Deinodon


Deinodon is a dubious tyrannosaurid dinosaur genus containing a single species, Deinodon horridus. D. horridus is known only from a set of teeth found in the Late Cretaceous Judith River Formation of Montana and named by paleontologist Joseph Leidy in 1856. These were the first tyrannosaurid remains to be described and had been collected by Ferdinand Vandeveer Hayden. The teeth of Deinodon were slightly heterodont, and the holotype of Aublysodon can probably be assigned to Deinodon.

History and classification

It is likely that the fossilized teeth of D. horridus belonged to the dinosaur later identified as Gorgosaurus libratus. In a 1922 study, William Diller Matthew & Barnum Brown found that the teeth of D. horridus and G. libratus were indistinguishable from each other, and that they almost certainly belonged to the same species. However, because D. horridus was not yet known from any skeletal remains, they refrained from formally declaring them to be synonyms. In a 1970 review, Dale Russell stated that because the teeth of D. horridus could not be distinguished from either G. libratus or his newly described species Daspletosaurus torosus, it must be considered a nomen vanum. Since Russell published his opinion, most researchers have regarded Deinodon as a nomen dubium, though some have argued that since Deinodon and Gorgosaurus cannot be distinguished, they should be synonymized with D. horridus as the valid name for "Gorgosaurus" skeletons. Additionally, several researchers have agreed that the genus Aublysodon, should also be considered a synonym of Deinodon, since it is based on incisor teeth that likely come from the same animal. Lambe went further, and said that as originally named, Deinodon was not preoccupied, and instead, regarded Aublysodon as a nomen nudum.

Description

Deinodon is known from a few, slightly heterodont teeth.
A few phalanges, and a metatarsal with fragments of others, were found to be possibly assignable to D. horridus by Lambe in 1902.

List of species and synonyms

Numerous species were referred to the genus Deinodon in the past. However, because most researchers now consider the genus and its type species nomina dubia, any additional species referred to the genus cannot be supported.
NameAuthorYearCombination authorCombination yearStatusNotes
Deinodon horridusLeidy1856Leidy1856Nomen dubium, type species
Deinodon explanatusCope1876Lambe1902Reclassified as Dromaeosaurus explanatus nomen dubiumOriginally Laelaps explanatus
Deinodon falculusCope1876Osborn1902Reclassified as Dromaeosaurus falculus nomen dubiumOriginally Laelaps falculus
Deinodon incrassatusCope1876Osborn1902Nomen dubiumOriginally Laelaps incrassatus
Deinodon lateralisCope1876Hay1902Synonym of Deinodon horridusOriginally Aublysodon lateralis
Deinodon cristatusCope1877Osborn1902Synonym of Troodon formosusOriginally Laelaps cristatus
Deinodon hazenianusCope1877Osborn1902Nomen dubiumOriginally Laelaps hazenianus
Deinodon laevifronsCope1877Osborn1902Reclassified as Dromaeosaurus laevifronsOriginally Laelaps laevifrons
Deinodon amplusMarsh1892Hay1902Reclassified as Aublysodon amplusOriginally Aublysodon amplus
Deinodon cristatusMarsh1892Hay1902Reclassified as Aublysodon cristatusOriginally Aublysodon cristatus
Deinodon grandisMarsh1890Osborn1916Synonym of Deinodon horridusOriginally Ornithomimus grandis
Deinodon sarcophagusOsborn1905Matthew & Brown1922Reclassified as Albertosaurus sarcophagusOriginally Albertosaurus sarcophagus
Deinodon libratusLambe1914Matthew & Brown1922Synonym of Gorgosaurus libratusOriginally Gorgosaurus libratus
Deinodon arctunguisParks1928Kuhn1939Synonym of Albertosaurus sarcophagusOriginally Albertosaurus arctunguis
Deinodon novojiloviMaleev1955Maleev1964Synonym of Tarbosaurus bataarOriginally Gorgosaurus novojilovi
Deinodon sternbergiMatthew & Brown1923Kuhn1965Synonym of Gorgosaurus libratusOriginally Gorgosaurus sternbergi
Deinodon periculosusRiabinin1930Kuhn1965Synonym of Tarbosaurus periculosusOriginally Albertosaurus periculosus
Deinodon lancensisGilmore1946Kuhn1965Reclassified as Nanotyrannus lancensisOriginally Gorgosaurus lancensis
Deinodon lancinatorMaleev1955Kuhn1965Synonym of Tarbosaurus bataarOriginally Gorgosaurus lancinator
Deinodon kenabekidesHay1899Olshevsky1995Synonym of Deinodon horridusOriginally Dryptosaurus kenabekides