What is the difference between Saurischians and Ornithischians?

Saurischians and Ornithischians are two groups of dinosaur, defined in terms of pelvic structure. Saurischians, whose name means "lizards", had a pelvic structure more similar to the structure of modern lizards, while the Ornithischians ("bird-shaped") had the pelvic structure more like modern birds. Many scientists are confusing that modern birds have actually evolved from a group of dinosaurs from a lizard called coelurosaurs, which developed a hip bird in an example of parallel development. All Delian dinosaurs disappeared about 65 million years ago at an event called Winging and Tertiary Extinction. Saurischians did not leave any living offspring.

Saurischians mostly consisted of teropods, including all carnivorous dinosaurs, including t. Rex and Sauropodomorf, which included Sauropods, by far the largest group of dinosaurs and one of the two large lines of herbal dinosaurs. Ornithischians included a large number of herbivores, some of which traveled in herds, betweenThere are keratopians such as Triceratops , armored and club anellosaurs, duck hadrosaurs and stegosaurs, with distinctive boards and spines. Ornithischians were prey therapy and were generally smaller than titanic sauropods.

both groups were distinguished from each other in the late Triassical period, between 230 and 225 million years. One of the first and perhaps closely related to the common predecessor of all dinosaurs, the fossil type of eorator , was lizards, while the earliest known dinosaurus, pisanosaurus mertii , is dated several million years later. Both were about a length of about a meter. Around this time, a line similar to Sauropod, called prosauropods, has also developed, and quickly reached as large as 10 m (33 ft), unusually large for this time in the country in History.

Both groups of dinosaur occurred on the importance of only 20-30 million years after the extinction of the Permian-Triassic, which deleted most of the whole life and created many open niches for dinosaurs to be occupied. The evolutionary situation at that time was analogous to what happened 65 million years ago - when the dinosaurs died and left many niches open to mammals.