Search results
Results From The WOW.Com Content Network
A model of the hypothetical dinosauroid, Dinosaur Museum, Dorchester The dinosauroid is a hypothetical species created by Dale A. Russell in 1982. Russell theorized that if a dinosaur such as Stenonychosaurus had not perished in the Cretaceous–Paleogene extinction event, its descendants might have evolved to fill the same ecological niche as humans. [1]
Around 1880, dinosaurs were largely treated as a monophyletic group (i.e. having a last common ancestor not shared with other reptiles). However, Harry Seeley disagreed with this interpretation, and split the Dinosauria into two orders, the Saurischia ("lizard-hipped") and the Ornithischia ("bird-hipped"), which were seen as members of the Archosauria with no special relationship to each other.
Beginning of animal evolution. [54] [55] 720–630 Ma Possible global glaciation [56] [57] which increased the atmospheric oxygen and decreased carbon dioxide, and was either caused by land plant evolution [58] or resulted in it. [59] Opinion is divided on whether it increased or decreased biodiversity or the rate of evolution. [60] [61] [62 ...
Dinosaurs are a diverse group of reptiles [note 1] of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research.
The book begins with the evolution of proto-dinosaurs and dinosaurs' emergence from the Permian-Triassic extinction.The early dinosaurs were not very successful. They became the dominant animals at the beginning of the Jurassic period, which was marked by a mass extinction of many of their competitors.
Darwin did not publish his ideas on evolution for 20 years. However, he did share them with certain other naturalists and friends, starting with Joseph Dalton Hooker, with whom he discussed his unpublished 1844 essay on natural selection. During this period he used the time he could spare from his other scientific work to slowly refine his ...
Archosaurs are ancestrally superprecocial as evidenced in various dinosaurs, pterosaurs, and crocodylomorphs. [43] However, parental care did evolve independently multiple times in crocodilians, dinosaurs, and aetosaurs. [44] In most such species the animals bury their eggs and rely on temperature-dependent sex determination.
Some creationists further believe that dinosaurs survived the Biblical flood since the Bible states that "every kind of land animal" did. [12] Creationists also tend to reject the fossil evidence that many non-avian dinosaurs were feathered, since this is among the evidence that birds descended from them through evolution. [14]