Search results
Results from the WOW.Com Content Network
Ancestrally, dinosaurs showed approximately 50 caudal vertebrae, although their number, size, and shape varied considerably in the separate groups. The number of caudals decreased along the evolutionary line leading to modern birds; in the latter, the remaining caudals are fused together into a pygostyle.
The mode of Mesozoic dinosaur body masses is between 1 and 10 metric tons (1.1 and 11.0 short tons). [139] This contrasts sharply with the average size of Cenozoic mammals, estimated by the National Museum of Natural History as about 2 to 5 kg (4.4 to 11.0 lb). [140] The sauropods were the largest and heaviest dinosaurs.
This is a list of stratigraphic units from which dinosaur body fossils have been recovered. Although Dinosauria is a clade which includes modern birds, this article covers only Mesozoic stratigraphic units. Units listed are all either formation rank or higher (e.g. group).
The following outline is provided as an overview of and topical guide to dinosaurs: . Dinosaurs – diverse group of animals of the clade and superorder Dinosauria.They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period (about in 1963) until the end of the Cretaceous (2000), when the Cretaceous–Paleogene extinction event led to the extinction ...
Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia.It is the sister group of the Thyreophora within the clade Genasauria.Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth.
For premium support please call: 800-290-4726 more ways to reach us
Tyrannosaurus (/ t ɪ ˌ r æ n ə ˈ s ɔː r ə s, t aɪ-/) [a] is a genus of large theropod dinosaur.The type species Tyrannosaurus rex (rex meaning 'king' in Latin), often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!