Coelophysis bauri ( Cope, 1887 )

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 55-56

Coelophysis bauri ( Cope, 1887) , sensu Colbert, 1989 (fig. 12J)

AGE: Late Norian–?Rhaetian, Late Triassic ( Heckert et al., 2008).

OCCURRENCE: Coelophysis Quarry , ‘‘siltstone member’’ of the Chinle Formation, Ghost Ranch, northern New Mexico.

HOLOTYPE: AMNH 7224, complete skeleton missing the tail (the tail is reconstructed from other individuals).

REFERRED MATERIAL: AMNH 7223 (see Colbert, 1989) and any coelophysoid material from the Coelophysis Quarry , including CM 31374, a complete skull.

REMARKS: Coelophysis bauri refers only to the small theropod collected from the Coelophysis Quarry at Ghost Ranch. Even though it was cited as represented by a thousand skeletons ( Schwartz and Gillette, 1994), few of the original specimens are fully prepared, and all of the specimens were subjected to crushing and distortion. Despite the distortion, Coelophysis remains the most completely known basal theropod available for study.

Coelophysis differs from Eoraptor , Herrerasaurus , and Staurikosaurus in the more elongated dorsal vertebrae, five fused sacral vertebrae, dolichoiliacic ilium, presence of a small lateral projection on the distal end of the tibia, and the functionally tridactyl foot with a metatarsal I that is attached to metatarsal II and does not reach the ankle joint. It differs from Gojirasaurus in the relatively lower neural spines of the dorsal vertebrae and the significantly smaller size, from Liliensternus in the absence of a broad ridge that extends from the posterior end of the diapophyses to the posterior end of the vertebral centra in cervical vertebrae and the smaller size, from Procompsognathus in the larger overall size and the lower metatarsal III: tibia ratio, from Shuvosaurus in the lack of any of the derived cranial features of the latter taxon, and from the slightly younger, but very similar Syntarsus in the lack of a postnasal fenestra. (based on Padian 1986, Colbert, 1989, AMNH 7223 and 7224).

KEY REFERENCES: Colbert, 1989; Rauhut, 2003; Nesbitt et al., 2006.