By phylogenetic nomenclature, dinosaurs are often defined as a group that includes the most recent common ancestor (MRCA) of the Triceratops (triceratops) and birds, along with all their descendants. It is also suggested that Dinosauria should have the definition related to the MRCA of Megalosaurus and Iguanodon, because these are two of the three subspecies cited by Richard Owen when he recognized the Dinosauria clade. resulting in the same group of animals defined as dinosaurs: “Dinosauria = Ornithischia (bird’s hip) + Saurischia (lizard hip)”, which includes armored dinosaurs, hornbills, and horned dinosaurs (animals herbivores with horns and halves), raptor (two or four legged herbivores), dinosaurs (mainly bipedal predators and birds) and lizard-footed dinosaurs (owner are weakly large four-legged herbivores with a long neck and tail).
Birds are currently recognized as the only surviving lineage of the arthropod. In the traditional classification the bird is considered to be a distinct class that has evolved from the dinosaur, a separate inter-order. Most contemporary paleontologists studying dinosaurs, however, reject the traditional taxonomy of phylogenetic classification; This approach requires that, in order for a group to be natural, all descendants of the member species must also be included in the group. Consequently, birds are considered dinosaurs and dinosaurs, therefore, not extinct. Lizard hips, and dinosaurs.