User:Abyssal/Prehistory of North America
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The Prehistory of North America PortalIntroductionSelected article on prehistoric North America
Aetosaurs (order name Aetosauria) are an extinct order of heavily armoured, medium- to large-sized Late Triassic herbivorous archosaurs. They have small heads, upturned snouts, erect limbs, and a body covered by plate-like scutes. All aetosaurs belong to the family Stagonolepididae. Two distinct subdivisions of aeotosaurs are currently recognized, Desmatosuchinae and Aetosaurinae, based primarily on differences in the morphology of the bony scutes of the two groups. Over 20 genera of aetosaurs have been described.
Aetosaur fossil remains are known from Europe, North and South America, parts of Africa and India. Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils. Many aetosaurs had wide geographic ranges, but their stratigraphic ranges were relatively short. Therefore, the presence of particular aetosaurs can accurately date a site that they are found in. Aetosaur remains have been found since the early 19th century, although the very first remains that were described were mistaken for fish scales. Aetosaurs were later recognized as crocodile relatives, with early paleontologists considering them to be semiaquatic scavengers. They are now considered to have been entirely terrestrial animals. Some forms have characteristics that may have been adaptations to digging for food. There is also evidence that some if not all aetosaurs made nests. (see more...) Need help?Do you have a question about Abyssal/Prehistory of North America that you can't find the answer to? Consider asking it at the Wikipedia reference desk. Selected article on the prehistory of North America in science, culture and economicsThe Petrified Forest is known for its fossils, especially fallen trees that lived in the Late Triassic, about 225 million years ago. The sediments containing the fossil logs are part of the widespread and colorful Chinle Formation, from which the Painted Desert gets its name. Beginning about 60 million years ago, the Colorado Plateau, of which the park is part, was pushed upward by tectonic forces and exposed to increased erosion. All of the park's rock layers above the Chinle, except geologically recent ones found in parts of the park, have been removed by wind and water. In addition to petrified logs, fossils found in the park have included Late Triassic ferns, cycads, ginkgoes, and many other plants as well as fauna including giant reptiles called phytosaurs, large amphibians, and early dinosaurs. Paleontologists have been unearthing and studying the park's fossils since the early 20th century. (see more...) Did you know?
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Quality ContentFeatured prehistory of North America articles - Acrocanthosaurus - Albertosaurus - Allosaurus - Bone Sharps, Cowboys, and Thunder Lizards - Bone Wars -Chicxulub crater - Columbian mammoth - Edward Drinker Cope - Cretaceous–Paleogene extinction event - Daspletosaurus - Deinonychus - Deinosuchus - Dinosaur - Diplodocus - Ediacara biota - Edmontosaurus - Gorgosaurus - Lambeosaurus - Parasaurolophus - Petrified Forest National Park - Stegosaurus - Styracosaurus - Thescelosaurus - Triceratops - Tyrannosaurus - Woolly mammoth Good prehistory of North America articles - ?Oryzomys pliocaenicus - Aetosaur - Archaeomarasmius - Chitinozoan - Cloudinid - Coal ball - Dimetrodon - Stephen Jay Gould - History of paleontology - Kirtlandian - Macabeemyrma - Megalodon - Ornatifilum - Othnielosaurus - Protomycena - Pteranodon - Pterosaur - Saint Croix macaw - Small shelly fauna - Smilodon - Temnospondyli - Tiktaalik - Waptia SubcategoriesThings you can doDesired articles, sorted by how frequently linked to:
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