User:Abyssal/Prehistory of Antarctica

The Prehistory of Antarctica Portal In general... Antarctica without its ice cover. This map does not consider that sea level would rise because of the melted ice, or that the landmass would rise by several hundred meters over a few tens of thousands of years after the weight of the ice was no longer depressing the landmass. The geology of Antarctica covers the geological development of the continent through the Archean, Proterozoic and Phanerozoic eons. The geological study of Antarctica has been greatly hindered by the fact that nearly all of the continent is continuously covered with a thick layer of ice. However, techniques such as remote sensing have begun to reveal the structures beneath the ice. Geologically, West Antarctica closely resembles the Andes of South America. The Antarctic Peninsula was formed by uplift and metamorphism of sea-bed sediments during the late Paleozoic and the early Mesozoic eras. This sediment uplift was accompanied by igneous intrusions and volcanism. The most common rocks in West Antarctica are andesite and rhyolite volcanics formed during the Jurassic Period. There is also evidence of volcanic activity, even after the ice sheet had formed, in Marie Byrd Land and Alexander Island. The only anomalous area of West Antarctica is the Ellsworth Mountains region, where the stratigraphy is more similar to the eastern part of the continent. (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 the Antarctic Peninsula has experienced subduction for over 200 million years? ... that the extinct amphibian Cryobatrachus (restoration pictured) was discovered in the Transantarctic Mountains of Antarctica? ... that during the 20th century, the first large-scale excavation of dinosaur footprints was undertaken in Texas for an exhibit at the American Museum of Natural History? ...that fossil Thelodont fish (depiction pictured) surprised scientists by showing that stomachs evolved before jaws? ... that microbial mats increase our understanding of evolution by helping to preserve soft-bodied organisms and soft parts of hard-shelled 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