as an "animal about as large as a wolf, and probably carnivorous". Coelurus would prove to be the first named small theropod from the Morrison Formation, although at the time Marsh was not certain that it was a dinosaur. He returned to it in 1881 and provided illustrations of some bones, along with putting it in a new order (Coeluria) and family (Coeluridae). From there, the story becomes more complex. Apparently, the skeleton was scattered throughout the quarry, with the remains being recovered from September 1879 to September 1880. Marsh elected to place some of the material in a new species, C. agilis, on the strength of a pair of fused pubic bones he thought belonged to an animal three times the size of C. fragilis. He returned to the genus in 1888 to add C". gracilis, based on unknown remains only represented today by a single claw bone pertaining to a small theropod from the Early Cretaceous Arundel Formation of Maryland. This species is not currently accepted as representing Coelurus in reviews of the genus, but has not been given its own genus. Despite their professional animosity, Cope also assigned species to Coelurus; in 1887, he named fossils from the Late Triassic of New Mexico as C. bauri and C. longicollis. He later gave them their own genus, Coelophysis. In 1903, Henry Fairfield Osborn named a second genus of small theropod from the Morrison Formation, Ornitholestes. This genus was based on a partial skeleton from Bone Cabin Quarry, north of Como Bluff. Ornitholestes became intertwined with Coelurus in 1920, when Charles Gilmore, in his influential study of theropod dinosaurs, concluded that the two were synonyms. This was followed in the literature for decades. The two genera were not formally compared, however, nor was there a full accounting of what actually belonged to Coelurus, until John Ostrom's study in 1980. Gilmore had suspected that C. fragilis and C. agilis were the same, but Ostrom was able to demonstrate this synonymy. This greatly expanded the known material pertaining to C. fragilis, and Ostrom was able to demonstrate that Ornitholestes was quite different from Coelurus. At the time, Dale Russell had proposed that C. agilis was a species of Elaphrosaurus based on the incomplete information then published; Ostrom was also able to demonstrate that this was not the case. Additionally, he showed that one of the three vertebrae Marsh had illustrated for