Open Paleo

Deinodon

Leidy, 1856 Nomen dubium

From Greek 'deinos' ('terrible') and 'odon' ('tooth'), for the large serrated teeth on which the genus was founded.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Deinodon is a dubious genus of tyrannosaurid dinosaur containing a single species, Deinodon horridus, which 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 the former.

Species

Deinodon horridus Leidy, 1856 Nomen dubium

Type species

Lectotype
ANSP 9533, ANSP 9534 , Academy of Natural Sciences of Philadelphia
Material
Two fragmentary premaxillary teeth, selected from the series of Judith River teeth on which the species was founded.
Notes
Leidy (1856) founded the species on a series of fragmentary teeth of more than one form. Cope (1866) restricted it to three nonserrated teeth, of which Marsh (1892) later removed one to Aublysodon mirandus, leaving two with this species.
Horizon
Judith River Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Montana, United States

Synonyms

  • Aublysodon horridus junior objective

    Cope substituted Aublysodon for Deinodon in the belief that the latter was preoccupied by the snake genus Dinodon. Hay (1899) showed that it was not, so the combination rests on the same type material as Deinodon horridus.

Synonyms of the genus

Name Type Reason
Dinodon emended spelling Cope (1866) emended the name to Dinodon, which is preoccupied by the snake genus Dinodon Dumeril and Bibron, 1853. Hay (1899) showed the two names have different derivations and that Leidy's original spelling was never preoccupied.

References

  1. Leidy, J. (1856). Notices of remains of extinct reptiles and fishes, discovered by Dr. F. V. Hayden in the bad lands of the Judith River, Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia 8: 72-73.

    Erects the genus and species on a series of fragmentary teeth collected by Hayden in the Judith River badlands.

    leidy1856b
  2. Russell, D. A. (1970). Tyrannosaurs from the Late Cretaceous of western Canada. Publications in Palaeontology 1. National Museum of Natural Sciences, Ottawa. doi:10.5281/zenodo.1040973

    Gives the lectotype as two fragmentary premaxillary teeth and finds it generically unidentifiable.

    russell1970a
  3. Hay, O. P. (1899). On the nomenclature of certain American fossil vertebrates. American Geologist 24: 345-349.

    Shows that Deinodon was never preoccupied by the snake genus Dinodon, so Leidy's original spelling stands.

    hay1899a
  4. Matthew, W. D.; Brown, B. (1922). The family Deinodontidae, with notice of a new genus from the Cretaceous of Alberta. Bulletin of the American Museum of Natural History 46(6): 367-385. doi:10.5281/zenodo.1048848

    Finds nothing in the dentition to separate Gorgosaurus from Deinodon, but holds the identity unproven pending topotypes from the Judith River.

    matthew1922a
  5. Gilmore, C. W. (1946). A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106(13): 1-19.

    Reports that Aublysodon was abandoned on grounds of priority as a synonym of Deinodon.

    gilmore1946a
  6. Carr, T. D. (1999). Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria). Journal of Vertebrate Paleontology 19(3): 497-520. doi:10.1080/02724634.1999.10011161

    Endorses the finding that the lectotype cannot be distinguished from Dinosaur Park material, and records the dissenting view.

    carr1999a
  7. Rauhut, O. W. M. (2003). The interrelationships and evolution of basal theropod dinosaurs. Special Papers in Palaeontology 69: 1-213. The Palaeontological Association.

    States that the type teeth are undiagnostic, so Tyrannosauridae is preferred over Deinodontidae as the family name.

    rauhut2003b
  8. Weishampel, D. B.; Dodson, P.; Osmólska, H. (eds.) (2004). The Dinosauria, Second Edition. University of California Press, Berkeley.

    Lists the species among tyrannosaurid nomina dubia and questions whether it belongs to Gorgosaurus.

    weishampel2004a
  9. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Reports the type teeth as indistinguishable from those of Gorgosaurus or Daspletosaurus, and the genus as widely considered dubious.

    jones2026c
  10. Olshevsky, G. (1991). A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2: 1-196.

    Records the species referred to the genus and the fate of the family name based on it.

    olshevsky1991a
  11. Marsh, O. C. (1892). Notes on Mesozoic vertebrate fossils. American Journal of Science s3-44(260): 171-176. American Journal of Science (AJS). doi:10.2475/ajs.s3-44.260.171 marsh1892b
  12. Cope, E. D. (1866). Discovery of a gigantic dinosaur in the Cretaceous of New Jersey. Proceedings of the Academy of Natural Sciences of Philadelphia 18: 275-279. cope1866a