Ornithischia ( /ɔrnɨˈθɪskiə/ or-ni-THISS-kee-ə) or Predentata is an extinct order of beaked, herbivorous dinosaurs. The name ornithischia is derived from the Greek ornitheos (ορνιθειος) meaning 'of a bird' and ischion (ισχιον) meaning 'hip joint'. They are known as the 'bird-hipped' dinosaurs because of their bird-like hip structure, even though birds actually descended from the 'lizard-hipped' dinosaurs (the saurischians). Being herbivores that ...
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Ornithischia ( /ɔrnɨˈθɪskiə/ or-ni-THISS-kee-ə) or Predentata is an extinct order of beaked, herbivorous dinosaurs. The name ornithischia is derived from the Greek ornitheos (ορνιθειος) meaning 'of a bird' and ischion (ισχιον) meaning 'hip joint'. They are known as the 'bird-hipped' dinosaurs because of their bird-like hip structure, even though birds actually descended from the 'lizard-hipped' dinosaurs (the saurischians). Being herbivores that sometimes lived in herds, they were more numerous than the saurischians. They were prey animals for the theropods and were smaller than the sauropods.
The Dinosauria superorder was divided into the two orders Ornithischia and Saurischia by Harry Seeley in 1887. This division, which has generally been accepted, is based on the evolution of the pelvis into a more bird-like structure (although birds did not descend from these dinosaurs), details in the vertebrae and armor and the possession of a 'predentary' bone. The predentary is an extra bone...
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