Original paper
The crocodilian tarsus and the evolution of the archosauria
Tarsitano, S.
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen Band 164 Heft 1-2 (1982), p. 199 - 202
9 references
published: Dec 22, 1982
DOI: 10.1127/njgpa/164/1982/199
ArtNo. ESP155016401045, Price: 29.00 €
Abstract
It has long been recognized that there are two major methods of terrestial locomotion in archosaurian reptiles, quadrupedal and bipedal locomotion (Romer, 1966). Quadrupedal locomotion is considered primitive for all reptiles while bipedal locomotion is derived. The earliest members of the Archosauria, the Crocodilia and the Thecondontia, were mostly quadrupedal. It is believed by some (Romer, 1956) that some of the thecodonts, in particular the Pseudosuchia, may have had bipedal tendencies. Until rcently (Tarsitano, PH. D. thesis and Hecht & Tarsitano, in press), the only characters usually associated with bipedalism in the Archosauria were the disparity in size between the fore and hindlimbs, a mesotarsal ankle joint and an obivious upright stance where the hindlimbs were nearly underneath the pelvis. The true bipedal archosaurs are members of the two orders of dinosaurs, the Ornithischia and the Saurischia and a derived archosaurian group, the Aves. All carnivorous saurischian dinosaurs (theropods) were bipedal. There were also bipedal ornithischian dinosaurs such as the amphibious hadrosaurs. All ornithischian dinosaurs were apparently herbivorous.
Keywords
archosaurian reptiles • Crocodilia • Thecondontia • pelvis • bipedal archosaurs • dinosaurs • hadrosaurs • herbivorous