Dinosaurs refer to the popular concept of an extinct, usually large, vertebrate animal group. These are prehistoric inhabitants of the Earth's ecosystem and scientists estimate that these influential animals ruled the world for some 16 million years. The evolution of the first dinosaur was approximately 23 million years ago. At the end of the Cretaceous era, a devastating natural disaster almost completely destroyed the effects of dinosaurs from around the world 60 million years ago. A class of them is believed to have survived only to the present era: classmates think that modern birds are the descendants of Theropod dinosaurs. This evolutionary evidence is found in the Jurassic period from the signs obtained by fossils.
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Generally, triciropods, niernites (modern birds), their most recent common ancestors (most recent Common Ancestor / MRCA) and their descendants are called dinosaurs under the classification of ethnic groups [10]. According to another opinion, in the form of meglossasaurus and Iguanadan. Should start the process of identifying dinosaurs, because Richard Owen was diagnosed with dinosaurs, these two were one of the three people he specified . The two methods identify the same biosphere as dinosaurs: dinosauria = ornithiczia + sariskia; They include the therapeads (mainly bipad and birds), anchylosaura (cobbled four-wheeler), stogosar (cauliflower foursquare), chortzpia (horn and helmet four-wheeler), ornithopod (sagittarius, duplex or quadruped) and saropodromorph (mainly tall Quadriceps
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