In 1871, Cope identified a second species of North American "Liodon" based on several vertebrae and limb fragments, which he named "Liodon dyspelor". The fossils came to Cope under the label as having been collected by an army doctor named William B. Lyon at Fort McRae, New Mexico. However, a 1997 study led by David C. Parris of the New Jersey State Museum found that the chemical composition of the fossil did not match any known geological deposit in New Mexico and is instead identical to that of the Niobrara Formation; the study speculated from examinations of multiple letters between Lyon and the Smithsonian Institution that the "Liodon dyspelor" fossils were actually recovered from somewhere in Western Kansas and were mislabeled as being collected by Lyon in New Mexico (who was shipping a different fossil from Fort McRae around the same time) during transit. The type specimen of the taxon is split between two museums; some of the vertebrae went to Cope's American Museum of Natural History as AMNH 1580 while the rest were sent to the Smithsonian as USNM 41.