Hollow in Form, But Not Substance

©Jeff Martz via National Park Service

Just to note, before we really begin, how interesting the name is, Coelophysis refers to the bones of the animal while the specific epithet (bauri) honors an anatomist who was at the time working with Marsh; this is interesting because the animal was named by Cope (Ceolophysis in 1889 from the original Coelurus Cope 1887) who described Baur as "the distinguished comparative anatomist of New Haven" while stating that he could not agree with Marsh on the genus being placed in any known order. Backhanded dismissals of other scientists aside, Coelophysis bauri has proven to be a difficult animal to pin down. As an early dinosaur of the Triassic, Coelophysis has many primitive characters as well as some traits that are early building blocks of all theropod dinosaurs. These include, in part, bone composition as well as primitive traits in the forelimbs and hindlimbs, and a long narrow head filled with serrated teeth. Primitively, the mouth is filled slightly more than halfway with teeth; the number of teeth and extension of their length along the jaw would be reduced as theropods evolved further. The lacrimal was devoid of ornamentation as well but some was discovered on the nasal; a primitive trait in comparison to more derived theropods. Coelophysis was also relatively small for a dinosaur as it was the size of a large dog at approximately 9.8 feet (3 meters) and around 3 feet (1 meter) tall at the shoulder. Peculiarly, Coelophysis is known to have fused clavicles, or a furcula, a trait usually seen in birds and bird-like dinosaurs. The inclusion of the furcula this early in dinosaur history is quite interesting and important in the development of theropods and birds.