Open Paleo

Aublysodon

Leidy, 1868 Nomen dubium

Commonly rendered 'backward-flowing tooth'; Leidy gave no explanation of the name when proposing it.

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

Aublysodon is a dubious genus of carnivorous dinosaurs known only from the Judith River Formation in Montana, which has been dated to the late Campanian age of the late Cretaceous period (about 75 million years ago).

Species

Aublysodon mirandus Leidy, 1868 Nomen dubium

Type species

Lectotype
ANSP 9535 , Academy of Natural Sciences of Philadelphia
Material
Single premaxillary tooth with a chisel-shaped crown covered by a thin coat of enamel, without crenulations, the posterior ridge grooved and the apex worn anteriorly.
Notes
Leidy (1868) founded the species on parts of three teeth from the Judith River material Leidy had earlier placed in Deinodon. Marsh (1892) restricted it to the single tooth figured in Leidy's figures 41 to 45, leaving the other two with Deinodon horridus and so separating the two genera. Holtz (1994) gives the restricted type as ANSP 9535.
Horizon
Judith River Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Montana, United States

References

  1. Leidy, J. (1868). Remarks on a jaw fragment of Megalosaurus. Proceedings of the Academy of Natural Sciences of Philadelphia 20: 197-200.

    Erects the genus and species on parts of three Judith River teeth that the author had previously referred to Deinodon.

    leidy1868b
  2. 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

    Restricts the type of the species to a single tooth, separating it from Deinodon horridus, and doubts that some of the teeth are dinosaurian at all.

    marsh1892b
  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, correcting the error on which the substitution of Aublysodon rested.

    hay1899a
  4. Holtz, T. R. (1994). The phylogenetic position of the Tyrannosauridae: implications for theropod systematics. Journal of Paleontology 68: 1100-1117.

    Gives the restricted type of the species as ANSP 9535 and tabulates the formations to which material has been referred.

    holtz1994a
  5. 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.

    Names Deinodon horridus on the Judith River teeth from which the type of Aublysodon mirandus was later separated.

    leidy1856b
  6. Weishampel, D. B.; Dodson, P.; Osmólska, H. (eds.) (2004). The Dinosauria, Second Edition. University of California Press, Berkeley.

    Lists the genus and its species among tyrannosaurid nomina dubia, and questions whether unserrated teeth of this form are diagnostic at all.

    weishampel2004a
  7. Carr, T. D.; Williamson, T. E.; Schwimmer, D. R. (2005). A new genus and species of tyrannosauroid from the Late Cretaceous (Middle Campanian) Demopolis Formation of Alabama. Journal of Vertebrate Paleontology 25(1): 119-143. Informa UK Limited. doi:10.1671/0272-4634(2005)025[0119:angaso]2.0.co;2

    States that the authors consider the genus an invalid taxon.

    carr2005a
  8. Carr, T. D.; Williamson, T. E. (2010). Bistahieversor sealeyi, gen. et sp. nov., a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea. Journal of Vertebrate Paleontology 30(1): 1-16. Informa UK Limited. doi:10.1080/02724630903413032

    Records that the referral of OMNH 10131 to Aublysodon cf. A. mirandus was later falsified.

    carr2010a
  9. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Treats the genus as a dubious tooth taxon and reports the competing referrals to Daspletosaurus and Deinodon.

    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 derivation of its type from the Deinodon material.

    olshevsky1991a