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 Chitinozoan fossil. Chitinozoa (singular: chitinozoan, plural: chitinozoans) are a taxon of flask-shaped, organic walled marine microfossils produced by an as yet unknown animal. Common from the Ordovician to Devonian periods (i.e. the mid-Paleozoic), the millimetre-scale organisms are abundant in almost all types of marine sediment across the globe. This wide distribution, and their rapid pace of evolution, makes them valuable biostratigraphic markers. Their bizarre form has made classification and ecological reconstruction difficult. Since their discovery in 1931, suggestions of protist, plant, and fungalaffinities have all been entertained. The organisms have been better understood as improvements in microscopy facilitated the study of their fine structure, and there is mounting evidence to suggest that they represent either the eggs or juvenile stage of a marine animal. The ecology of chitinozoa is also open to speculation; some may have floated in the water column, where others may have attached themselves to other organisms. Most species were particular about their living conditions, and tend to be most common in specific paleoenvironments. Their abundance also varied with the seasons.(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 Polar dinosaurs could have walked to Australia, because during the early Cretaceous the continent of Australia was still linked to Antarctica? ... that highlights from the history of ankylosaur research include one of the first dinosaurs ever discovered and a dinosaur with armored eyelids? ... that the extinct Pliocene dolphin Australodelphis from the Vestfold Hills of Antarctica has been described as an example of convergent evolution with whales? ... that highlights from the history of dromaeosaurid research include a skeleton of Velociraptor preserved in combat with a Protoceratops, the gigantic Utahraptor, and tiny four-winged Microraptor? ...that ostracoderms are the earliest known vertebrate animals? Subcategories Category Prehistory of Antarctica not found 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