User:Abyssal/Portal:Permian

The Permian Portal Introduction Selected article on the Permian world and its legacies Modern entoprocts. Entoprocta is a phylum of mostly sessile marine animals, ranging from 0.1 to 7 millimetres (0.0039 to 0.2756 in) long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and both the mouth and anus lie inside the "crown". Most families of entoprocts are colonial. Some species eject unfertilized ova into the water, while others keep their ova in brood chambers until they hatch, and some of these species use placenta-like organs to nourish the developing eggs. After hatching, the larvae swim for a short time and then settle on a surface. There they metamorphose, and the larval gut generally rotates by up to 180°, so that the mouth and anus face upwards. Both colonial and solitary species also reproduce by cloning – solitary species grow clones in the space between the tentacles and then release them when developed, while colonial ones produce new members from the stalks or from corridor-like stolons. Fossils of entoprocts are very rare, and the earliest specimens that have been identified with confidence date from the Late Jurassic. Most studies from 1996 onwards have regarded entoprocts as members of the Trochozoa, which also includes molluscs and annelids. However, a study in 2008 concluded that entoprocts are closely related to bryozoans. Recently, the Maotianshan Shales fossil,Cotyledion tylodes, has been reevaluated as being an ancient, sclerite-bearing entoproct. (see more...) Did you know? Skeletal mount of Scutosaurus. ... that the group Pareiasauromorpha includes parareptiles that lived from 271 to 252 million years ago?" ... that fossils of the temnospondyl amphibian Kourerpeton were notoriously discovered in the window of a barber's shop in Arizona? ... that although it was first classified as a reptile, the extinct genus Batropetes (restoration pictured) is now known to be a microsaur amphibian? ... that the largest known ovules produced by any non-flowering seed-plant came from the Medullosales (fossilized leaves pictured), an order of extinct seed ferns? ...that the extinct crocodile-like Prionosuchus is the largest amphibian known to have existed? Need help? Do you have a question about Abyssal/Portal:Permian that you can't find the answer to? Consider asking it at the Wikipedia reference desk. Selected image Clast-supported, polymictic conglomerate in the Woodton Formation (Permian), NSW, Australia. Photo credit: Rygel, M.C. Selected article on the Permian in human science, culture and economics A skeletal mount of Edaphosaurus. Paleontology or palaeontology (/ˌpeɪliɒnˈtɒlədʒi, ˌpæli-, -ən-/) is the scientific study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments (their paleoecology). As a "historical science" it attempts to explain causes rather than conduct experiments to observe effects. Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek: παλαιός (palaios) meaning "old, ancient," ὄν, ὀντ- (on, ont-), meaning "being, creature" and λόγος (logos), meaning "speech, thought, study". Paleontology lies on the border between biology and geology. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics and engineering. Use of all these techniques has enabled paleontologists to discover much of the evolutionary history of life, almost all the way back to when Earth became capable of supporting life, about 3,800 million years ago. As knowledge has increased, paleontology has developed specialized sub-divisions, some of which focus on different types of fossil organisms while others study ecology and environmental history, such as ancient climates. Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave fossils. (see more...) Geochronology Epochs - Cisuralian - Guadalupian - Lopingian Ages - Asselian - Sakmarian - Artinskian - Kungurian - Roadian - Wordian - Capitanian -Wuchiapingian - Changhsingian Events - Hunter-Bowen orogeny - Permian–Triassic extinction event Geography - Pangaea - Panthalassa Animals - Ammonoids - Blattopterans - Dicynodonts - Dinocephalians - Fusulinids - Gorgonopsians - Lepospondyls - Pareiasaurs - Pelycosaurs - Temnospondyls - Trilobites Plants - Conifers - Cycads - Ginkgos - Seed ferns Stratigraphic units - Red Beds of Texas and Oklahoma Researchers - Edward Drinker Cope Culture - Animal Armageddon - The Day The Earth Nearly Died - List of creatures in the Walking with... series - Walking with Monsters Subcategories Permian Permian Africa Permian Antarctica Permian Asia Permian Europe Permian North America Permian Oceania Permian South America Permian geochronology Permian events Permian geology Permian life Permian paleogeography Permian stubs Quality Content Featured Permian articles - Amphibian Good Permian articles - Dimetrodon - Temnospondyli Things you can do Here are some tasks awaiting attention: Stubs : Permian stubs Current Permian FACs - none currently Related content Time Earth sciences Paleontology Extinct and Endangered Species Paleozoic Cambrian Ordovician Silurian Devonian Carboniferous Permian Mesozoic Associated Wikimedia The following Wikimedia Foundation sister projects provide more on this subject: Commons Free media repository Wikibooks Free textbooks and manuals Wikidata Free knowledge base Wikinews Free-content news Wikiquote Collection of quotations Wikisource Free-content library Wikiversity Free learning tools Wiktionary Dictionary and thesaurus ¤ Category:Geologic time portals