Origins and Evolution of Ornithischian Dinosaurs

  title={Origins and Evolution of Ornithischian Dinosaurs},
  author={Richard A. Thulborn},
Recent discoveries in the red beds of the Upper Trias have shed light on the history of the ornithischian dinosaurs. It is suggested that these dinosaurs had a monophyletic origin among advanced pseudosuchian thecodonts. Development of their rather bird-like pelvis involved backwards rotation of the pubis and subsequent growth of a prepubis. A conservative stock of primitive-looking hypsilophodonts, which persisted from the late Trias through the Cretaceous, lay at the core of ornithischian… CONTINUE READING