to that date and assigned them to Coelophysis. The Ghost Ranch specimens were so numerous, including many well-preserved and fully articulated specimens, that one of them has since become the diagnostic, or type specimen, for the entire genus, replacing the original, poorly preserved specimen."Syntarsus" rhodesiensis was first described by Raath (1969) and assigned to Podokesauridae. The taxon "Podokesauridae", was abandoned because its type specimen was destroyed in a fire and can no longer be compared to new finds. Over the years paleontologists assigned the genus to Ceratosauridae (Welles, 1984), Procompsognathidae (Parrish and Carpenter, 1986) and Ceratosauria (Gauthier, 1986). In 2004 "Syntarsus" was found to be synonymous with Coelophysis by Tykoski and Rowe (2004). Ezcurra and Novas (2007) and Ezcurra (2007) also concluded that "Syntarsus" was synonymous with Coelophysis. In a phylogenetic analysis by Ezcurra (2017), Megapnosaurus was recovered in a clade with Segisaurus and Camposaurus, supporting the generic distinction of Megapnosaurus. This was supported by Barta and colleagues in 2018, noting that Coelophysis still bears the vestigial 5th metacarpal, a feature absent in Megapnosaurus. Description Coelophysis is known from a number of complete fossil skeletons of the species C. bauri: a lightly built dinosaur that measured up to in length and was more than a meter tall at the hips. Paul (1988) estimated the weight of the gracile form at , and the weight of the robust form at , but later presented a higher estimate of . Coelophysis was a bipedal, carnivorous, theropod dinosaur and a fast and agile runner. Despite being an early dinosaur, the evolution of the theropod body form had already advanced greatly from creatures like Herrerasaurus and Eoraptor. The torso of Coelophysis conforms to the basic theropod body shape, but the pectoral girdle displays some special characteristics: C. bauri had a furcula (wishbone), the earliest known example in a dinosaur. Coelophysis also preserves the ancestral condition of possessing four digits on the hand (manus). It had only three functional digits, the fourth embedded in the flesh of the hand. Coelophysis had narrow hips, forelimbs adapted for grasping prey, and narrow feet. Its neck and tail were long and slender. The pelvis and hindlimbs of C. bauri are also slight variations on the theropod body plan. It has the open acetabulum and straight ankle hinge that define the Dinosauria. The hindlimb ended in a three-toed foot (pes), with a raised hallux. The tail had an unusual