currently exist in Sub-Saharan Africa and in Asia with a critically endangered remnant population in Gir Forest National Park in India, having disappeared from North Africa and Southwest Asia in historic times. Until the late Pleistocene, about 10,000 years ago, the lion was the most widespread large land mammal after humans. They were found in most of Africa, across Eurasia from western Europe to India, and in the Americas from the Yukon to Peru.

Lions live for ten to fourteen years in the wild, while in captivity they can live longer than twenty years. In the wild, males seldom live longer than ten years, as injuries sustained from continual fighting with rival males greatly reduce their longevity. They typically inhabit savanna and grassland, although they may take to bush and forest. Lions are unusually social compared to other cats. A pride of lions consists of related females and offspring and a small number of adult males. Groups of female lions typically hunt together, preying mostly on large ungulates. Lions are apex and keystone predators, although they scavenge as opportunity allows. While lions do not typically hunt humans, some have been known to do so.

The lion is a vulnerable species, having seen a possibly irreversible population decline of thirty to fifty percent over the past two decades in its African range. Lion populations are untenable outside designated reserves and national parks. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are currently the greatest causes of concern. Lions have been kept in menageries since Roman times and have been a key species sought for exhibition in zoos the world over since the late eighteenth century. Zoos are cooperating worldwide in breeding programs for the endangered Asiatic subspecies.

Visually, the male lion is highly distinctive and is easily recognized by its mane. The lion, particularly the face of the male, is one of the most widely recognized animal symbols in human culture. Depictions have existed from the Upper Paleolithic period, with carvings and paintings from the Lascaux and Chauvet Caves, through virtually all ancient and medieval cultures where they once occurred. It has been extensively depicted in literature, in sculptures, in paintings, on national flags, and in contemporary films and literature.

Loggerhead sea turtle
The loggerhead sea turtle (Caretta caretta), or loggerhead, is an oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The loggerhead is the world's largest hard-shelled turtle, measuring up to 213 cm long when fully grown. The adult loggerhead sea turtle weighs approximately 135 kg. The skin ranges from yellow to brown in color, and the shell is typically reddish-brown. There are no external differences in gender until the turtle becomes an adult. The most obvious difference being, adult males have thicker tails and shorter plastrons than the females.

The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian oceans as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years.

The loggerhead sea turtle is omnivorous, feeding mainly on bottom dwelling invertebrates. Its large and powerful jaws serve as an effective tool in dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine organisms such as sharks.

Loggerheads are considered an endangered species and are protected by the International Union for the Conservation of Nature. Untended fishing gear is responsible for many loggerhead deaths. Turtles also suffocate when they are accidentally trapped in fishing trawls. Turtle excluder devices (TEDs) have been implemented in efforts to reduce mortality by providing the turtle an escape route. Loss of suitable nesting beaches and the introduction of exotic predators has also taken a toll on loggerhead populations. Efforts to restore their numbers will require international cooperation since the turtles roam vast areas of ocean and critical nesting beaches are scattered among several countries.

Lundomys molitor
Lundomys molitor, also known as Lund's Amphibious Rat or the Greater Marsh Rat, is a semiaquatic rat species from southeastern South America. Its distribution is now restricted to Uruguay and nearby Rio Grande do Sul, Brazil, but it previously ranged east into Minas Gerais, Brazil, and west into eastern Argentina. The Argentinean form may have been distinct from the living form from Brazil and Uruguay. L. molitor is a large rodent, with the head and body length averaging 193 mm (7.60 in), characterized by a long tail, large hindfeet, and long and dense fur. It builds nests above the water, supported by reeds, and it is not currently threatened.

Its external morphology is similar to that of Holochilus brasiliensis and over the course of its complex taxonomic history, it has been confused with that species, but other features support its placement in a distinct genus, Lundomys. Within the family Cricetidae and subfamily Sigmodontinae, it is a member of a group of specialized oryzomyine rodents that also includes Holochilus, Noronhomys, Carletonomys, and Pseudoryzomys.

Lycoperdon echinatum
Lycoperdon echinatum, commonly known as the spiny puffball or the spring puffball, is a type of puffball mushroom in the genus Lycoperdon. The saprobic species has been found in Africa, Europe, Central America and North America, where it grows on soil in deciduous woods, glades, and pastures. It has been proposed that North American specimens be considered a separate species, Lycoperdon americanum, but this suggestion has not been followed by most authors. Molecular analysis indicates that Lycoperdon echinatum is closely related to the puffball genus Handkea.

The fruit bodies of L. echinatum are 2 – wide by 2 – tall, supported by a small base, and densely covered with spines that are up to 0.6 cm long. The spines can fall off in maturity, leaving a net-like pattern of scars on the underlying surface. Initially white in color, the puffballs turn a dark brown as they mature, at the same time changing from nearly round to somewhat flattened. Young specimens of L. echinatum resemble another edible spiny puffball, Lycoperdon pulcherrimum, but this latter species does not turn brown as it ages. The fruit bodies are edible when young, when the interior is white and firm and before it has turned into a powdery brown mass of spores. Laboratory tests have shown that extracts of the fruit bodies can inhibit the growth of several bacteria that are pathogenic to humans.

Macaroni Penguin
The Macaroni Penguin (Eudyptes chrysolophus) is a species of penguin found from the Subantarctic to the Antarctic Peninsula. One of six species of crested penguin, it is very closely related to the Royal Penguin, and some authorities consider the two to be a single species. It bears a distinctive yellow crest, and the face and upperparts are black and sharply delineated from the white underparts. Adults weigh on average 5.5 kg (12 lb) and are 70 cm (28 in) in length. The male and female are similar in appearance although the male is slightly larger with a relatively larger bill. Like all penguins, it is flightless, with a streamlined body and wings stiffened and flattened into flippers for a marine lifestyle.

The diet consists of a variety of crustaceans, mainly krill, as well as small fish and cephalopods; the species consumes more marine life annually than any other species of seabird. These birds moult once a year, spending about three to four weeks ashore, before returning to the sea. Numbering up to 100,000 individuals, the breeding colonies of the Macaroni Penguin are among the largest and densest of all penguin species. After spending the summer months breeding, penguins disperse into the oceans for six months; a 2009 study found that Macaroni Penguins from Kerguelen travelled over 10000 km in the central Indian Ocean. With about 18 million individuals, the Macaroni Penguin is the most numerous penguin species. However, widespread decline in populations have been recorded since the mid 1970s. These factors result in their conservation status being reclassified as vulnerable.

Major urinary proteins
Major urinary proteins (Mups), also known as α2u-globulins, are a subfamily of proteins found in abundance in the urine and other secretions of many animals. Mups provide a small range of identifying information about the donor animal, when detected by the vomeronasal organ of the receiving animal. They belong to a larger family of proteins known as lipocalins. Mups are encoded by a cluster of genes, located adjacent to each other on a single stretch of DNA, that varies greatly in number between species: from at least 21 functional genes in mice to none in humans. Mup proteins form a characteristic glove shape, encompassing a ligand-binding pocket that accommodates specific small, organic chemicals.

Urinary proteins were first reported in rodents in 1932, during studies by Thomas Addis into the cause of proteinuria. They are potent human allergens, and are largely responsible for a number of animal allergies, including to cats, horses and rodents. Their endogenous function within an animal is unknown, but may involve regulating energy expenditure. However, as secreted proteins they play multiple roles in chemical communication between animals, functioning as pheromone transporters and stabilizers in rodents and pigs. Mups can also act as protein pheromones themselves. They have been demonstrated to promote aggression in male mice, and one specific Mup protein found in male mouse urine is sexually attractive to female mice. Mups can also function as signals between different species: mice display an instinctive fear response on the detection of Mups derived from predators such as cats and rats.

Majungasaurus
Majungasaurus ( "Mahajanga lizard") is a genus of abelisaurid theropod dinosaur that lived in Madagascar from 70 to 65 million years ago, at the end of the Cretaceous Period. Only one species (M. crenatissimus) has been identified. This dinosaur was briefly called Majungatholus, a name which is now considered a junior synonym of Majungasaurus.

Like other abelisaurids, Majungasaurus was a bipedal predator with a short snout. Although the forelimbs are not completely known, they were very short, while the hindlimbs were longer and very stocky. It can be distinguished from other abelisaurids by its wider skull, the very rough texture and thickened bone on the top of its snout, and the single rounded horn on the roof of its skull, which was originally mistaken for the dome of a pachycephalosaur. It also had more teeth in both upper and lower jaws than most abelisaurids.

Known from several well-preserved skulls and abundant skeletal material, Majungasaurus has recently become one of the best-studied theropod dinosaurs from the Southern Hemisphere. It appears to be most closely related to abelisaurids from India rather than South America or continental Africa, a fact which has important biogeographical implications. Majungasaurus was the apex predator in its ecosystem, mainly preying on sauropods like Rapetosaurus, and is also the only dinosaur for which direct evidence of cannibalism is known.

Marsh rice rat
The marsh rice rat (Oryzomys palustris) is a semiaquatic North American rodent in the family Cricetidae. It is found mostly in the eastern and southern United States, from New Jersey and Kansas south to Florida and northeasternmost Tamaulipas, Mexico; its range previously extended further west and north, where it may have been a commensal in corn-cultivating communities. It usually occurs in wet habitats such as swamps and saltmarshes. Weighing about 40 to 80 g (1.4 to 2.8 oz), the marsh rice rat is a medium-sized rodent that resembles the common black and brown rat. The upperparts are generally gray-brown, but reddish in many Florida populations. The feet show several specializations for life in the water. The skull is large and flattened and is short at the front.

John Bachman discovered the marsh rice rat in 1816, and it was formally described in 1837. Several subspecies have been described since the 1890s, mainly from Florida, but there is disagreement over their validity. The Florida Keys population is sometimes classified as a different species, the silver rice rat (Oryzomys argentatus). Data from the mitochondrial cytochrome b gene indicate a deep divergence between populations east of Mississippi and those further west, which suggests that the western populations may be recognized as a separate species, Oryzomys texensis. The species is part of the genus Oryzomys, which also includes several others occurring further south in Mexico, Central America, and northwestern South America, some of which have previously been regarded as subspecies of the marsh rice rat. One, Oryzomys couesi, occurs with the marsh rice rat in Tamaulipas and southern Texas.

The marsh rice rat is active during the night, makes nests of sedge and grass, and occasionally builds runways. It has a diverse diet that includes plants, fungi, and a variety of animals. Population densities are usually below 10 per ha (4 per acre) and home ranges vary from 0.23 to 0.37 ha (0.57 to 0.91 acres), depending on sex and geography. Litters of generally three to five young are born after a pregnancy of about 25 days, mainly during the summer. Newborns are helpless at birth, but are weaned after a few weeks. Several animals prey on the marsh rice rat, including the barn owl, and it usually lives for less than a year in the wild. It is infected by many different parasites and harbors a hantavirus that also infects humans. The species is not of conservation concern, but some populations are threatened.

Marwari
The Marwari or Malani is a rare breed of horse from the Marwar (or Jodhpur) region of India. Known for its inward-turning ear tips, it comes in all equine colours, although pinto patterns tend to be the most popular with buyers and breeders. It is known for its hardiness, and is quite similar to the Kathiawari, another Indian breed from the Kathiawar region southwest of Marwar. Many breed members exhibit a natural ambling gait. The Marwari are descended from native Indian ponies crossed with Arabian horses, possibly with some Mongolian influence.

The Rathores, traditional rulers of the Marwar region of western India, were the first to breed the Marwari. Beginning in the 12th century, they espoused strict breeding that promoted purity and hardiness. Used throughout history as a cavalry horse by the people of the Marwar region, the Marwari was noted for its loyalty and bravery in battle. The breed deteriorated in the 1930s, when poor management practices resulted in a reduction of the breeding stock, but today has regained some of its popularity. The Marwari is used for light draught and agricultural work, as well as riding and packing. In 1995, a breed society was formed for the Marwari in India, and in the 2000s horses have begun to be exported to the United States and Europe.

Massospondylus
Massospondylus (, from Greek, μάσσων (massōn, "longer") and σπόνδυλος (spondylos, "vertebra") is a genus of prosauropod dinosaur from the early Jurassic Period (Hettangian to Pliensbachian ages, ca. 200–183 million years ago). It was described by Sir Richard Owen in 1854 from remains found in South Africa, and is thus one of the first dinosaurs to have been named. Fossils have since been found at other locations in South Africa, Lesotho, and Zimbabwe. Further material from Arizona's Kayenta Formation, India, and Argentina has been assigned to this genus, but may not belong to Massospondylus.

The type species is M. carinatus; seven other species have been named during the past 150 years, but only M. kallae among these is still considered valid. Prosauropod systematics have undergone numerous revisions during the last several years, and many scientists disagree where exactly Massospondylus lies on the dinosaur evolutionary tree. The family name Massospondylidae was once coined for the genus, but because knowledge of prosauropod relationships is in a state of flux, it is unclear which other dinosaurs—if any—belong in a natural grouping of massospondylids; several 2007 papers support the family's validity.

Although Massospondylus was long depicted as quadrupedal, a 2007 study found it to be bipedal. It was probably a plant eater (herbivore), although it is speculated that the prosauropods may have been omnivorous. This animal, 4–6 meters (13–20 feet) long, had a long neck and tail, with a small head and slender body. On each of its forefeet, it bore a sharp thumb claw that was used in defense or feeding. Recent studies indicate Massospondylus grew steadily throughout its lifespan, possessed air sacs similar to those of birds, and may have cared for its young.

Metabolism
Metabolism is the set of chemical reactions that happen in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. Anabolism uses energy to construct components of cells such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, by a sequence of enzymes. Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy and will not occur by themselves, by coupling them to spontaneous reactions that release energy. As enzymes act as catalysts they allow these reactions to proceed quickly and efficiently. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.

The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the metabolic rate, also influences how much food an organism will require.

A striking feature of metabolism is the similarity of the basic metabolic pathways and components between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all organisms, being found in species as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants. These striking similarities in metabolism are probably due to the high efficiency of these pathways, and their early appearance in evolutionary history.

Nuthatches
The nuthatches are a genus, Sitta, of small passerine birds belonging to the family Sittidae. Characterised by large heads, short tails, and powerful bills and feet, nuthatches advertise their territory using loud, simple songs. Most species exhibit grey or bluish upperparts and a black eye stripe.

Most nuthatches breed in the temperate or montane woodlands of the Northern Hemisphere, although two species have adapted to rocky habitats in the warmer and drier regions of Eurasia. However, the greatest diversity is in Southern Asia, and similarities between the species have made it difficult to identify distinct species. All members of this genus nest in holes or crevices. Most species are non-migratory and live in their habitat year-round, although the North American Red-breasted Nuthatch migrates to warmer regions during the winter. A few nuthatch species have restricted ranges and face threats from deforestation.

Nuthatches are omnivorous, eating mostly insects, nuts and seeds. They forage for insects hidden in or under bark by climbing along tree trunks and branches, sometimes upside-down. They forage within their territories when breeding, but may join mixed feeding flocks at other times. Their habit of wedging a large food item in a crevice and then hacking at it with their strong bills gives this group its English name.

Ocean sunfish
The ocean sunfish, Mola mola, or common mola, is the heaviest known bony fish in the world. It has an average adult weight of 1000 kg. The species is native to tropical and temperate waters around the globe. It resembles a fish head with a tail, and its main body is flattened laterally. Sunfish can be as tall as they are long when their dorsal and ventral fins are extended.

Sunfish live on a diet that consists mainly of jellyfish, but because this diet is nutritionally poor, they consume large amounts in order to develop and maintain their great bulk. Females of the species can produce more eggs than any other known vertebrate. Sunfish fry resemble miniature pufferfish, with large pectoral fins, a tail fin and body spines uncharacteristic of adult sunfish.

Adult sunfish are vulnerable to few natural predators, but sea lions, orcas and sharks will consume them. Among humans, sunfish are considered a delicacy in some parts of the world, including Japan, the Korean peninsula and Taiwan, but sale of their flesh is banned in the European Union. Sunfish are frequently, though accidentally, caught in gillnets, and are also vulnerable to harm or death from encounters with floating trash, such as plastic bags.

A member of the order Tetraodontiformes, which also includes pufferfish, porcupinefish and filefish, the sunfish shares many traits common to members of this order. It was originally classified as Tetraodon mola under the pufferfish genus, but it has since been given its own genus, Mola, with two species under it. The ocean sunfish, Mola mola, is the type species of the genus.

Oceanic whitetip shark
The oceanic whitetip shark, Carcharhinus longimanus, is a large pelagic shark inhabiting tropical and warm temperate seas. Its stocky body is most notable for its long, white-tipped, rounded fins.

This aggressive but slow-moving fish dominates feeding frenzies. Recent studies show  steeply declining populations because its large fins are highly valued as the chief ingredient of shark fin soup and, as with other shark species, the whitetip faces mounting fishing pressure throughout its range.

Olm
The Olm, or Proteus (Proteus anguinus), is a blind amphibian endemic to the subterranean waters of caves of the Dinaric karst of southern Europe. It lives in the waters that flow underground through this extensive limestone region including waters of the Soča river basin near Trieste in Italy, through to southern Slovenia, southwestern Croatia, and Herzegovina. The olm is the only species in its genus Proteus, the only European species of the family Proteidae, and the only European exclusively cave-dwelling chordate. It is also occasionally called the "human fish" by locals because of its skin color, similar to that of white people (translated literally from človeška ribica and čovječja ribica), as well as "cave salamander" or "white salamander." In Slovenia it is also known by the name močeril, which translates as "the one that burrows into wetness."

This animal is most notable for its adaptations to a life of complete darkness in its underground habitat. The olm's eyes are undeveloped, leaving it blind, while its other senses, particularly those of smell and hearing, are acutely developed. It also lacks any pigmentation in its skin. In contrast to most amphibians, the olm is entirely aquatic, and it eats, sleeps, and breeds underwater. It has 3 toes on its forelimbs, but 2 toes on its hind feet. It also exhibits neoteny, retaining larval characteristics like external gills into adulthood, like the American amphibians, the axolotl and the mud puppy.

Oryzomys
Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions. The taxonomic history of the species has been eventful, and most were at one time included in the marsh rice rat; additional species may be recognized in the future. The name Oryzomys was established in 1857 by Spencer Fullerton Baird for the marsh rice rat and was soon applied to over a hundred species of American rodents. Subsequently, the genus gradually became more narrowly defined until its current contents were established in 2006, when ten new genera were established for species previously placed in Oryzomys.

Species of Oryzomys are medium-sized rats with long, coarse fur. The upperparts are gray to reddish and the underparts white to buff. The animals have broad feet without complete ungual tufts of hair around the claws and, in at least some species, with webbing between the toes. The rostrum (front part of the skull) is broad and the braincase is high. Both the marsh rice rat and O. couesi have 56 chromosomes, lack a gall bladder, and have a complex penis (as is characteristic of the Sigmodontinae) with some traits that are rare among oryzomyines; these characters are unknown in the other species.

The habitat includes various kinds of wetlands, such as lakes, marshes, and rivers. Oryzomys species swim well, are active during the night, and eat both plant and animal food. They build woven nests of vegetation. After a gestation period of 21 to 28 days, about four young are born. Species of Oryzomys are infected by numerous parasites and carry at least three hantaviruses, one of which (Bayou virus) also infects humans. Two, perhaps three, species have gone extinct over the last two centuries and at least one other is endangered, but the widespread marsh rice rat and O. couesi are not threatened.

Oryzomys couesi
Oryzomys couesi, also known as Coues' Rice Rat, is a semiaquatic rodent in the family Cricetidae occurring from southernmost Texas through Mexico and Central America into northwestern Colombia. It is usually found in wet habitats, such as marshes, but also lives in drier forests and shrublands. Weighing about 43 to 82 g (1.5 to 2.9 oz), O. couesi is a medium-sized to large rat. The coarse fur is buff to reddish above and white to buff below. The hindfeet show some specializations for life in the water, such as reduced ungual tufts of hair around the digits. It has 56 chromosomes. There is much geographic variation in size, proportions, color, and skull features. Oryzomys couesi is active during the night and builds nests of vegetation that are suspended among reeds about 1 m (3 ft) above the ground. It is an excellent swimmer and dives well, but can also climb in vegetation. An omnivore, it eats both plant and animal food, including seeds and insects. It breeds throughout the year; females give birth to about four young after a pregnancy of 21 to 28 days. The species may be infected by several different parasites and by two hantaviruses.

The species was first described in 1877, the first of many related species from the region described until the 1910s. In 1918, Edward Alphonso Goldman consolidated most into the single species Oryzomys couesi and in 1960 Raymond Hall united this taxon with its United States relative, the marsh rice rat (O. palustris), into a single widespread species; subsequently, many related, localized species retained by Goldman were also included in this taxon. After studies of the contact zone in Texas, where O. couesi and the marsh rice rat meet, were published in 1979 and underscored the distinctness of the two, they were again regarded as separate. Since then, some of the peripheral forms of the group, such as Oryzomys antillarum from Jamaica and Oryzomys peninsulae from the Baja California Peninsula, have been reinstated as species. Nevertheless, O. couesi as currently constituted is likely a composite of several species; a 2010 study, using DNA sequence data, found evidence to recognize separate species from the Pacific and eastern sides of the distribution of O. couesi and two additional species from Panama and Costa Rica. Generally, Oryzomys couesi is common and of no conservation concern, and it is even considered a plague species in places, but some populations are threatened.

Oryzomys dimidiatus
Oryzomys dimidiatus, also known as the Nicaraguan Oryzomys, Thomas's Rice Rat, or Nicaraguan Rice Rat, is a rodent in the genus Oryzomys of the family Cricetidae. It is known from only three specimens, all collected in southeastern Nicaragua since 1904. Placed in Nectomys upon its discovery, it was later classified in its own subgenus of Oryzomys and finally recognized as closely related to other species now placed in Oryzomys, including the marsh rice rat and Oryzomys couesi, which occurs in the same region.

With a head and body length of 110 to 128 mm (4.3 to 5.0 in), Oryzomys dimidiatus is a medium-sized rice rat. The upperparts are gray-brown and the underparts are grayish, not buffy as in O. couesi. The tail is only slightly darker above than below. All three specimens were caught near water and the species may be semiaquatic, spending some time in the water. Its conservation status is currently assessed as "Least Concern".

Oryzomys gorgasi
Oryzomys gorgasi, also known as Gorgas's Oryzomys or Gorgas's Rice Rat, is a rodent in the genus Oryzomys of family Cricetidae. First collected as a living animal in 1967, it is known from only a few localities, including a freshwater swamp in the lowlands of northwestern Colombia and a mangrove islet in northwestern Venezuela. It formerly occurred on the island of Curaçao off northwestern Venezuela; this extinct population has been described as a separate species, Oryzomys curasoae, but does not differ morphologically from mainland populations.

Oryzomys gorgasi is a medium-sized, brownish species with large, semiaquatically specialized feet. It differs from other Oryzomys species in several features of its skull. Its diet includes crustaceans, insects, and plant material, and parasitic nematodes infect it. The species is listed as "Endangered" by the International Union for Conservation of Nature due to destruction of its habitat and competition with the introduced black rat (Rattus rattus).

Pallid sturgeon
The Pallid sturgeon (Scaphirhynchus albus) is an endangered species of ray-finned fish, endemic to the waters of the Missouri and lower Mississippi River basins of the United States. Named for its pale coloration, the Pallid sturgeon is closely related to the relatively common shovelnose sturgeon (Scaphirhyncus platorhynchus), but is much larger, averaging between 30 and 60 in in length and 85 lb in weight at maturity. The Pallid sturgeon takes 15 years to mature and spawns infrequently, but can live for up to a century. A member of the Acipenseridae (sturgeon) family of fish that originated during the Cretaceous period 70 million years ago, the Pallid sturgeon has remained essentially unchanged. The species is considered to be a relic of the dinosaur era, and has been called "one of the ugliest fish in North America".

In 1990, the U.S. Fish and Wildlife Service (USFWS) placed the Pallid sturgeon on the endangered species list, because few young individuals had been observed in the preceding decade, and sightings had greatly diminished; the species is now rarely seen in the wild. It was the first fish species in the Mississippi River drainage area to be listed as endangered, and a loss of its habitat is thought to be responsible for its decline. The vast majority of the Mississippi River drainage system has been channeled and dammed, reducing the gravel deposits and slow-moving side channels that are its favored spawning areas. Until the middle of the 20th century, the Pallid sturgeon was common and anglers found catching such a large fish in fresh water a rewarding experience. The species is considered to be good-tasting, and its eggs have been used as caviar, although less commonly than those of many other sturgeon.

Efforts to prevent the species from becoming extinct have had modest success. Pallid sturgeon are actively being raised in a dozen hatcheries and the offspring are being released back to the wild every year. To better understand Pallid sturgeon behavior, researchers have implanted GPS transmitters to track their movements and help identify possible spawning areas. Federal and state agencies are working together to improve habitat by restoring spawning areas since restoration of these areas is required if the species is to survive in the wild.

Panellus stipticus
Panellus stipticus, commonly known as the bitter oyster, the astringent panus, the luminescent panellus, or the stiptic fungus, is a species of fungus in the Mycenaceae family, and the type species of the genus Panellus. A common and widely distributed species, it is found in Asia, Australasia, Europe, and North America, where it grows in groups or dense overlapping clusters on the logs, stumps, and trunks of deciduous trees, especially beech, oak, and birch. During the development of the fruit bodies, the mushrooms start out as tiny white knobs, which, over a period of one to three months, develop into fan- or kidney-shaped caps that measure up to 3 cm broad. The caps are orange-yellow to brownish, and attached to the decaying wood by short stubby stalks that are connected off-center or on the side of the caps. The fungus was given its current scientific name in 1879, but has been known by many names since French mycologist Jean Bulliard first described it as Agaricus stypticus in 1783. Molecular phylogenetic analysis revealed P. stipticus to have a close genetic relationship with members of the genus Mycena.

Panellus stipticus is one of several dozen species of fungi that are bioluminescent. Strains from eastern North America are typically bioluminescent, but those from the Pacific regions of North America and from other continents are not. The luminescence is localized to the edges of the gills and the junction of the gills with the stem and cap. Bioluminescence is also observable with mycelia grown in laboratory culture, and the growth conditions for optimal light production have been studied in detail. Several chemicals have been isolated and characterized that are believed to be responsible for light production. Genetic analysis has shown that luminescence is controlled by a single dominant allele. The luminescent glow of this and other fungi inspired the term foxfire, coined by early settlers in eastern and southern North America. Modern research has probed the potential of P. stipticus as a tool in bioremediation, due to its ability to detoxify various environmental pollutants.

Parasaurolophus
Parasaurolophus (, commonly also ; meaning "near crested lizard" in reference to Saurolophus) is a genus of ornithopod dinosaur from the Late Cretaceous Period of what is now North America, about 76-73 million years ago. It was a herbivore that walked both as a biped and a quadruped. Three species are recognized: P. walkeri (the type species), P. tubicen, and the short-crested P. cyrtocristatus. Remains are known from Alberta (Canada), and New Mexico and Utah (USA). It was first described in 1922 by William Parks from a skull and partial skeleton in Alberta.

Parasaurolophus is a hadrosaurid, part of a diverse family of Cretaceous dinosaurs known for their range of bizarre head adornments. This genus is known for its large, elaborate cranial crest, which at its largest forms a long curved tube projecting upwards and back from the skull. Charonosaurus from China, which may have been its closest relative, had a similar skull and potentially a similar crest. The crest has been much discussed by scientists; the consensus is that major functions included visual recognition of both species and sex, acoustic resonance, and thermoregulation. It is one of the rarer duckbills, known from only a handful of good specimens.

Peregrine Falcon
The Peregrine Falcon (Falco peregrinus), also known as the Peregrine, and historically as the "Duck Hawk" in North America, is a cosmopolitan bird of prey in the family Falconidae. It is a large, crow-sized falcon, with a blue-gray back, barred white underparts, and a black head and "moustache". It can reach speeds over 320 km/h in a stoop, making it one of the fastest creatures on the planet. As is common with bird-eating raptors, the female is much bigger than the male. Experts recognize 17 to 19 subspecies which vary in appearance and range; there is disagreement over whether the distinctive Barbary Falcon is a subspecies or a distinct species.

The Peregrine's breeding range includes land regions from the Arctic tundra to the Tropics. It can be found nearly everywhere on Earth, except extreme polar regions, very high mountains, and most tropical rainforests; the only major ice-free landmass from which it is entirely absent is New Zealand. This fact makes it the world's most widespread bird of prey. Both the English and scientific names of this species mean "wandering falcon", referring to the migratory habits of many northern populations.

While its diet consists almost exclusively of medium-sized birds, the Peregrine will occasionally hunt small mammals, small reptiles or even insects. Reaching sexual maturity at one year, it mates for life and nests in a scrape, normally on cliff edges or, in recent times, on tall human-made structures. The Peregrine Falcon became an endangered species in many areas due to the use of pesticides, especially DDT. Since the ban on DDT from the beginning of the 1970s onwards, the populations recovered, supported by large scale protection of nesting places and releases to the wild.

Phagocytes
Phagocytes are the white blood cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are essential for fighting infections and for subsequent immunity. Phagocytes are important throughout the animal kingdom and are highly developed within vertebrates. One litre of human blood contains about six billion phagocytes. Phagocytes were first discovered in 1882 by Ilya Ilyich Mechnikov while he was studying starfish larvae. Mechnikov was awarded the 1908 Nobel Prize in Physiology or Medicine for his discovery. Phagocytes occur in many species; some amoebae behave like macrophage phagocytes, which suggests that phagocytes appeared early in the evolution of life.

Phagocytes of humans and other animals are called "professional" or "non-professional" depending on how effective they are at phagocytosis. The professional phagocytes include cells called neutrophils, monocytes, macrophages, dendritic cells, and mast cells. The main difference between professional and non-professional phagocytes is that the professional phagocytes have molecules called receptors on their surfaces that can detect harmful objects, such as bacteria, that are not normally found in the body. Phagocytes are crucial in fighting infections, as well as in maintaining healthy tissues by removing dead and dying cells that have reached the end of their lifespan.

During an infection, chemical signals attract phagocytes to places where the pathogen has invaded the body. These chemicals may come from bacteria or from other phagocytes already present. The phagocytes move by a method called chemotaxis. When phagocytes come into contact with bacteria, the receptors on the phagocyte's surface will bind to them. This binding will lead to the engulfing of the bacteria by the phagocyte. Some phagocytes kill the ingested pathogen with oxidants and nitric oxide. After phagocytosis, macrophages and dendritic cells can also participate in antigen presentation, a process in which a phagocyte moves parts of the ingested material back to its surface. This material is then displayed to other cells of the immune system. Some phagocytes then travel to the body's lymph nodes and display the material to white blood cells called lymphocytes. This process is important in building immunity. However, many pathogens have evolved methods to evade attacks by phagocytes.

Pied Currawong
The Pied Currawong (Strepera graculina) is a medium-sized black passerine bird native to eastern Australia and Lord Howe Island. One of three currawong species in the genus Strepera, it is closely related to the butcherbirds and Australian Magpie of the family Artamidae. Six subspecies are recognised. It is a robust crow-like bird averaging around 48 cm in length, black or sooty grey-black in plumage with white undertail and wing patches, yellow irises, and a heavy bill. The male and female are similar in appearance. Known for its melodious calls, the species' name currawong is of indigenous origin.

Within its range, the Pied Currawong is generally sedentary, although populations at higher altitudes relocate to lower areas during the cooler months. It is omnivorous, with a diet that includes a wide variety of berries and seeds, invertebrates, bird eggs and juvenile birds. It is a predator which has adapted well to urbanization and can be found in parks and gardens as well as rural woodland. The habitat includes all kinds of forested areas, although mature forests are preferred for breeding. Roosting, nesting and the bulk of foraging take place in trees, in contrast with the ground foraging behaviour of its relative the Australian Magpie.

Pinguicula moranensis
Pinguicula moranensis is a perennial rosette-forming insectivorous herb native to Mexico and Guatemala. A species of butterwort, it forms summer rosettes of flat, succulent leaves up to 10 centimeters (4 in) long, which are covered in mucilagenous (sticky) glands that attract, trap, and digest arthropod prey. Nutrients derived from the prey are used to supplement the nutrient-poor substrate that the plant grows in. In the winter the plant forms a non-carnivorous rosette of small, fleshy leaves that conserves energy while food and moisture supplies are low. Single pink, purple, or violet flowers appear twice a year on upright stalks up to 25 centimeters long.

The species was first collected by Humboldt and Bonpland on the outskirts of Mina de Morán in the Sierra de Pachuca of the modern-day Mexican state of Hidalgo on their Latin American expedition of 1799–1804. Based on these collections, Humboldt, Bonpland and Carl Sigismund Kunth described this species in Nova Genera et Species Plantarum in 1817. The extremely variable species has been redefined at least twice since, while several new species have been segregated from it based on various geographical or morphological distinctions, although the legitimacy of some of these is still debated. P. moranensis remains the most common and most widely distributed member of the Section Orcheosanthus. It has long been cultivated for its carnivorous nature and attractive flowers, and is one of the most common butterworts in cultivation.

The generic name Pinguicula is derived from the Latin pinguis (meaning "fat") due to the buttery texture of the surface of the carnivorous leaves. The specific epithet moranensis refers to its type location, Mina de Moran.

Pipistrellus raceyi
Pipistrellus raceyi, also known as Racey's pipistrelle bat, is a bat from Madagascar, in the genus Pipistrellus. Although unidentified species of Pipistrellus had been previously reported from Madagascar since the 1990s, P. raceyi was not formally named until 2006. It is apparently most closely related to the Asian species P. endoi, P. paterculus, and P. abramus, and its ancestors probably reached Madagascar from Asia. P. raceyi has been recorded at four sites, two in the eastern and two in the western lowlands. In the east, it is found in open areas and has been found roosting in a building; in the west it occurs in dry forest. Because of uncertainties about its ecology, it is listed as "Data Deficient" on the IUCN Red List.

With a forearm length of 28.0 to 31.2 mm (1.10 to 1.23 in), Pipistrellus raceyi is small to medium-sized for a species of Pipistrellus. The body is reddish above and yellow-brown below. The wings are dark and the feet are small. Males have a long penis and baculum (penis bone), which is somewhat similar to those of P. endoi, P. abramus and P. paterculus. In the skull, the rostrum (front part) is less flat than in related species and the supraorbital ridges (above the eyes) are prominent. The fourth upper premolar does not touch the upper canine and the second lower premolar is well-developed.

Platypus
The Platypus (Ornithorhynchus anatinus) is a semi-aquatic mammal endemic to eastern Australia, including Tasmania. Together with the four species of echidna, it is one of the five extant species of monotremes, the only mammals that lay eggs instead of giving birth to live young. It is the sole living representative of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species have been found in the fossil record.

The bizarre appearance of this egg-laying, venomous, duck-billed, beaver-tailed, otter-footed mammal baffled European naturalists when they first encountered it, with some considering it an elaborate fraud. It is one of the few venomous mammals; the male Platypus has a spur on the hind foot that delivers a venom capable of causing severe pain to humans. The unique features of the Platypus make it an important subject in the study of evolutionary biology and a recognisable and iconic symbol of Australia; it has appeared as a mascot at national events and is featured on the reverse of the Australian 20 cent coin. The Platypus is the animal emblem of the state of New South Wales.

Until the early 20th century it was hunted for its fur, but it is now protected throughout its range. Although captive breeding programmes have had only limited success and the Platypus is vulnerable to the effects of pollution, it is not under any immediate threat.

Plesiorycteropus
Plesiorycteropus, also known as the bibymalagasy or Malagasy aardvark, is a recently extinct eutherian mammalian genus from Madagascar. Upon its description in 1895, it was classified with the aardvark, but recent studies have found little evidence to link it to aardvarks or any other order of mammals. Therefore, it is now placed in its own order, Bibymalagasia, which may be part of Afrotheria. Two species are currently recognized, the larger P. madagascariensis and the smaller P. germainepetterae. They probably overlapped in distribution, as subfossil remains of both species have been found in the same site.

Knowledge of the skeletal anatomy is limited, as only limb and partial pelvis and skull bones have been recovered to date. Plesiorycteropus was probably a digging animal that fed on insects such as termites and ants. It also shows adaptations for climbing and sitting. Estimates of its mass range from 6 to 18 kg (13 to 40 lb). Why and when it became extinct remains unknown; one bone has been radiocarbon dated to 200 BCE and forest destruction by humans may have contributed to its extinction.

Polyozellus
Polyozellus is a genus of fungi in the Thelephoraceae family, a grouping of mushrooms known collectively as the leathery earthfans. A monotypic genus, it contains the single species Polyozellus multiplex, first described in 1899, and commonly known as the blue chanterelle, the clustered blue chanterelle, or, in Alaska, the black chanterelle. The distinctive fruit body of this species resembles blue- to purple-colored clusters of vase- or spoon-shaped caps with veiny wrinkles on the undersurface that run down the length of the stem.

Polyozellus has had a varied taxonomic history and has been reclassified several times at both the family and genus level. The range of Polyozellus includes North America and eastern Asia, where P. multiplex may be found growing on the ground in coniferous forests, usually under spruce and fir trees. It is an edible species, and has been harvested for commercial purposes. Polyozellus multiplex contains the bioactive compound polyozellin, shown to have various physiological properties, including suppressive effects on stomach cancer.

Porbeagle
The porbeagle (Lamna nasus) is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent is the closely related salmon shark (L. ditropis). The porbeagle typically reaches 2.5 m in length and a weight of 135 kg; North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. Gray above and white below, the porbeagle has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail. It has large pectoral and first dorsal fins, tiny pelvic, second dorsal, and anal fins, and a crescent-shaped caudal fin. The most distinctive features of this species are its three-cusped teeth, the white blotch on the back of its first dorsal fin, and the two pairs of lateral keels on its tail.

Preying mainly on bony fishes and cephalopods, the porbeagle is an opportunistic hunter that regularly moves up and down in the water column, catching prey in midwater as well as off the bottom. It is most commonly found over food-rich banks on the outer continental shelf, but does make occasional forays close to shore or into the open ocean, down to a depth of 1360 m. It also conducts long-distance seasonal migrations, generally shifting between shallower and deeper water. The porbeagle is fast and highly active, with physiological adaptations that enable it to maintain a higher body temperature than the surrounding water. It can be solitary or gregarious, and has been known to perform seemingly playful behavior. This shark is aplacental viviparous with oophagy, meaning that the developing embryos are retained within the mother's uterus and subsist on non-viable eggs. Females typically bear four pups every year.

Only a few shark attacks of uncertain provenance have been attributed to the porbeagle. It is well-regarded as a game fish by recreational anglers. The meat and fins of the porbeagle are highly valued, which has led to a long history of intense human exploitation. However, this species cannot sustain heavy fishing pressure due to its low reproductive capacity. Direct commercial fishing for the porbeagle, principally by Norwegian longliners, led to stock collapses in the eastern North Atlantic in the 1950s, and the western North Atlantic in the 1960s. The porbeagle continues to be caught throughout its range, both intentionally and as bycatch, with varying degrees of monitoring and management. The International Union for Conservation of Nature (IUCN) has assessed the porbeagle as Vulnerable worldwide, and as either Endangered or Critically Endangered in different parts of its northern range.

Primate
A primate (, US dict: prī′·māt) is a member of the biological order Primates ( prī·mā′·tēz; Latin: "prime, first rank" ), the group that contains prosimians (including lemurs, lorises, galagos and tarsiers ) and  simians (monkeys and apes). With the exception of humans, who inhabit every continent on Earth, most primates live in tropical or subtropical regions of the Americas, Africa and Asia. Primates range in size from the Madame Berthe's Mouse Lemur, which weighs only 30 g to the Mountain Gorilla weighing 200 kg. According to fossil evidence, the primitive ancestors of primates may have existed in the late Cretaceous period around 65 million years ago, and the oldest known primate is the Late Paleocene Plesiadapis, c. 55–58 million years ago. Molecular clock studies suggest that the primate branch may be even older, originating in the mid-Cretaceous period around 85 mya.

The Primates order has traditionally been divided into two main groupings: prosimians and simians. Prosimians have characteristics most like those of the earliest primates, and included the lemurs of Madagascar, lorisiforms and tarsiers. Simians included the monkeys and apes. More recently, taxonomists have created the suborder Strepsirrhini, or curly-nosed primates, to include non-tarsier prosimians and the suborder Haplorrhini, or dry-nosed primates, to include tarsiers and the simians. Simians are divided into two groups: the platyrrhines ("flat nosed") or New World monkeys of South and Central America and the catarrhine (narrow nosed) monkeys of Africa and southeastern Asia. The New World monkeys include the capuchin, howler and squirrel monkeys, and the catarrhines include the Old World monkeys (such as baboons and macaques) and the apes. Humans are the only catarrhines that have spread successfully outside of Africa, South Asia, and East Asia, although fossil evidence shows many species once existed in Europe as well.

Considered generalist mammals, primates exhibit a wide range of characteristics. Some primates (including some great apes and baboons) do not live primarily in trees, but all species possess adaptations for climbing trees. Locomotion techniques used include leaping from tree to tree, walking on two or four limbs, knuckle-walking, and swinging between branches of trees (known as brachiation). Primates are characterized by their large brains, relative to other mammals, as well as an increased reliance on stereoscopic vision at the expense of smell, the dominant sensory system in most mammals. These features are most significant in monkeys and apes, and noticeably less so in lorises and lemurs. Three-color vision has developed in some primates. Most also have opposable thumbs and some have prehensile tails. Many species are sexually dimorphic, which means males and females have different physical traits, including body mass, canine tooth size, and coloration. Primates have slower rates of development than other similarly sized mammals, and reach maturity later but have longer lifespans. Some species live in solitude, others live in male–female pairs, and others live in groups of up to hundreds of members.

Procellariidae
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes (or tubenoses), which also includes the albatrosses, the storm-petrels, and the diving petrels.

The procellariids are the most numerous family of tubenoses, and the most diverse. They range in size from the giant petrels, which are almost as large as the albatrosses, to the prions, which are as small as the larger storm-petrels. They feed on fish, squid and crustacea, with many also taking fisheries discards and carrion. All species are accomplished long-distance foragers, and many undertake long trans-equatorial migrations. They are colonial breeders, exhibiting long-term mate fidelity and site philopatry. In all species, each pair lays a single egg per breeding season. Their incubation times and chick-rearing periods are exceptionally long compared to other birds.

Many procellariids have breeding populations of over several million pairs; others number fewer than 200 birds. Humans have traditionally exploited several species of fulmar and shearwater (known as muttonbirds) for food, fuel, and bait, a practice that continues in a controlled fashion today. Several species are threatened by introduced species attacking adults and chicks in breeding colonies and by long-line fisheries.

Proteasomes
Proteasomes are very large protein complexes inside all eukaryotes and archaea, as well as in some bacteria. In eukaryotes, they are located in the nucleus and the cytoplasm. The main function of the proteasome is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that carry out such reactions are called proteases. Proteasomes are part of a major mechanism by which cells regulate the concentration of particular proteins and degrade misfolded proteins. The degradation process yields peptides of about seven to eight amino acids long, which can then be further degraded into amino acids and used in synthesizing new proteins. Proteins are tagged for degradation with a considerably small protein called ubiquitin. The tagging reaction is catalyzed by enzymes called ubiquitin ligases. Once a protein is tagged with a single ubiquitin molecule, this is a signal to other ligases to attach additional ubiquitin molecules. The result is a polyubiquitin chain that is bound by the proteasome, allowing it to degrade the tagged protein.

In structure, the proteasome is a large barrel-like complex containing a "core" of four stacked rings around a central pore. Each ring is composed of seven individual proteins. The inner two rings are made of seven β subunits that contain the six protease active sites. These sites are located on the interior surface of the rings, so that the target protein must enter the central pore before it is degraded. The outer two rings each contain seven α subunits whose function is to maintain a "gate" through which proteins enter the barrel. These α subunits are controlled by binding to "cap" structures or regulatory particles that recognize polyubiquitin tags attached to protein substrates and initiate the degradation process. The overall system of ubiquitination and proteasomal degradation is known as the ubiquitin-proteasome system.

The proteasomal degradation pathway is essential for many cellular processes, including the cell cycle, the regulation of gene expression, and responses to oxidative stress. The importance of proteolytic degradation inside cells and the role of ubiquitin in proteolytic pathways was acknowledged in the award of the 2004 Nobel Prize in Chemistry to Aaron Ciechanover, Avram Hershko and Irwin Rose.

Pseudoryzomys simplex
Pseudoryzomys simplex, also known as the Brazilian False Rice Rat or False Oryzomys, is a species of rodent in the family Cricetidae from south-central South America. It is found in lowland palm savanna and thorn scrub habitats. It is a medium-sized species, weighing about 50 g, with gray–brown fur, long and narrow hindfeet, and a tail that is about as long as the head and body. The IUCN has assessed its conservation status as "Least Concern", although almost nothing is known of its diet or reproduction.

The only species in the genus Pseudoryzomys, its closest living relatives are the large rats Holochilus and Lundomys, which are semiaquatic, spending much of their time in the water. The three genera share several characters, including specializations towards a semiaquatic lifestyle, such as the presence of membranes between the digits (interdigital webbing), and a reduction in the complexity of the molar crowns, both of which are at incipient stages in Pseudoryzomys. Together, they form a unique assemblage within the oryzomyine tribe, a very diverse group including over one hundred species, mainly in South America. This tribe is part of the subfamily Sigmodontinae and family Cricetidae, which include many more species, mainly from Eurasia and the Americas. Pseudoryzomys simplex was independently described in 1887 on the basis of subfossil cave specimens from Brazil (as Hesperomys simplex) and in 1921 on the basis of a live specimen from Paraguay (as Oryzomys wavrini), and it was confirmed only in 1991 that both names in fact pertained to the same species.

Psittacosaurus
Psittacosaurus (, from the Greek for "parrot lizard") is a genus of psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period of what is now Asia, about 130 to 100 million years ago. It is notable for being the most species-rich dinosaur genus. At least ten extinct species are recognized from fossils found in different regions of modern-day China, Mongolia and Russia, with a possible additional species from Thailand.

All species of Psittacosaurus were gazelle-sized bipedal herbivores characterized by a high, powerful beak on the upper jaw. At least one species had long, quill-like structures on its tail and lower back, possibly serving a display function. Psittacosaurs were extremely early ceratopsians and, while they developed many novel adaptations of their own, they also shared many anatomical features with later ceratopsians, such as Protoceratops and the elephant-sized Triceratops.

Psittacosaurus is not as familiar to the general public as its distant relative Triceratops but it is one of the most completely known dinosaur genera. Fossils of over 400 individuals have been collected so far, including many complete skeletons. Most different age classes are represented, from hatchling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in the fossil record has led to its use as an index fossil for Early Cretaceous sediments of central Asia.

Puerto Rican Amazon
The Puerto Rican Amazon (Amazona vittata), also known as the Puerto Rican Parrot or Iguaca, is the only bird endemic to the archipelago of Puerto Rico belonging to the Neotropical genus Amazona. Measuring 28–30 cm (11–12 in), the Puerto Rican Amazon is a predominantly green parrot with a red forehead and white rings around the eyes. Two subspecies have been described, although there are doubts regarding the distinctiveness of the form gracilipes from Culebra Island, extinct since 1912. Its closest relatives are believed to be the Cuban Amazon (Amazona leucocephala) and the Hispaniolan Amazon (Amazona ventralis).

The Puerto Rican Amazon reaches sexual maturity between three and four years of age. It reproduces once a year and is a cavity nester. Once the female lays eggs she will remain in the nest and continuously incubate them until hatching. The chicks are fed by both parents and will fledge 60 to 65 days after hatching. This parrot's diet is varied and consists of flowers, fruits, leaves, bark and nectar obtained from the forest canopy.

The species is the only remaining native parrot in Puerto Rico and has been listed as critically endangered by the World Conservation Union since 1994. Once widespread and abundant, the population declined drastically in the 19th and early 20th centuries with the removal of most of its native habitat; the species completely vanished from Vieques and Mona Island, nearby to the main island of Puerto Rico. Conservation efforts commenced in 1968 to save the bird from extinction. In 2006, the total estimated population was 34 to 40 individuals in the wild and 143 individuals in captivity.

Pygmy hippopotamus
The pygmy hippopotamus (Choeropsis liberiensis or Hexaprotodon liberiensis) is a large mammal native to the forests and swamps of western Africa (the specific name liberiensis means "of Liberia", as this is where the vast majority live). The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the Hippopotamidae family, the other being its much larger cousin the common hippopotamus.

The pygmy hippopotamus displays many terrestrial adaptations, but like its larger cousin, it is semi-aquatic and relies on proximity to water to keep its skin moisturized and its body temperature cool. Behaviors such as mating and giving birth may occur in water or on land. The pygmy hippo is herbivorous, feeding on ferns, broad-leaved plants, grasses and fruits it finds in the forests.

A rare nocturnal forest creature, the pygmy hippopotamus is a difficult animal to study in the wild. Pygmy hippos were unknown outside of West Africa until the 19th century. Introduced to zoos in the early 20th century, they breed well in captivity and the vast majority of research is derived from zoo specimens. The survival of the species in captivity is more assured than in the wild: the World Conservation Union estimates that there are fewer than 3,000 pygmy hippos remaining in the wild. Pygmy hippos are primarily threatened by loss of habitat, as forests are logged and converted to farm land, and are also vulnerable to poaching, hunting, natural predators and war.

Raccoon
The raccoon (, Procyon lotor), sometimes spelled as racoon, also known as the common raccoon, North American raccoon, northern raccoon and colloquially as coon, is a medium-sized mammal native to North America. It is the largest of the procyonid family, having a body length of 40 to 70 cm and a body weight of 3+1/2 to 9 kg. The raccoon is usually nocturnal and is omnivorous, with a diet consisting of about 40% invertebrates, 33% plant foods, and 27% vertebrates. It has a grayish coat, of which almost 90% is dense underfur, which insulates against cold weather. Two of its most distinctive features are its extremely dexterous front paws and its facial mask, which are themes in the mythology of several Native American tribes. Raccoons are noted for their intelligence, with studies showing that they are able to remember the solution to tasks up to three years later.

The original habitats of the raccoon are deciduous and mixed forests of North America, but due to their adaptability they have extended their range to mountainous areas, coastal marshes, and urban areas, where many homeowners consider them to be pests. As a result of escapes and deliberate introductions in the mid-20th century, raccoons are now also distributed across the European mainland, the Caucasus region and Japan.

Though previously thought to be solitary, there is now evidence that raccoons engage in gender-specific social behavior. Related females often share a common area, while unrelated males live together in groups of up to four animals to maintain their positions against foreign males during the mating season and other potential invaders. Home range sizes vary anywhere from 3 hectares for females in cities to 50 km2 for males in prairies (7 acres to 20 sq mi). After a gestation period of about 65 days, two to five young (known as a "kit", plural "kits") are born in spring. The kits are subsequently raised by their mother until dispersion in late fall. Although captive raccoons have been known to live over 20 years, their average life expectancy in the wild is only 1.8 to 3.1 years. Hunting and traffic accidents are the two most common causes of death in many areas.

Red-backed Fairywren
The Red-backed Fairywren (Malurus melanocephalus) is a species of passerine bird in the Maluridae family. It is endemic to Australia and can be found near rivers and coastal areas along the northern and eastern coastlines from the Kimberley in the northwest to the Hunter Region in New South Wales. Like other fairywrens, this species displays marked sexual dimorphism. The male adopts a striking breeding plumage, with a black head and upperparts and tail, and brightly coloured red back and brown wings. The female has brownish upperparts and paler underparts. The male in eclipse plumage and the juvenile resemble the female. Some males remain in non-breeding plumage while breeding. Two subspecies are recognised; the nominate form melanocephalus of eastern Australia has a longer tail and orange back, and the short-tailed form cruentatus from northern Australia has a redder back.

The Red-backed Fairywren mainly eats insects, and supplements its diet with seed and small fruit. The preferred habitat is heathland and savannah, particularly where low shrubs and tall grasses provide cover. It can be nomadic in areas where there are frequent bushfires, although pairs or small groups of birds maintain and defend territories year-round in other parts of its range. Groups consist of a socially monogamous pair with one or more helper birds who assist in raising the young. These helpers are progeny that have attained sexual maturity yet remain with the family group for one or more years after fledging. The Red-backed Fairywren is sexually promiscuous, and each partner may mate with other individuals and even assist in raising the young from such pairings. Older males in breeding plumage are more likely to engage in this behaviour than are those breeding in eclipse plumage. As part of a courtship display, the male wren plucks red petals from flowers and displays them to females.

Red-billed Chough
The Red-billed Chough or Chough ( chuff), Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax. Its eight subspecies breed on mountains and coastal cliffs from Ireland and Great Britain east through southern Europe and North Africa to Central Asia, India and China.

This bird has glossy black plumage, a long curved red bill, red legs, and a loud, ringing call. It has a buoyant acrobatic flight with widely spread primaries. The Red-billed Chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It builds a wool-lined stick nest and lays three eggs. It feeds, often in flocks, on short grazed grassland, taking mainly invertebrate prey.

Although it is subject to predation and parasitism, the main threat to this species is changes in agricultural practices, which have led to population decline and range fragmentation in Europe; however, it is not threatened globally. The Red-billed Chough, which derived its common name from the Jackdaw, was formerly associated with fire-raising, and has links with Saint Thomas Becket and the county of Cornwall. The Red-billed Chough has been depicted on postage stamps of a few countries, including the Isle of Man, with four different stamps, and The Gambia where the bird does not occur.

Red-capped Robin
The Red-capped Robin (Petroica goodenovii) is a small passerine bird native to Australia. Found in dryer regions across much of the continent, it inhabits scrub and open woodland. Like many brightly coloured robins of the Petroicidae family, it is sexually dimorphic. Measuring 10.5–12.5 cm (4–5 in) in length, the robin has a small thin black bill, and dark brown eyes and legs. The male has a distinctive red cap and red breast, black upperparts, and a black tail with white tips. The underparts and shoulders are white. The female is an undistinguished grey-brown. This species uses a variety of songs, and males generally sing to advertise territories and attract females. Birds are encountered in pairs or small groups, but the social behaviour has been little studied.

The position of the Red-capped Robin and its Australian relatives on the passerine family tree is unclear; the Petroicidae are not closely related to either the European or American Robins but appear to be an early offshoot of the Passerida group of songbirds. The Red-capped Robin is a predominantly ground-feeding bird and its prey consists of insects and spiders. Although widespread, it is uncommon in much of its range and has receded in some areas from human activity.

Red-necked Grebe
The Red-necked Grebe, Podiceps grisegena, is a migratory aquatic bird that is found in the temperate regions of the northern hemisphere. Its wintering habitat is largely restricted to calm waters just beyond the waves around ocean coasts, although some birds may winter on large lakes. Grebes (sometimes called "helldivers" in North America) prefer shallow bodies of fresh water such as lakes, marshes or fish-ponds as breeding sites.

The Red-necked Grebe is a nondescript dusky-grey bird in winter. During the breeding season, it acquires the distinctive red neck plumage, black cap and contrasting pale grey face from which its name was derived. It also has an elaborate courtship display and a variety of loud mating calls. Once paired, it builds a nest from water plants on top of floating vegetation in a shallow lake or bog.

Like all grebes, the Red-necked is a good swimmer, a particularly swift diver, and responds to danger by diving rather than flying. The feet are positioned far back on the body, near the tail, which makes the bird ungainly on land. It dives for fish or picks insects off vegetation; it also swallows its own feathers, possibly to protect the digestive system. The conservation status of its two subspecies&mdash;P. g. grisegena found in Europe and western Asia, and the larger P. g. holboelii in North America and eastern Siberia&mdash;is evaluated as Least Concern, and the global population is stable or growing.

Red-tailed Black Cockatoo
The Red-tailed Black Cockatoo (Calyptorhynchus banksii), also known as Banksian- or Bank's Black Cockatoo, is a large cockatoo native to Australia. This species was known as Calyptorhynchus magnificus for many decades until the current scientific name was officially conserved in 1994. It is more common in the drier parts of the continent. Five subspecies are recognised, differing most significantly in beak size. Although the more northerly subspecies are widespread, the two southern subspecies, the Forest Red-tailed Black Cockatoo and the South-eastern Red-tailed Black Cockatoo are under threat.

Adult Red-tailed Black Cockatoos are around 60 centimetres (24 in) in length and sexually dimorphic. Males are completely black in colour, excepting their prominent red tail bands; the slightly smaller females are brownish-black with yellow barring and spotting and have yellow-orange tail stripes. The species is usually found in eucalyptus woodlands, or along water courses. In the more northerly parts of the country, these cockatoos are commonly seen in large flocks. They are seed eaters and cavity nesters. As such, they depend on trees with fairly large diameters, generally Eucalyptus. Populations in southeastern Australia are threatened by the reduction in forest cover and by other habitat alterations. Of the black cockatoos, the red-tailed black is the most adaptable to aviculture, although black cockatoos are much rarer and much more expensive outside Australia.

Red-winged Fairywren
The Red-winged Fairywren (Malurus elegans) is a species of passerine bird in the Maluridae family. It is sedentary and endemic to the southwestern corner of Western Australia. Exhibiting a high degree of sexual dimorphism, the male adopts a brilliantly coloured breeding plumage, with an iridescent silvery-blue crown, ear coverts and upper back, red shoulders, contrasting with a black throat, grey-brown tail and wings and pale underparts. Non-breeding males, females and juveniles have predominantly grey-brown plumage, though males may bear isolated blue and black feathers. No separate subspecies are recognised. Similar in appearance and closely related to the Variegated Fairywren (M. lamberti) and the Blue-breasted Fairywren (M. pulcherrimus), it is regarded as a separate species as no intermediate forms have been recorded where ranges overlap. Though the Red-winged Fairywren is locally common, there is evidence of a decline in numbers.

Bearing a narrow pointed bill adapted for probing and catching insects, the Red-winged Fairywren is primarily insectivorous; it forages and lives in the shelter of scrubby vegetation in temperate wetter forests dominated by the Karri (Eucalyptus marginata), remaining close to cover to avoid predators. Like other fairywrens, it is a cooperative breeding species, with small groups of birds maintaining and defending small territories year-round. Groups consist of a socially monogamous pair with several helper birds who assist in raising the young. There is a higher proportion of female helpers recorded for this species than for other species of fairywren. A variety of vocalisations and visual displays have been recorded for communication and courtship in this species. Singing is used to advertise territory, and birds can distinguish other individuals on song alone. Male wrens pluck yellow petals and display them to females as part of a courtship display.

Rhodotus
Rhodotus is a genus in the Physalacriaceae family of fungi. It is a monotypic genus and consists of the single mushroom species Rhodotus palmatus, known in the vernacular as the netted Rhodotus, the rosy veincap, or the wrinkled peach. This uncommon species has a circumboreal distribution, and has been collected in eastern North America, northern Africa, Europe, and Asia; declining populations in Europe have led to its appearance in over half of the European fungal Red Lists of threatened species. Typically found growing on the stumps and logs of rotting hardwoods, mature specimens may usually be identified by the pinkish color and the distinctive ridged and veined surface of their rubbery caps; variations in the color and quantity of light received during development lead to variations in the size, shape, and cap color of fruit bodies.

The unique characteristics of R. palmatus have made it difficult for taxonomists to agree on how it should be classified, resulting in an elaborate taxonomical history and an extensive synonymy. First named Agaricus palmatus by Bulliard in 1785, it was reclassified into several different genera before becoming Rhodotus in 1926. The familial placement of the genus Rhodotus within the order Agaricales has also been subject to dispute, and the taxon has been transferred variously to the families Amanitaceae, Entolomataceae, and Tricholomataceae. More recently, molecular phylogenetics analysis has helped determine that Rhodotus is most closely related to genera in the Physalacriaceae.

Right whales
Right whales are four species of large baleen whales consisting of two genera in the family Balaenidae of order Cetacea. Their bodies are very dark gray or black and rotund.

They are called "right whales" because whalers thought the whales were the "right" ones to hunt, as they float when killed and often swim within sight of shore. As such, they were nearly hunted to extinction during the active years of the whaling industry. Today, instead of hunting them, people often watch these acrobatic animals for pleasure.

Genetic evidence appears to have settled a long-standing question about whether to include the largest, the Arctic-dwelling bowhead whale, with the rest. All four are included in the taxonomic family Balaenidae, and all four are generally referred to as right whales. This article focuses on the three species of the genus Eubalaena.

Ring-tailed Lemur
The Ring-tailed Lemur (Lemur catta) is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of four lemur families. It is the only member of the Lemur genus. Like all lemurs it is endemic to the island of Madagascar. Known locally as Hira (Malagasy), Maky (Malagasy), or Maki (French), it inhabits gallery forests to spiny scrub in the southern regions of the island. It is omnivorous and the most terrestrial of lemurs. The animal is diurnal, being active exclusively in daylight hours.

The Ring-tailed Lemur is highly social, living in groups of up to 30 individuals. It is also female dominant, a trait common among lemurs. To keep warm and reaffirm social bonds, groups will huddle together forming a lemur ball. The Ring-tailed Lemur will also sunbathe, sitting upright facing its underside, with its thinner white fur towards the sun. Like other lemurs, this species relies strongly on its sense of smell and marks its territory with scent glands. The males perform a unique scent marking behavior called spur marking and will participate in stink fights by impregnating their tail with their scent and wafting it at opponents.

As one of the most vocal primates, the Ring-tailed Lemur utilizes numerous vocalizations including group cohesion and alarm calls. Despite the lack of a large brain (relative to simiiform primates) experiments have shown that the Ring-tailed Lemur can organize sequences, understand basic arithmetic operations and preferentially select tools based on functional qualities.

Despite being listed as Near Threatened by the IUCN Red List and suffering from habitat destruction, the Ring-tailed Lemur reproduces readily in captivity and is the most populous lemur in zoos worldwide, numbering more than 2000 individuals. It typically lives 16 to 19 years in the wild and 27 years in captivity.

RNA interference
RNA interference (RNAi) is a system within living cells that helps to control which genes are active and how active they are. Two types of small RNA molecules – microRNA (miRNA) and small interfering RNA (siRNA) – are central to RNA interference. RNAs are the direct products of genes, and these small RNAs can bind to specific other RNAs and either increase or decrease their activity, for example by preventing a messenger RNA from producing a protein. RNA interference has an important role in defending cells against parasitic genes – viruses and transposons – but also in directing development as well as gene expression in general.

The RNAi pathway is found in many eukaryotes including animals and is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short fragments of ~20 nucleotides. One of the two strands of each fragment, known as the guide strand, is then incorporated into the RNA-induced silencing complex (RISC). The most well-studied outcome is post-transcriptional gene silencing, which occurs when the guide strand base pairs with a complementary sequence of a messenger RNA molecule and induces cleavage by Argonaute, the catalytic component of the RISC complex. This process is known to spread systemically throughout the organism despite initially limited molar concentrations of siRNA.

The selective and robust effect of RNAi on gene expression makes it a valuable research tool, both in cell culture and in living organisms because synthetic dsRNA introduced into cells can induce suppression of specific genes of interest. RNAi may also be used for large-scale screens that systematically shut down each gene in the cell, which can help identify the components necessary for a particular cellular process or an event such as cell division. Exploitation of the pathway is also a promising tool in biotechnology and medicine.

Historically, RNA interference was known by other names, including post transcriptional gene silencing, and quelling. Only after these apparently unrelated processes were fully understood did it become clear that they all described the RNAi phenomenon. In 2006, Andrew Fire and Craig C. Mello shared the Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm C. elegans, which they published in 1998.

Rock Martin
The Rock Martin (Ptyonoprogne fuligula) is a small passerine bird in the swallow family that is resident in Africa, and in southwestern Asia east to Pakistan. It breeds mainly in the mountains, but also at lower altitudes, especially in rocky areas and around towns, and, unlike most swallows, it is often found far from water. It is 12–15 cm (4.7–5.9 in) long, with mainly brown plumage, paler-toned on the upper breast and underwing coverts, and with white "windows" on the spread tail in flight. The sexes are similar in appearance, but juveniles have pale fringes to the upperparts and flight feathers. The northern subspecies are smaller, paler, and whiter-throated than southern African forms, and are sometimes split as a separate species, the "Pale Crag Martin". The Rock Martin hunts along cliff faces for flying insects using a slow flight with much gliding. Its call is a soft twitter.

This martin builds a deep bowl nest on a sheltered horizontal surface, or a neat quarter-sphere against a vertical rock face or wall. The nest is constructed with mud pellets and lined with grass or feathers, and may be built on natural sites under cliff overhangs or on man-made structures such as buildings, dam walls, culverts and bridges. It is often reused for subsequent broods or in later years. This species is a solitary breeder, and is not gregarious, but small groups may breed close together in suitable locations. The two or three eggs of a typical clutch are white with brown and grey blotches, and are incubated by both adults for 16–19 days prior to hatching. Both parents then feed the chicks. Fledging takes another 22–24 days, but the young birds will return to the nest to roost for a few days after the first flight.

This small martin is caught in flight by several fast, agile falcon species, such as hobbies, and it sometimes carries parasites, but it faces no major threats. Because of its range of nearly 10 million km2 (4 million sq mi) and large, apparently stable, population, it is not seen as vulnerable and is assessed as Least Concern on the IUCN Red List.

Ruff
The Ruff (Philomachus pugnax) is a medium-sized wading bird that breeds in marshes and wet meadows across northern Eurasia. This highly gregarious sandpiper is migratory and sometimes forms huge flocks in its winter grounds, which include southern and western Europe, Africa, southern Asia and Australia. It is usually considered to be the only member of its genus, and the Broad-billed and Sharp-tailed Sandpipers are its closest relatives.

The Ruff is a long-necked, pot-bellied bird. This species shows marked sexual dimorphism; the male is much larger than the female (the reeve), and has a breeding plumage that includes brightly coloured head tufts, bare orange facial skin, extensive black on the breast, and the large collar of ornamental feathers that inspired this bird's English name. The female and the non-breeding male have grey-brown upperparts and mainly white underparts. Three differently plumaged types of male, including a rare form that mimics the female, use a variety of strategies to obtain mating opportunities at a lek, and the colourful head and neck feathers are erected as part of the elaborate main courting display. The female has one brood per year and lays four eggs in a well-hidden ground nest, incubating the eggs and rearing the chicks, which are mobile soon after hatching, on her own. Predators of wader chicks and eggs include mammals such as foxes, feral cats and stoats, and birds such as large gulls, corvids and skuas.

The Ruff forages in wet grassland and soft mud, probing or searching by sight for edible items. It primarily feeds on insects, especially in the breeding season, but it will consume plant material, including rice and maize, on migration and in winter. Classified as "least concern" on the IUCN Red List criteria, the global conservation concerns are relatively low because of the large numbers that breed in Scandinavia and the Arctic. However, the range in much of Europe is contracting because of land drainage, increased fertiliser use, the loss of mown or grazed breeding sites, and over-hunting. This decline has seen it listed in the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).

Ruffed lemurs
The ruffed lemurs of the genus Varecia are strepsirrhine primates and the largest extant lemurs within the family Lemuridae. Like all living lemurs, they are found only on the island of Madagascar. Formerly considered to be a monotypic genus, two species are now recognized: the Black-and-white Ruffed Lemur, with its three subspecies, and the Red Ruffed Lemur.

Ruffed lemurs are diurnal and arboreal quadrupeds, often observed leaping through the upper canopy of the seasonal tropical rainforests in eastern Madagascar. They are also the most frugivorous of the Malagasy lemurs, and they are very sensitive to habitat disturbance. Ruffed lemurs live in multi-male/multi-female groups and have a complex and flexible social structure, described as fission-fusion. They are highly vocal, and have loud, raucous calls.

Ruffed lemurs are seasonal breeders and highly unusual in their reproductive strategy. They are considered an "evolutionary enigma" in that they are the largest of the extant species in Lemuridae, yet exhibit reproductive traits more common in small, nocturnal lemurs, such as short gestation periods (~102 days) and relatively large average litter sizes (~2–3). Ruffed lemurs also build nests for their newborns (the only primates that do so), carry them by mouth, and exhibit an absentee parental system by stashing them while they forage. Infants are altricial, although they develop relatively quickly, traveling independently in the wild after 70 days and attaining full adult size by six months.

Threatened by habitat loss and hunting, ruffed lemurs are facing extinction in the wild. However, they reproduce readily in captivity, and have been gradually re-introduced into the wild since 1997. Organizations that are involved in ruffed lemur conservation include the Durrell Wildlife Conservation Trust, the Lemur Conservation Foundation (LCF), the Madagascar Fauna Group (MFG), Monkeyland Primate Sanctuary in South Africa, Wildlife Trust, and the Duke Lemur Center (DLC).

Rufous-crowned Sparrow
The Rufous-crowned Sparrow, Aimophila ruficeps, is a smallish American sparrow. This passerine is primarily found across the Southwestern United States and much of the interior of Mexico, south to the transverse mountain range, and to the Pacific coast to the southwest of the transverse range. It distribution is patchy, with populations often being isolated from each other. Twelve subspecies are generally recognized, though up to eighteen have been suggested. This bird has a brown back with darker streaks and gray underparts. The crown is rufous, and the face and supercilium are gray with a brown or rufous streak extending from each eye and a thick black malar streak.

These sparrows feed primarily on seeds in the winter and insects in the spring and summer. The birds are often territorial, with males guarding their territory through song and displays. Flight is awkward for this species, which prefers to hop along the ground for locomotion. They are monogamous and breed during spring. Two to five eggs are laid in the bird's nest, which is cup-shaped and well hidden. Adult sparrows are preyed upon by house cats and small raptors, while young may be taken by a range of mammals and reptiles. They have been known to live for up to three years, two months. Although the species has been classified as Least Concern, or unthreatened with extinction, some subspecies are threatened by habitat destruction and one may be extinct.

Russet Sparrow
The Russet Sparrow (Passer rutilans), also called the Cinnamon or Cinnamon Tree Sparrow, is a passerine bird of the sparrow family Passeridae. A chunky little seed-eating bird with a thick bill, it has a body length of 14 to(-). Its plumage is mainly warm rufous above and grey below. It exhibits sexual dimorphism, with both sexes having a pattern similar to that of the corresponding sex of House Sparrow. Its vocalisations are sweet and musical chirps, which when strung together form a song.

Three subspecies are recognised, differing chiefly in the yellowness of their underparts. The subspecies rutilans and intensior breed in parts of eastern Asia, where they are usually found in light woodland, and the subspecies cinnamomeus breeds in the Himalayas, where it is usually associated with terrace cultivation. The Russet Sparrow is the typical sparrow of human habitations in towns where the House and Eurasian Tree sparrows are absent. The Russet Sparrow prefers higher altitudes in the southern part of its range, but in the north it breeds by the sea. The Russet Sparrow is known well enough in the Himalayas to have a distinct name in some languages, and is depicted in Japanese art.

This sparrow feeds mainly on the seeds of herbs and grains, but it also eats berries and insects, particularly during the breeding season. This diet makes it a minor pest in agricultural areas, but also a predator of insect pests. While breeding, it is not social, as its nests are dispersed. It forms flocks when not breeding, although it does not associate with other bird species. In some parts of its range, the Russet Sparrow migrates, at least to lower altitudes. Its nest is located in a tree cavity, or a hole in a cliff or building. The male chooses the nest site before finding a mate and uses the nest for courtship display. The typical clutch contains five or six whitish eggs. Both sexes incubate and feed the young.

Sarcoscypha coccinea
Sarcoscypha coccinea, commonly known as the scarlet elf cup, or the scarlet cup, is a species of fungus in the Sarcoscyphaceae family of the Pezizales order. The fungus, widely distributed in the northern hemisphere, has been found in Africa, Asia, Europe, North and South America, and Australia. The type species of the genus Sarcoscypha, it has been known by many names since its first appearance in the scientific literature in 1772. Phylogenetic analysis shows the species to be most closely related to other Sarcoscypha species that contain numerous small oil droplets in their spores, such as the North Atlantic island species S. macaronesica. Due to similar physical appearances and sometimes overlapping distributions, S. coccinea has often been confused with S. occidentalis, S. austriaca, and S. dudleyi.

The saprobic fungus grows on decaying sticks and branches in damp spots on forest floors, generally buried under leaf litter or in the soil. The cup-shaped fruit bodies are usually produced during the cooler months of winter and early spring. The brilliant red interior of the cups—from which both the common and scientific names are derived—contrasts with the lighter-colored exterior. The edibility of the fruit bodies is not clearly established, but its small size, tough texture and insubstantial fruitings would dissuade most people from collecting for the table. The fungus has been used medicinally by the Oneida Indians, and also as a colorful component of table decorations in England. The species Molliardiomyces eucoccinea is an imperfect form of the fungus that lacks a sexually reproductive stage in its life cycle.

Sea otter
The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg (30 to 100 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter lives mostly in the ocean.

The sea otter inhabits nearshore environments where it dives to the sea floor to forage. It preys mostly upon marine invertebrates such as sea urchins, various molluscs and crustaceans, and some species of fish. Its foraging and eating habits are noteworthy in several respects. First, its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. In most of its range, it is a keystone species, controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems. Its diet includes prey species that are also valued by humans as food, leading to conflicts between sea otters and fisheries.

Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals in a fraction of their historic range. A subsequent international ban on hunting, conservation efforts, and reintroduction programs into previously populated areas have contributed to numbers rebounding, and the species now occupies about two-thirds of its former range. The recovery of the sea otter is considered an important success in marine conservation, although populations in the Aleutian Islands and California have recently declined or have plateaued at depressed levels. For these reasons (as well as its particular vulnerability to oil spills) the sea otter remains classified as an endangered species.

Seabirds
Seabirds (also known as marine birds) are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene.

In general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely.

Seabirds and humans have a long history together: they have provided food to hunters, guided fishermen to fishing stocks and led sailors to land. Many species are currently threatened by human activities, and conservation efforts are under way.

Sei Whale
The Sei Whale ( or ), Balaenoptera borealis, is a baleen whale, the third-largest rorqual after the Blue Whale and the Fin Whale. It inhabits most oceans and adjoining seas, and prefers deep off-shore waters. It avoids polar and tropical waters and semi-enclosed bodies of water. The Sei Whale migrates annually from cool and subpolar waters in summer to winter in temperate and subtropical waters.

Reaching 20 m long and weighing as much as 45 t, the Sei Whale daily consumes an average of 900 kg of food, primarily copepods,  krill, and other zooplankton. It is among the fastest of all cetaceans, and can reach speeds of up to 50 km/h, 27 knots) over short distances. The whale's name comes from the Norwegian word for pollock, a fish that appears off the coast of Norway at the same time of the year as the Sei Whale.

Following large-scale commercial whaling during the late-nineteenth and late-twentieth centuries when over 238,000 whales were taken, the Sei Whale is now internationally protected, although limited hunting occurs under controversial research programmes conducted by Iceland and Japan. As of 2006, its worldwide population was about 54,000, about a fifth of its pre-whaling population.

Seorsumuscardinus
Seorsumuscardinus is a genus of fossil dormice from the early Miocene of Europe. It is known from zone MN 4 (see MN zonation) in Oberdorf, Austria; Karydia, Greece; and Tägernaustrasse, Switzerland, and from zone MN 5 in a single site at Affalterbach, Germany. The MN 4 records are placed in the species S. alpinus and the sole MN 5 record is classified as the species S. bolligeri. The latter was placed in a separate genus, Heissigia, when it was first described in 2007, but it was reclassified as a second species of Seorsumuscardinus in 2009.

The two species of Seorsumuscardinus are known from a number of isolated teeth, which show that they were medium-sized dormice with flat teeth. The teeth are all characterized by long transverse crests coupled with shorter ones. One of these crests, the anterotropid, distinguishes the two species, as it is present in the lower molars of S. alpinus, but not in those of S. bolligeri. Another crest, the centroloph, reaches the outer margin of the first upper molar in S. bolligeri, but not in S. alpinus. Seorsumuscardinus may be related to Muscardinus, the genus of the living hazel dormouse, which appears at about the same time, and the older Glirudinus.

Short-beaked Echidna
The Short-beaked Echidna (Tachyglossus aculeatus), also known as the Spiny Anteater because of its diet of ants and termites, is one of four living species of echidna and the only member of the genus Tachyglossus. The Short-beaked Echidna is covered in fur and spines and has a distinctive snout and a specialized tongue, which it uses to catch its prey at a great speed. Like the other extant monotremes, the Short-beaked Echidna lays eggs; the monotremes are the only group of mammals to do so.

The species is found throughout Australia, where it is the most widespread native mammal, and in coastal and highland regions of southwestern New Guinea, where it is known as the Mungwe in the Daribi and Chimbu languages. It is not threatened with extinction, but human activities, such as hunting, habitat destruction, and the introduction of foreign predatory species and parasites, have reduced the distribution of the Short-beaked Echidna in Australia.

Shrimp farm
A shrimp farm is an aquaculture business that cultivates marine shrimp or prawns for human consumption. Commercial shrimp farming began in the 1970s, and production grew steeply, particularly to service the U.S., Japan and Western Europe. Global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of nearly 9 billion U.S. dollars. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% comes mainly from Latin America, where Brazil is the largest producer. Thailand is the largest exporting nation.

Shrimp farming has grown from a traditional, small-scale businesses in Southeast Asia into a global industry. Technological advances have led to growing shrimp at ever higher densities. Broodstock is shipped worldwide. Virtually all farmed shrimp are penaeids (i.e., of the family Penaeidae), and just two species of shrimp—the Penaeus vannamei (Pacific white shrimp) and the Penaeus monodon (giant tiger prawn)—account for roughly 80% of all farmed shrimp. These industrial monocultures are very susceptible to diseases, which have caused several regional wipe-outs of farm shrimp populations. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism from both NGOs and consumer countries led to changes in the industry in the late 1990s and generally stronger regulation by governments. In 1999, a program aimed at developing and promoting more sustainable farming practices was initiated, including governmental bodies, industry representatives, and environmental organizations.

Silky shark
The silky shark (Carcharhinus falciformis) is a species of requiem shark, family Carcharhinidae, named for the smooth texture of its skin. It is one of the most abundant sharks in the pelagic zone, and can be found around the world in tropical waters. Highly mobile and migratory, this shark is most often found over the edge of the continental shelf down to a depth of 50 m. The silky shark has a slender, streamlined body and typically grows to a length of 2.5 m. It can be distinguished from other large requiem sharks by its relatively small first dorsal fin with a curving rear margin, its tiny second dorsal fin with a long free rear tip, and its long, sickle-shaped pectoral fins. It is a deep, metallic bronze-gray above and white below.

With prey often scarce in its oceanic environment, the silky shark is a swift, inquisitive, and persistent hunter. It feeds mainly on bony fishes and cephalopods, and has been known to drive them into compacted schools before launching open-mouthed, slashing attacks. This species often trails schools of tuna, a favored prey. Its sense of hearing is extremely acute, allowing it to localize the low-frequency noises generated by other feeding animals, and, by extension, sources of food. The silky shark is viviparous, meaning that the developing embryos are sustained by a placental connection to their mother. There is significant geographical variation in its life history details. Reproduction occurs year-round except in the Gulf of Mexico, where it follows a seasonal cycle. Females give birth to litters of up to 16 pups annually or biennially. The newborn sharks spend their first months in relatively sheltered reef nurseries on the outer continental shelf, growing substantially before moving into the open ocean.

The large size and cutting teeth of the silky shark make it potentially dangerous, and it has behaved aggressively towards divers. However, attacks are rare as few humans enter its oceanic habitat. Silky sharks are valued for their fins, and to a lesser extent their meat, hide, liver oil, and jaws. Because of their abundance, they form a major component of commercial and artisanal shark fisheries in many countries. Furthermore, their association with tuna results in many sharks being taken as bycatch in tuna fisheries. Although slow-reproducing like most other sharks, the wide distribution and large population size of the silky shark was once thought to buffer the species against these fishing pressures. However, data now suggest that silky shark numbers are declining around the world, which prompted the International Union for Conservation of Nature (IUCN) to reassess its conservation status from Least Concern to Near Threatened in 2007.

Silky Sifaka
The Silky Sifaka (Propithecus candidus) is a large lemur characterized by long, silky white fur. It has a very restricted range in northeastern Madagascar, where it is known locally as the simpona. It is one of the rarest mammals on earth, and is listed by the International Union for Conservation of Nature (IUCN) as one of the world's 25 most critically endangered primates. The Silky Sifaka is one of nine sifaka species (genus Propithecus), and one of four former subspecies of Diademed Sifaka (P. diadema). Studies in 2004 and 2007 compared external proportions, genetics, and cranio-dental anatomy supporting full species status, which has generally been accepted.

The Silky Sifaka has a variable social structure, and lives in groups of two to nine individuals. It spends most of its day feeding and resting, though it also devotes a considerable amount of time to social behaviors, such as playing and grooming, as well as traveling. Females occasionally take priority over males during feeding. Like other eastern sifakas, it consumes mainly leaves and seeds, but also fruit, flowers, and even soil on occasion. It is a seasonal breeder and only mates one day a year during the start of the rainy season. As with other sifaka species, non-maternal infant care is common. Group members of all ages and both sexes will often groom, play, occasionally carry, and even nurse infants that are not their own. The Silky Sifaka vocalizes frequently despite its moderately sized vocal repertoire consisting of seven adult calls. Like all lemurs, it relies strongly on scent for communication. Males will frequently scent-mark on top of scent-marks made by other group members, particularly females. Males also gouge trees with their toothcomb (a special arrangement of the bottom, front teeth) prior to chest scent-marking. This chest marking results in males having brown-stained chests, the only visible trait that can be used to distinguish between adult males and adult females.

The species is only found within a few protected areas in the rainforests of northeastern Madagascar, with the majority of the remaining population in Marojejy National Park and Anjanaharibe-Sud Special Reserve. A few groups have also been found in the Makira Forest Protected Area, the Betaolana Corridor, and some unprotected forest fragments. The Silky Sifaka is hunted throughout its range as there is no local taboo (fady) against eating this species. Habitat disturbance, such as slash-and-burn agriculture (tavy), illegal logging of precious woods (particularly, rosewood) and fuel-wood, also occurs within the protected areas where it is found.

Song Thrush
The Song Thrush (Turdus philomelos) is a thrush that breeds across much of Eurasia. It is also known in English dialects as throstle or mavis. It has brown upperparts and black-spotted cream or buff underparts and has three recognised subspecies. Its distinctive song, which has repeated musical phrases, has frequently been referred to in poetry.

The Song Thrush breeds in forests, gardens and parks, and is partially migratory with many birds wintering in southern Europe, North Africa and the Middle East; it has also been introduced into New Zealand and Australia. Although it is not threatened globally, there have been serious population declines in parts of Europe, possibly due to changes in farming practices.

The Song Thrush builds a neat mud-lined cup nest in a bush or tree and lays four or five dark-spotted blue eggs. It is omnivorous and has the habit of using a favourite stone as an "anvil" on which to smash snails. Like other perching birds (passerines), it is affected by external and internal parasites and is vulnerable to predation by cats and birds of prey.

Splendid Fairywren
The Splendid Fairywren (Malurus splendens), also known simply as the Splendid Wren or more colloquially in Western Australia as the Blue Wren, is a passerine bird of the Maluridae family. It is found across much of the Australian continent from central-western New South Wales and southwestern Queensland over to coastal Western Australia. It inhabits predominantly arid and semi-arid regions. Exhibiting a high degree of sexual dimorphism, the male in breeding plumage is a small, long-tailed bird of predominantly bright blue and black colouration. Non-breeding males, females and juveniles are predominantly grey-brown in colour; this gave the early impression that males were polygamous as all dull-coloured birds were taken for females. It comprises several similar all-blue and black subspecies that were originally considered separate species.

Like other fairywrens, the Splendid Fairywren is notable for several peculiar behavioural characteristics; birds are socially monogamous and sexually promiscuous, meaning that although they form pairs between one male and one female, each partner will mate with other individuals and even assist in raising the young from such trysts. Male wrens pluck pink or purple petals and display them to females as part of a courtship display.

The habitat of the Splendid Fairywren ranges from forest to dry scrub, generally with ample vegetation for shelter. Unlike the eastern Superb Fairywren, it has not adapted well to human occupation of the landscape and has disappeared from some urbanised areas. The Splendid Fairywren mainly eats insects and supplements its diet with seeds.

Stegosaurus
Stegosaurus is a genus of stegosaurid armored dinosaur from the Late Jurassic period (late Kimmeridgian to Early Tithonian) in what is now western North America. In 2006, a specimen of Stegosaurus was announced from Portugal, showing that they were present in Europe as well. Due to its distinctive tail spikes and plates, Stegosaurus is one of the most recognizable dinosaurs, along with Tyrannosaurus, Triceratops, and Apatosaurus. The name Stegosaurus means "roof lizard" (sometimes put as "covered lizard", but in the sense that a roof covers a building) and is derived from the Greek στέγος-, stegos- ("roof") and σαῦρος, -sauros ("lizard"). At least three species have been identified in the upper Morrison Formation and are known from the remains of about 80 individuals. They lived some 150 to 145 million years ago, in an environment and time dominated by the giant sauropods Diplodocus, Camarasaurus, and Apatosaurus.

A large, heavily built, herbivorous quadruped, Stegosaurus had a distinctive and unusual posture, with a heavily rounded back, short forelimbs, head held low to the ground and a stiffened tail held high in the air. Its array of plates and spikes has been the subject of much speculation. The spikes were most likely used for defense, while the plates have also been proposed as a defensive mechanism, as well as having display and thermoregulatory (heat control) functions. Stegosaurus was the largest of all the stegosaurians (bigger than genera such as Kentrosaurus and Huayangosaurus) and, although roughly bus-sized, it nonetheless shared many anatomical features (including the tail spines and plates) with the other stegosaurian genera.

Styracosaurus
Styracosaurus (, meaning "spiked lizard" from the Ancient Greek styrax/στύραξ "spike at the butt-end of a spear-shaft" and sauros/σαῦρος "lizard") was a genus of herbivorous ceratopsian dinosaur from the Cretaceous Period (Campanian stage), about 76.5 to 75.0 million years ago. It had four to six long horns extending from its neck frill, a smaller horn on each of its cheeks, and a single horn protruding from its nose, which may have been up to 60 centimeters (2 ft) long and 15 centimeters (6 in) wide. The function or functions of the horns and frills have been debated for many years.

Styracosaurus was a relatively large dinosaur, reaching lengths of 5.5 meters (18 ft) and weighing nearly 3 tons. It stood about 1.8 meters (6 ft) tall. Styracosaurus possessed four short legs and a bulky body. Its tail was rather short. The skull had a beak and shearing cheek teeth arranged in continuous dental batteries, suggesting that the animal sliced up plants. Like other ceratopsians, this dinosaur may have been a herd animal, traveling in large groups, as suggested by bonebeds.

Named by Lawrence Lambe in 1913, Styracosaurus is a member of the Centrosaurinae. One species, S. albertensis, is currently assigned to Styracosaurus. Other species assigned to the genus have since been reassigned elsewhere.

Subfossil lemurs
Subfossil lemurs are lemurs from Madagascar that are represented by recent (subfossil) remains dating from nearly 26,000 years ago (during the late Pleistocene) to approximately 560 years ago. They include both living and extinct species, although the term more frequently refers to the extinct giant lemurs. The diversity of subfossil lemur communities was greater than that of present-day lemur communities, ranging from as high as 20 or more species per location, compared with 10 to 12 species today. Extinct species are estimated to have ranged in size from slightly over 10 kg to roughly 200 kg. Even the subfossil remains of living species are larger and more robust than the skeletal remains of modern specimens. The subfossil sites found around most of the island demonstrate that most giant lemurs had wide distributions and that ranges of living species have contracted significantly since the arrival of humans.

Despite their size, the giant lemurs shared many features with living lemurs, including rapid development, poor day vision, relatively small brains, and lack of male dominance. They also had many distinct traits among lemurs, including a tendency to rely on terrestrial locomotion, slow climbing, and suspension instead of leaping, as well as a greater dependence on leaf-eating and seed predation. The giant lemurs likely filled ecological niches now left vacant, particularly seed dispersal for plants with large seeds. There were three distinct families of giant lemur, including the Palaeopropithecidae (sloth lemurs), Megaladapidae (koala lemurs), and Archaeolemuridae (monkey lemurs). Two other types were more closely related and similar in appearance to living lemurs: the Giant Aye-aye and Pachylemur, a genus of "giant ruffed lemurs".

Subfossil remains were first discovered on Madagascar in the 1860s, but giant lemur species were not formally described until the 1890s. The paleontological interest sparked by the initial discoveries resulted in an overabundance of new species names, the allocation of bones to the wrong species, and inaccurate reconstructions during the early 1900s. Discoveries waned during the mid-1900s, although paleontological work resumed in the 1980s and resulted in the discovery of new species and a new genus. Research has recently focused on diets, lifestyle, social behavior, and other aspects of biology. The remains of the subfossil lemurs are relatively recent, with all or most species dating within the last 2,000 years. Humans first arrived on Madagascar around that time and likely played a role in the demise of the lemurs and the other megafauna that once existed on the large island. Although hunting and habitat change have been investigated as the primary cause of their extinction, a mosaic of complex interactions between multiple factors is now seen as the ultimate cause of their disappearance. Yet oral traditions and recent sightings by Malagasy villagers are still reported, suggesting either lingering populations or very recent extinctions.

Suffolk Punch
The Suffolk Punch, also historically known as the Suffolk Horse or Suffolk Sorrel, is an English breed of draught horse. The breed takes the first part of its name from the county of Suffolk in East Anglia, and the name "Punch" from its solid appearance and strength. It is a heavy draught horse which is always chestnut in colour, although the colour is traditionally spelled "chesnut" by the breed registries. Suffolk Punches are known as good doers, and tend to have energetic gaits.

The breed was developed in the early 16th century, and remains similar in phenotype to its founding stock. The Suffolk Punch was developed for farm work, and gained popularity during the early 20th century. However, as agriculture became increasingly mechanised, the breed fell out of favour, particularly from the middle part of the century, and almost disappeared completely. Although the breed's status is listed as critical by the UK Rare Breeds Survival Trust and the American Livestock Breeds Conservancy, there has been a resurgence in interest, and population numbers are increasing. As well as being used for farm work, the breed pulled artillery and non-motorised commercial vans and buses. It was also exported to other countries to upgrade local equine stock.

Sumatran Rhinoceros
The Sumatran Rhinoceros (Dicerorhinus sumatrensis) is a member of the family Rhinocerotidae and one of five extant rhinoceroses. It is the only extant species of the genus Dicerorhinus. It is the smallest rhinoceros, standing about 120–145 centimetres (3.9–4.8 ft) high at the shoulder, with a body length of 250 cm and weight of 500–800 kilograms (1100–1760 lb). Like the African species, it has two horns; the larger is the nasal horn, typically 15–25 centimetres (6–10 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran Rhino's body.

Members of the species once inhabited rainforests, swamps and cloud forests in India, Bhutan, Bangladesh, Myanmar, Laos, Thailand, Malaysia, Indonesia, and China. In historical times they lived in the southwest, particularly in Sichuan. They are now critically endangered, with only six substantial populations in the wild: four on Sumatra, one on Borneo, and one on peninsular Malaysia. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number less than 275. The decline in the number of Sumatran Rhinoceros is attributed primarily to poaching for their horns, which are highly valued in traditional Chinese medicine, fetching as much as US$30,000 per kilogram on the black market. The rhinos have also suffered from habitat loss as their forests have been cleared for lumber and conversion to agriculture.

The Sumatran Rhino is a mostly solitary animal except for courtship and child-rearing. It is the most vocal rhino species and also communicates through marking soil with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan Rhinoceros, in part because of a program that brought 40 Sumatran Rhinos into captivity with the goal of preserving the species. The program was considered a disaster even by its initiators, with most of the rhinos dying and no offspring being produced for nearly 20 years, an even worse decline than in the wild.

Superb Fairywren
The Superb Fairywren (Malurus cyaneus), also known as the Superb Blue-wren or colloquially as the Blue Wren, is a passerine bird of the Maluridae family, common and familiar across south-eastern Australia. The species is sedentary and territorial, also exhibiting a high degree of sexual dimorphism; the male in breeding plumage has a striking bright blue forehead, ear coverts, mantle, and tail, with a black mask and black or dark blue throat. Non-breeding males, females and juveniles are predominantly grey-brown in colour; this gave the early impression that males were polygamous as all dull-coloured birds were taken for females. Two subspecies are recognized: the larger and darker Tasmanian form cyaneus and the smaller and paler mainland form cyanochlamys.

Like other fairywrens, the Superb Fairywren is notable for several peculiar behavioural characteristics; the birds are socially monogamous and sexually promiscuous, meaning that although they form pairs between one male and one female, each partner will mate with other individuals and even assist in raising the young from such pairings. Male wrens pluck yellow petals and display them to females as part of a courtship display.

The Superb Fairywren can be found in almost any area that has at least a little dense undergrowth for shelter, including grasslands with scattered shrubs, moderately thick forest, woodland, heaths, and domestic gardens. It has adapted well to the urban environment and is common in suburban Sydney, Canberra and Melbourne. The Superb Fairywren mainly eats insects and supplements its diet with seeds.

Tarbosaurus
Tarbosaurus (meaning "terrifying lizard") is a genus of tyrannosaurid theropod dinosaur that flourished in Asia between 70 and 65 million years ago, at the end of the Late Cretaceous Period. Fossils have been recovered in Mongolia, with more fragmentary remains found further afield in parts of China. Although many species have been named, modern paleontologists recognize only one, T. bataar, as valid. Some experts contend that this species is actually an Asian representative of the North American genus Tyrannosaurus; if true, this would invalidate the genus Tarbosaurus altogether.

Tarbosaurus and Tyrannosaurus are considered closely related genera, even if they are not synonymous. Alioramus, also from Mongolia, is thought by some authorities to be the closest relative of Tarbosaurus. Like most known tyrannosaurids, Tarbosaurus was a large bipedal predator, weighing more than a ton and equipped with dozens of large, sharp teeth. It had a unique locking mechanism in its lower jaw and the smallest forelimbs relative to body size of all tyrannosaurids, renowned for their disproportionately tiny, two-fingered forelimbs.

Tarbosaurus lived in a humid floodplain criss-crossed by river channels. In this environment, it was an apex predator at the top of the food chain, probably preying on other large dinosaurs like the hadrosaur Saurolophus or the sauropod Nemegtosaurus. Tarbosaurus is very well-represented in the fossil record, known from dozens of specimens, including several complete skulls and skeletons. These remains have allowed scientific studies focusing on its phylogeny, skull mechanics, and brain structure.

Tasmanian devil
The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial now found in the wild only in the Australian island state of Tasmania.

The Tasmanian devil is the only extant member of the genus Sarcophilus. The size of a small dog, but stocky and muscular, the Tasmanian devil is now the largest carnivorous marsupial in the world after the extinction of the thylacine in 1936. It is characterized by its black fur, pungent odour when stressed, extremely loud and disturbing screech, and ferocity when feeding. It is known to both hunt prey and scavenge carrion and although it is usually solitary, it sometimes eats with other devils.

The Tasmanian devil was extirpated from the Australian mainland at least 3000 years ago, well before European settlement in 1788. Because they were seen as a threat to livestock in Tasmania, devils were hunted until 1941, when they became officially protected.

Since the late 1990s, devil facial tumour disease has reduced the devil population significantly and now threatens the survival of the species, which in May 2009 was declared to be endangered. Programs are currently being undertaken by the Government of Tasmania to reduce the impact of the disease.

Tawny Owl
The Tawny Owl (Strix aluco) is a stocky, medium-sized owl commonly found in woodlands across much of Eurasia. Its underparts are pale with dark streaks, and the upperparts are either brown or grey. Several of the eleven recognised subspecies have both variants. The nest is typically in a tree hole where it can protect its eggs and young against potential predators. This owl is non-migratory and highly territorial. Many young birds starve if they cannot find a vacant territory once parental care ceases.

This nocturnal bird of prey hunts mainly rodents, usually by dropping from a perch to seize its prey, which it swallows whole; in more urban areas its diet includes a higher proportion of birds. Vision and hearing adaptations and silent flight aid its night hunting. The Tawny is capable of catching smaller owls, but is itself vulnerable to the Eagle Owl or Northern Goshawk. Red Foxes are an important cause of mortality in newly fledged young.

Although many people believe this owl has exceptional night vision, its retina is no more sensitive than a human's. Rather, it is its asymmetrically placed ears that are key to its hunting because they give the Tawny Owl excellent directional hearing. Its nocturnal habits and eerie, easily imitated call, have led to a mythical association of the Tawny with bad luck and death.

Telopea speciosissima
Telopea speciosissima, commonly known as the New South Wales waratah or simply waratah, is a large shrub in the Proteaceae family. It is endemic to New South Wales in Australia and is the floral emblem of that state. No subspecies are recognised, but the closely related Telopea aspera was only recently classified as a separate species. T. speciossisima grows as a shrub to 3 or 4 m (10–13 ft) high and 2 m (7 ft) wide, with dark green leaves and several stems rising from a pronounced woody base known as a lignotuber. It is most renowned for its striking large red inflorescences (flowerheads) in spring, each made up of hundreds of individual flowers. These are visited by the eastern pygmy possum (Cercartetus nanus), birds such as honeyeaters (Meliphagidae), and insects.

The floral emblem for its home state of New South Wales, Telopea speciosissima has featured prominently in art, architecture and advertising, particularly since federation. Commercially grown in several countries as a cut flower, it is also cultivated in the home garden, although it requires good drainage, yet adequate moisture, and is vulnerable to fungal disease and pests. A number of cultivars with various shades of red, pink and even white flowers are available. Plantsmen have also developed hybrids with T. oreades and T. mongaensis, which are more tolerant of cold, shade and heavier soils.

Thescelosaurus
Thescelosaurus (, from the Greek θεσκελο-/thescelo- meaning "godlike", "marvelous", or "wondrous" and σαυρος/saurus "lizard") was a genus of small ornithopod dinosaur that appeared at the very end of the Late Cretaceous period in North America. It was a member of the last dinosaurian fauna before the Cretaceous-Tertiary extinction event around 65.5 million years ago. The preservation and completeness of many of its specimens indicate that it may have preferred to live near streams.

This bipedal ornithopod is known from several partial skeletons and skulls that indicate it grew to between 2.5 and 4.0 meters (8.2 to 13.1 ft) in length on average. It had sturdy hind limbs, small wide hands, and a head with an elongate pointed snout. This genus of dinosaur is regarded as a specialized hypsilophodont and a herbivore. Several species have been suggested for this genus. Two are currently recognized as valid, the type species T. neglectus, and T. garbanii; a third as-yet unnamed species may also be present in the known material.

The genus attracted media attention in 2000, when a specimen unearthed in 1993 in South Dakota was interpreted as including a fossilized heart. There was much discussion over whether the remains were actually of a heart. Many scientists now doubt the identification of the object and the implications of such an identification.

Thomasomys ucucha
Thomasomys ucucha, also known as the Ucucha Thomasomys, is a rodent in the genus Thomasomys of the family Cricetidae. Found only in the Cordillera Oriental of Ecuador, a mountain range, it lives in forests and grasslands at 3380 to 3720 m (11,090 to 12,200 ft) above sea level. It may occur with seven other species of Thomasomys. First collected in 1903, Thomasomys ucucha was formally described in 2003 and most closely resembles T. hylophilus, which occurs further to the north. Habitat destruction may threaten T. ucucha, so that it is listed as "Vulnerable" on the IUCN Red List.

Medium-sized, dark-furred, and long-tailed, Thomasomys ucucha can be distinguished from all other species of Thomasomys by its large, broad, procumbent upper incisors. Head and body length is 94 to 119 mm (3.7 to 4.7 in) and body mass is 24 to 46 g (0.8 to 1.6 oz). The tail is scarcely furred. The front part of the skull is flat, short, and broad. The incisive foramina, openings at the front of the palate, are short, and the palate itself is broad and smooth. The root of the lower incisor is contained in a prominent capsular process.

Thoroughbred
The Thoroughbred is a horse breed best known for its use in horse racing. Although the word thoroughbred is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed. Thoroughbreds are considered a "hot-blooded" horse, known for their agility, speed and spirit.

The Thoroughbred as it is known today was first developed in 17th and 18th century England, when native mares were crossbred with imported Arabian stallions. All modern Thoroughbreds can trace their pedigrees to three stallions originally imported into England in the 1600s and 1700s, and to 74 foundation mares of English and Oriental (Arabian, Turkoman or Barb) blood. During the 1700s and 1800s, the Thoroughbred breed spread throughout the world; they were imported into North America starting in 1730 and into Australia, Europe, Japan and South America during the 1800s. Millions of Thoroughbreds exist worldwide today, with over 118,000 foals registered each year worldwide.

Thylacine
The thylacine (, or in Australia , also  ) (binomial name: Thylacinus cynocephalus; Greek for "dog-headed pouched one") was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger (because of its striped back), the Tasmanian wolf, and colloquially the Tassie tiger or simply the tiger. Native to continental Australia, Tasmania and New Guinea, it is thought to have become extinct in the 20th century. It was the last extant member of its genus, Thylacinus, although several related species have been found in the fossil record dating back to the early Miocene.

The thylacine had become extremely rare or extinct on the Australian mainland before European settlement of the continent, but it survived on the island state of Tasmania along with several other endemic species, including the Tasmanian devil. Intensive hunting encouraged by bounties is generally blamed for its extinction, but other contributory factors may have been disease, the introduction of dogs, and human encroachment into its habitat. Despite its official classification as extinct, sightings are still reported, though none proven.

Like the tigers and wolves of the Northern Hemisphere, from which it obtained two of its common names, the thylacine was an apex predator. As a marsupial, it was not closely related to these placental mammals, but because of convergent evolution it displayed the same general form and adaptations. Its closest living relative is thought to be either the Tasmanian devil or numbat.

The thylacine was one of only two marsupials to have a pouch in both sexes (the other being the water opossum). The male thylacine had a pouch that acted as a protective sheath, protecting the male's external reproductive organs while running through thick brush. Thoroughbreds are used mainly for racing, but are also bred for other riding disciplines, such as show jumping, combined training, dressage, polo, and fox hunting. They are also commonly cross-bred with other breeds to create new breeds or to improve existing ones, and have been influential in the creation of many important breeds, such as the Quarter Horse, the Standardbred, the Anglo-Arabian, and various Warmblood breeds.

Thoroughbred racehorses perform with maximum exertion, which has resulted in high rates of accidents and other health problems. Racing has been proven to have a higher fatality rate than all other legal human and animal sports. Also, Thoroughbreds are prone to other health complications, including bleeding from the lungs, low fertility, abnormally small hearts and a small hoof to body mass ratio. There are several theories for the reasons behind the prevalence of accidents and health problems in the Thoroughbred breed, and research continues in the field.

Transandinomys
Transandinomys is a genus of rodents in the tribe Oryzomyini of family Cricetidae. It includes two species—T. bolivaris and T. talamancae—found in forests from Honduras in Central America south and east to southwestern Ecuador and northwestern Venezuela in northern South America. Until 2006, its members were included in the genus Oryzomys, but phylogenetic analysis showed that they are not closely related to the type species of that genus, and they have therefore been placed in a new genus. They may be most closely related to genera like Hylaeamys and Euryoryzomys, which contain very similar species. Both species of Transandinomys have had eventful taxonomic histories.

Transandinomys bolivaris and T. talamancae are medium-sized, soft-furred rice rats. The upperparts—brownish in T. bolivaris and reddish in T. talamancae—are much darker than the whitish underparts. Both species are characterized by very long vibrissae (whiskers), but those of T. bolivaris are particularly long. In addition to whisker length and fur color, several other morphological differences distinguish the two, including the wider first upper molar in T. bolivaris. Species of Hylaeamys and Euryoryzomys also differ from Transandinomys in some details of the skull and teeth and have shorter whiskers. Species of Transandinomys live on the ground, are active during the night, eat both plant and animal matter, and construct nests of vegetation. Both are hosts to various external parasites. They are in no apparent danger of extinction and have been assessed as "Least Concern" in the IUCN Red List.

Transandinomys bolivaris
Transandinomys bolivaris, also known as the long-whiskered rice rat, is a rodent in the genus Transandinomys. It is found in humid forest from northeastern Honduras to western Ecuador, up to 1800 m (5900 ft) above sea level. Since it was first described in 1901 from Ecuador, six scientific names have been introduced for it, but their common identity was not documented until 1998 and the species has long been known under the name Oryzomys bombycinus, described from Panama in 1912. The name Oryzomys bolivaris was used before it was moved to the new genus Transandinomys with Transandinomys talamancae (formerly Oryzomys talamancae) in 2006.

It is a medium-sized rice rat distinguished by its very long vibrissae (whiskers)—those above the eyes are up to 50 mm (2.0 in) long. The fur, which is soft and dense, is usually dark brown above and light gray below; it is darker in juveniles. The feet are long and the tail is about as long as the head and body. The skull is narrow and has a broad interorbital region (between the eyes). The species generally lives on the ground. Although it is rare, its conservation status is thought to be secure.

Transandinomys talamancae
Transandinomys talamancae is a rodent in the genus Transandinomys that occurs from Costa Rica to southwestern Ecuador and northern Venezuela. Its habitat consists of lowland forests up to 1525 m (5000 ft) above sea level. With a body mass of 38 to 74 g (1.3 to 2.6 oz), it is a medium-sized rice rat. The fur is soft and is reddish to brownish on the upperparts and white to buff on the underparts. The tail is dark brown above and lighter below and the ears and feet are long. The vibrissae (whiskers) are very long. In the skull, the rostrum (front part) is long and the braincase is low. The number of chromosomes varies from 34 to 54.

The species was first described in 1891 by Joel Asaph Allen and thereafter a variety of names, now considered synonyms, were applied to local populations. It was lumped into a widespread species "Oryzomys capito" (now Hylaeamys megacephalus) from the 1960s till the 1980s and the current allocation of synonyms dates only from 1998. It was placed in the genus Oryzomys until 2006, as Oryzomys talamancae, but is not closely related to the type species of that genus and was therefore moved to a separate genus Transandinomys in 2006. It shares this genus with Transandinomys bolivaris, which has even longer vibrissae; the two overlap broadly in distribution and are morphologically similar.

Active during the night, Transandinomys talamancae lives on the ground and eats plants and insects. Males move more and have larger home ranges than females. It breeds throughout the year, but few individuals survive for more than a year. After a gestation period of about 28 days, two to five young are born, which reach sexual maturity within two months. A variety of parasites occur on this species. Widespread and common, it is of no conservation concern.

Triaenops menamena
Triaenops menamena is a bat in the genus Triaenops found on Madagascar, mainly in the drier regions. It was known as Triaenops rufus until 2009, when it was discovered that that name had been incorrectly applied to the species. Triaenops rufus is in fact a synonym of Triaenops persicus, a Middle Eastern species closely related to T. menamena—indeed, the Malagasy species had previously been placed as a subspecies of T. persicus by some authors. Triaenops menamena is mostly found in forests, but also occurs in other habitats. It often roosts in large colonies and eats insects such as butterflies and moths. Because of its wide range, common occurrence, and tolerance of habitat degradation, it is not considered to be threatened.

With a forearm length of 50 to 56 mm (2.0 to 2.2 in) in males and 46 to 53 mm (1.8 to 2.1 in) in females, this is a medium-sized bat. Its fur color is variable, ranging from reddish-brown to gray, but it is generally darker than the species in the closely related genus Paratriaenops which also occur on Madagascar. The skull contains a pronounced swelling around the nose and the second upper premolar is displaced outside the toothrow. The maximum frequency of the echolocation call averages 94.2 kHz and the species can easily be recognized on the basis of its call.

Triceratops
Triceratops is a genus of herbivorous ceratopsid dinosaur which lived during the late Maastrichtian stage of the Late Cretaceous Period, around 68 to 65 million years ago (Mya) in what is now North America. It was one of the last dinosaur genera to appear before the great Cretaceous–Tertiary extinction event.

Bearing a large bony frill and three horns on its large four-legged body, and conjuring similarities with the modern rhinoceros, Triceratops is one of the most recognizable of all dinosaurs and the best known ceratopsid. It shared the landscape with and was preyed upon by the fearsome Tyrannosaurus, though it is less certain that the two did battle in the manner often depicted in traditional museum displays and popular images.

The exact placement of the Triceratops genus within the ceratopsid group has been debated by paleontologists. Two species, T. horridus and T. prorsus, are considered valid although many other species have been named. Recent research suggests that the contemporaneous Torosaurus, a ceratopsid long regarded as a separate genus, actually represents Triceratops in its mature form.

Triceratops has been documented by numerous remains collected since the genus was first described in 1889. Paleontologist John Scannella observed: "It is hard to walk out into the Hell Creek Formation and not stumble upon a triceratops weathering out of a hillside." Forty-seven complete or partial skulls were discovered in just that area during the decade 2000-2010. Specimens representing life stages from hatchling to adult have been found, though a complete skeleton representing a single individual has eluded fossil hunters.

The function of the frills and three distinctive facial horns has long inspired debate. Traditionally these have been viewed as defensive weapons against predators. More recent theories, noting the presence of blood vessels in the skull bones of ceratopsids, find it more probable that these features were primarily used in identification, courtship and dominance displays, much like the antlers and horns of modern reindeer, mountain goats, or rhinoceros beetles. The theory finds additional support if Torosaurus represents the mature form of Triceratops, as this would mean the frill also developed holes (fenestrae) as individuals reached maturity, rendering the structure more useful for display than defense.

Turkey Vulture
The Turkey Vulture, Cathartes aura, is a bird found throughout most of the Americas. It also known in some North American regions as the Turkey Buzzard (or just Buzzard), and in some areas of the Caribbean as the John Crow or Carrion Crow. One of three species in the genus Cathartes, in the family Cathartidae, the Turkey Vulture is the most widespread of the New World vultures, ranging from southern Canada to the southernmost tip of South America. It inhabits a variety of open and semi-open areas, including subtropical forests, shrublands, pastures, and deserts. A large bird, the turkey vulture, has a wingspan of 170–183 cm (67–72 in), a length of 64–81 cm (25–32 in), and weight of 0.85–2.26 kg (1.9–5 lb). It has dark brown to black plumage; a featherless, purplish-red head and neck; and a short, hooked, ivory-colored beak. Its life expectancy in the wild ranges upward of 16 years, with a captive life span of over 30 years being possible.

The Turkey Vulture is a scavenger and feeds almost exclusively on carrion. It finds its meals using its keen vision and sense of smell, flying low enough to detect the gasses produced by the beginnings of the process of decay in dead animals. In flight, it uses thermals to move through the air, flapping its wings infrequently. It roosts in large community groups. Lacking a syrinx—the vocal organ of birds—its only vocalizations are grunts or low hisses. It nests in caves, hollow trees, or thickets. Each year it generally raises two chicks, which it feeds by regurgitation. It has very few natural predators. In the United States of America, the vulture receives legal protection under the Migratory Bird Treaty Act of 1918.

Tyrannosaurus
Tyrannosaurus ( or, meaning 'tyrant lizard') from the Greek words τυράννος (tyrannos, meaning "tyrant") and σαύρος' (sauros, meaning "lizard"), is a genus of theropod dinosaur. The species Tyrannosaurus rex ('rex' meaning 'king' in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the last two million years of the Cretaceous Period, 67 to 65.5 million years ago. It was among the last non-avian dinosaurs to exist prior to the Cretaceous–Tertiary extinction event.

Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring up to 12.8 m in length, up to 4 m tall at the hips, and up to 6.8 MT in weight. By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running debates in paleontology.

More than 30 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology, including life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial, with some scientists considering Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.

Variegated Fairywren
The Variegated Fairywren (Malurus lamberti) is a fairywren that lives in diverse habitats spread across most of Australia. Four subspecies are recognised. Exhibiting a high degree of sexual dimorphism, the brightly coloured breeding male has chestnut shoulders and blue crown and ear coverts, while non-breeding males, females and juveniles have predominantly grey-brown plumage. Notably, females of the two subspecies rogersi and dulcis (previously termed Lavender-flanked Fairywren) have mainly blue-grey plumage.

Like other fairywrens, the Variegated Fairywren is a cooperative breeding species, with small groups of birds maintaining and defending small territories year-round. Groups consist of a socially monogamous pair with several helper birds who assist in raising the young. Male wrens pluck yellow petals and display them to females as part of a courtship display. These birds are primarily insectivorous and forage and live in the shelter of scrubby vegetation across 90% of continental Australia, which is a wider range than that of any other fairywren.

Velociraptor
Velociraptor (meaning 'swift seizer' ) is a genus of dromaeosaurid theropod dinosaur that existed approximately 75 to 71 million years ago during the later part of the Cretaceous Period. Two species are currently recognized, although others have been assigned in the past. The type species is V. mongoliensis; fossils of this species have been discovered in both Inner and Outer Mongolia in central Asia. A second species, V. osmolskae, was named in 2008 for skull material from Inner Mongolia.

Smaller than other dromaeosaurids like Deinonychus and Achillobator, the turkey-sized Velociraptor nevertheless shared many of the same anatomical features. It was a bipedal, feathered carnivore with a long, stiffened tail and an enlarged sickle-shaped claw on each hindfoot, which is thought to have been used to kill its prey. Velociraptor can be distinguished from other dromaeosaurids by its long and low skull, with an upturned snout.

Velociraptor (commonly shortened to 'raptor') is one of the dinosaur genera most familiar to the general public due to its prominent role in the Jurassic Park motion picture series. In the films it was shown with anatomical inaccuracies, including being much larger than it was in reality and without feathers. It is also well known to paleontologists, with over a dozen recovered fossil skeletons—the most of any dromaeosaurid. One particularly famous specimen preserves a Velociraptor locked in combat with a Protoceratops.

Verbascum thapsus
Verbascum thapsus (Great or Common Mullein) is a species of mullein native to Europe, northern Africa and Asia, and introduced in the Americas and Australia.

It is a hairy biennial plant that can grow to 2 m or more tall. Its small yellow flowers are densely grouped on a tall stem, which bolts from a large rosette of leaves. It grows in a wide variety of habitats, but prefers well-lit disturbed soils, where it can appear soon after the ground receives light, from long-lived seeds that persist in the soil seed bank. It is a common weedy plant that spreads by prolifically producing seeds, but rarely becomes aggressively invasive, since its seed require open ground to germinate. It is a very minor problem for most agricultural crops, since it is not a very competitive species, being intolerant of shade from other plants and unable to survive tilling. It also hosts many insects, some of which can be harmful to other plants. Although individuals are easy to remove by hand, populations are difficult to eliminate permanently.

It is widely used for herbal remedies with emollient and astringent properties. It is especially recommended for coughs and related problems, but also used in topical applications against a variety of skin problems. The plant was also used to make dyes and torches.

Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen directly with a light microscope. Viruses infect all types of organisms, from animals and plants to bacteria and archaea. Since the initial discovery of tobacco mosaic virus by Martinus Beijerinck in 1898, about 5,000 viruses have been described in detail, although there are millions of different types. Viruses are found in almost every ecosystem on Earth and are the most abundant type of biological entity. The study of viruses is known as virology, a sub-speciality of microbiology.

Virus particles (known as virions) consist of two or three parts: the genetic material made from either DNA or RNA, long molecules that carry genetic information; a protein coat that protects these genes; and in some cases an envelope of lipids that surrounds the protein coat when they are outside a cell. The shapes of viruses range from simple helical and icosahedral forms to more complex structures. The average virus is about one one-hundredth the size of the average bacterium.

The origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids — pieces of DNA that can move between cells — while others may have evolved from bacteria. In evolution, viruses are an important means of horizontal gene transfer, which increases genetic diversity.

Viruses spread in many ways; plant viruses are often transmitted from plant to plant by insects that feed on sap, such as aphids, while animal viruses can be carried by blood-sucking insects. These disease-bearing organisms are known as vectors. Influenza viruses are spread by coughing and sneezing. The norovirus and rotavirus, common causes of viral gastroenteritis, are transmitted by the faecal-oral route and are passed from person to person by contact, entering the body in food or water. HIV is one of several viruses transmitted through sexual contact and by exposure to infected blood. Viruses can infect only a limited range of host cells called the "host range". This can be narrow or, as when a virus is capable of infecting many species, broad.

Viral infections in animals provoke an immune response that usually eliminates the infecting virus. Immune responses can also be produced by vaccines, which confer an artificially acquired immunity to the specific viral infection. However, some viruses including those causing AIDS and viral hepatitis evade these immune responses and result in chronic infections. Antibiotics have no effect on viruses, but several antiviral drugs have been developed.

White-breasted Nuthatch
The White-breasted Nuthatch (Sitta carolinensis) is a small songbird of the nuthatch family which breeds in old-growth woodland across much of temperate North America. It is a stocky bird, with a large head, short tail, powerful bill and strong feet. The upperparts are pale blue-gray, and the face and underparts are white. It has a black cap and a chestnut lower belly. The nine subspecies differ mainly in the color of the body plumage.

Like other nuthatches, the White-breasted Nuthatch forages for insects on trunks and branches, and is able to move head-first down trees. Seeds form a substantial part of its winter diet, as do acorns and hickory nuts that were stored by the bird in the fall. The nest is in a hole in a tree, and the breeding pair may smear insects around the entrance as a deterrent to squirrels. Adults and young may be killed by hawks, owls and snakes, and forest clearance may lead to local habitat loss, but this is a common species with no major conservation concerns over most of its range.

White-winged Fairywren
The White-winged Fairywren (Malurus leucopterus) is a species of passerine bird in the fairywren family Maluridae. It lives in the drier parts of central Australia; from central Queensland and South Australia across to Western Australia. Like other fairywrens, this species displays marked sexual dimorphism and one or more males of a social group grow brightly coloured plumage during the breeding season. The female is sandy-brown with light-blue tail feathers; it is smaller than the male, which, in breeding plumage, has a bright-blue body, black bill, and white wings. Younger sexually mature males are almost indistinguishable from females and are often the breeding males. A troop of White-winged Fairywrens in spring and summer has a brightly coloured older male accompanied by small, inconspicuous brown birds, many of which are also male. Three subspecies are recognised. Apart from the mainland subspecies, one is found on Dirk Hartog Island, and another on Barrow Island off the coast of Western Australia. Males from these islands have black rather than blue breeding plumage. The White-winged Fairywren mainly eats insects, supplementing this with small fruits and leaf buds. It occurs in heathland and arid scrubland, where low shrubs provide cover. Like other fairywrens, it is a cooperative breeding species, and small groups of birds maintain and defend territories year-round. Groups consist of a socially monogamous pair with several helper birds who assist in raising the young. These helpers are progeny that have attained sexual maturity but remain with the family group for one or more years after fledging. Although not yet confirmed genetically, the White-winged Fairywren may be promiscuous and assist in raising the young from other pairings. As part of a courtship display, the male wren plucks petals from flowers and displays them to female birds.

Willie Wagtail
The Willie (or Willy) Wagtail (Rhipidura leucophrys) is a passerine bird native to Australia, New Guinea, the Solomon Islands, the Bismarck Archipelago, and eastern Indonesia. It is a common and familiar bird throughout much of its range, living in most habitats apart from thick forest. Measuring 19.0–21.5 cm (7½–8½ in) in length, the Willie Wagtail is contrastingly coloured with almost entirely black upperparts and white underparts; the male and female have similar plumage. Three subspecies are recognised; leucophrys from central and southern Australia, the smaller picata from northern Australia, and the larger melaleuca from New Guinea and islands in its vicinity. It is unrelated to the true wagtails of the genus Motacilla; it is a member of the fantail genus Rhipidura and is a part of a 'core corvine' group that includes true crows and ravens, drongos and birds of paradise. Within this group, fantails are placed in the family Dicruridae, although some authorities consider them distinct enough to warrant their own small family, Rhipiduridae.

The Willie Wagtail is insectivorous and spends much time chasing prey in open habitat. Its common name is derived from its habit of wagging its tail horizontally when foraging on the ground. Aggressive and territorial, the Willie Wagtail will often harass much larger birds such as the Laughing Kookaburra and Wedge-tailed Eagle. It has responded well to human alteration of the landscape and is a common sight in urban lawns, parks, and gardens. It was widely featured in aboriginal folklore around the country as either a bringer of bad news or a stealer of secrets.

Yellow-tailed Black Cockatoo
The Yellow-tailed Black Cockatoo (Calyptorhynchus funereus) is a large cockatoo native to the south-east of Australia measuring 55–65 cm (22–26 in) in length. It has a short crest on the top of its head. Its plumage is mostly brownish black and it has prominent yellow cheek patches and a yellow tail band. The body feathers are edged with yellow giving a scalloped appearance. The adult male has a black beak and pinkish-red eye-rings, and the female has a bone-coloured beak and grey eye-rings. In flight, Yellow-tailed Black Cockatoos flap deeply and slowly, and with a peculiar heavy fluid motion. Their loud eerie wailing calls carry for long distances.

Yellow-tailed Black Cockatoo is found in forested regions from south and central eastern Queensland to southeastern South Australia including a very small population persisting in the Eyre Peninsula. Two subspecies are recognised, although Tasmanian and southern mainland populations of the southern subspecies xanthanotus may be distinct enough from each other to bring the total to three. Birds of subspecies funereus (Queensland to eastern Victoria) have longer wings and tails and darker plumage overall, while those of xanthanotus (western Victoria, South Australia and Tasmania) have more prominent scalloping.

Unlike other cockatoos, a large proportion of the Yellow-tailed Black Cockatoo's diet is made up of wood-boring grubs, and they also eat seeds. They nest in hollows situated high in trees with fairly large diameters, generally Eucalyptus. Although, they remain common throughout much of their range, fragmentation of habitat and loss of large trees suitable for nesting has caused a population decline in Victoria and South Australia. In some places Yellow-tailed Black Cockatoos appear to have adapted to humans and they can often be seen in parts of urban Sydney and Melbourne. It is not commonly seen in aviculture, especially outside Australia. Like most parrots, it is protected by CITES, an international agreement, that makes trade, export, and import of listed wild-caught species illegal.

Zapata Rail
The Zapata Rail, Cyanolimnas cerverai, is a 29 cm (11.4 in) long, dark-coloured rail, the only member of the monotypic genus Cyanolimnas. It has brown upperparts, greyish-blue underparts, a red-based yellow bill, white undertail coverts, and red eyes and legs. Its short wings render it almost flightless. It is endemic to the wetlands of the Zapata Peninsula in southern Cuba, where its only known nest was found in sawgrass tussocks. Little is known of its diet or reproductive behaviour, and its described calls may belong to a different species.

The Zapata Rail was discovered by Spanish zoologist Fermín Zanón Cervera in March 1927 in the Zapata Swamp near Santo Tomás, in the southern Matanzas province of Cuba. The swamp holds one other bird found nowhere else, the Zapata Wren, and also gives its name to the Zapata Sparrow. Due to ongoing habitat loss in its limited range, its small population size, and predation by introduced mammals and catfish, the Zapata Rail is evaluated as endangered on the IUCN Red List of threatened species. Tourism and climate change may pose threats in the future.