the same type, it was at first a junior objective synonym of Deinodon horridus, which latter name thus had priority. Cope in 1868 mistakenly thought the name Deinodon was preoccupied by the snake Dinodon and renamed Deinodon horridus into an Aublysodon horridus. If Deinodon really had been preoccupied, this would have made Aublysodon a valid genus. In 1899 Oliver Perry Hay pointed out Cope's mistake; Aublysodon horridus is a junior objective synonym of Deinodon horridus, just as Aublysodon mirandus had been. However, in 1892 Aublysodon became an independent genus when Othniel Charles Marsh further limited its type by choosing a single small nonserrated premaxillary tooth with a D-shaped cross-section, specimen ANSP 9535, as the lectotype of Aublysodon mirandus. The two other teeth, ANSP 9533 and ANSP 9534, remained as the lectotypes of Deinodon horridus. The names were thus separated. The tooth-based taxon Aublysodon was a mystery for a long time since no further skeletal elements were found that could be assigned with certainty to the teeth. In the early twentieth century it was assumed by some workers that it represented a member of the Ornithomimidae when it was not yet known this group was toothless. Lawrence Morris Lambe in 1902 referred the tooth to Struthiomimus; Hay in 1930 renamed A. mirandus into Ornithomimus mirandus, forgetting in that case Aublysodon would have priority. Today it is known that similar teeth are found in juvenile specimens of Daspletosaurus, and it is likely that teeth referred to Aublysodon came from that genus. In October 2000, the type specimen of Aublysodon went missing when being sent by registered mail from the Academy of Natural Sciences of Philadelphia to the Field Museum of Natural History. Because of the presence of Aublysodon-type teeth in other juvenile tyrannosaurines than Daspletosaurus, such as those of Tyrannosaurus, remains of which can also be found in Montana, Thomas Carr no longer considered the name to represent a real biological taxon, but to be a nomen dubium. Referred species Apart from Aublysodon mirandus and A. horridus several other species have been named within the genus. In 1876 Cope created an Aublysodon lateralis, based on specimen AMNH 3956, a tooth of a juvenile tyrannosaur which has been synonymized with Deinodon horridus. In 1892 Marsh named two more species: Aublysodon amplus and Aublysodon cristatus, respectively based on teeth YPM 296 and YPM 297; the latter has also been placed in the genus Deinodon.