User:Abyssal/Prehistory of Antarctica

The Prehistory of Antarctica Portal In general... Paleogeography of the Late Cretaceous (90 Ma); the Antarctic Circle is at 60°S The South Polar region of the Cretaceous comprised the continent of East Gondwana–modern day Australia, Zealandia, and Antarctica–a product of the break-up of Gondwana in the Cretaceous Period. The southern region, during this time, was much warmer than it is today, ranging from perhaps 4–8 °C (39–46 °F) in the latest Cretaceous Maastrichtian in what is now southeastern Australia. This prevented permanent ice sheets from developing and fostered polar forests, which were largely dominated by conifers, cycads, and ferns, and relied on a temperate climate and heavy rainfall. Major fossil-bearing geological formations that record this area are: the Santa Marta and Sobral Formations of Seymour Island off the Antarctic Peninsula; the Snow Hill Island, Lopez de Bertodano, and the Hidden Lake Formations on James Ross Island also off the Antarctic Peninsula; and the Eumeralla and Wonthaggi Formations in Australia. The South Polar region housed many endemic species, including several relict forms that had gone extinct elsewhere by the Cretaceous. Of the dinosaur assemblage, the most diverse were the small hypsilophodont-like dinosaurs. The South Polar region also was home to the last labyrinthodont amphibian, Koolasuchus. The isolation of Antarctica produced a distinct ecosystem of marine life called the Weddellian Province. (Full article...) Selected article on prehistoric Antarctica Specifiers for Dinosauria. Dinosaurs are a diverse group of animals that first appeared during the Triassic period, 231.4 million years ago, and were the dominant terrestrial vertebrates for 135 million years, from the beginning of the Jurassic until the end of the Cretaceous (66 million years ago), when the Cretaceous–Paleogene extinction event led to the extinction of most dinosaur groups. The fossil record indicates that birds evolved from theropod dinosaurs and, consequently, they are considered a subgroup of dinosaurs by many paleontologists. Some birds survived the extinction event and their descendants continue the dinosaur lineage to the present day. Using fossil evidence, paleontologists have identified over 500 distinct genera of non-avian dinosaurs. Dinosaurs are represented on every continent. Some are herbivorous, others carnivorous. While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines. Evidence suggests that egg laying and nest building are additional traits shared by all dinosaurs. While modern birds are generally small due to the constraints of flight, many prehistoric dinosaurs were large-bodied—the largest sauropod dinosaurs may have achieved lengths of 58 meters (190 feet). Many dinosaurs were quite small: Xixianykus, for example, was only about 50 cm (20 in) long. (see more...) Selected article on the prehistory of Antarctica in human science, culture and economics Illustration of trilobite fossils by Joachim Barrande. The history of paleontology traces the history of the effort to study the fossil record left behind by ancient life forms. Although fossils had been studied by scholars since ancient times, the nature of fossils and their relationship to life in the past became better understood during the 17th and 18th centuries. At the end of the 18th century the work of Georges Cuvier ended a long running debate about the reality of extinction and led to the emergence of paleontology as a scientific discipline. The first half of the 19th century saw paleontological activity become increasingly well organized. This contributed to a rapid increase in knowledge about the history of life on Earth, and progress towards definition of the geologic time scale. As knowledge of life's history continued to improve, it became increasingly obvious that there had been some kind of successive order to the development of life. After Charles Darwin published Origin of Species in 1859, much of the focus of paleontology shifted to understanding evolutionary paths. The last half of the 19th century saw a tremendous expansion in paleontological activity, especially in North America. The trend continued in the 20th century with additional regions of the Earth being opened to systematic fossil collection, as demonstrated by a series of important discoveries in China near the end of the 20th century. There was also a renewed interest in the Cambrian explosion that saw the development of the body plans of most animal phyla. (see more...) Need help? Do you have a question about Abyssal/Prehistory of Antarctica that you can't find the answer to? Consider asking it at the Wikipedia reference desk. Did you know? ... that multiple Leptocleidus skeletons have been found preserved as gemstone quality opal over the course of the history of plesiosaur research? ... that modern humans have been found to inhabit various countries for periods ranging from almost 200,000 years to less than 800 years? ...that eighty years on, scientists are still debating whether the Palæozoic fossils known as Chitinozoans (SEM image pictured) represent plants, animals or eggs? ... that what is now the southwestern United States was at one time connected to East Antarctica according to the SWEAT model? ... that lice from mummified guinea pigs and mites preserved in amber while feeding on spiders have provided evidence for researchers in the field of paleoparasitology? Subcategories Prehistory of Antarctica Geology of Antarctica Paleontological sites of Antarctica Cenozoic Antarctica Extinct animals of Antarctica Prehistoric life of Antarctica Mesozoic Antarctica Paleozoic Antarctica Things you can do Things you can do In a nutshell: Further develop this portal! Start Topics section. Create In this month section. Add new articles: Eumantellidae Oudenodontidae Dinodontosauridae Marambio Group Uralocynodon Sinognathinae Eoraetia Nanictosaurus Sinognathus Austrobrachyops Nanocynodon Dromatherium Santacruzgnathus Scalenodontoides Chaliminia Pattsia Buckley Formation Hobbs Glacier Formation Moby Dick Group Cape Melville Formation Takrouna Formation LeMay Group Lully Foothills Formation Mount King Formation President Beaches Formation Dromatheriidae Bonacynodon Trirachodontinae Microscalenodon Gaumia Microconodon Pseudotriconodon Related content Prehistory of Africa Prehistory of North America Prehistory of South America Prehistory of Asia Prehistory of Europe Prehistory of Oceania Antarctica Archaeology Earth sciences Paleontology Extinct and Endangered Species Paleozoic Mesozoic Cenozoic Dinosaurs 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:Portals with titles not starting with a proper noun