(original) (raw)

TY - JOUR AU - THULBORN, RICHARD A. PY - 1971 DA - 1971/11/01 TI - Origins and Evolution of Ornithischian Dinosaurs JO - Nature SP - 75 EP - 78 VL - 234 IS - 5324 AB - 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 phylogeny. SN - 1476-4687 UR - https://doi.org/10.1038/234075a0 DO - 10.1038/234075a0 ID - THULBORN1971 ER -