Open Paleo

Apatodon

Marsh, 1877 Nomen dubium

From Greek 'apate' ('deceit') and 'odon' ('tooth'), for the original misidentification of the specimen as the jaw of a mammal.

Apatodon is a dubious genus of dinosaur that may have been a theropod. The type, and only species, A. mirus, was named in 1877 by Othniel Charles Marsh. It was found in the Late Jurassic-aged Morrison Formation of Colorado.

Species

Apatodon mirus Marsh, 1877 Nomen dubium

Type species

From Latin 'mirus' ('wonderful', 'astonishing'), for the unexpected character of the specimen as Marsh interpreted it.

Holotype
Not catalogued (lost)
Material
Weathered fragment of a dinosaurian vertebra, from the neural spine, originally described as a portion of a lower jaw with the last molar in place.
Horizon
Early Jurassic–Early Cretaceous
Locality
Rocky Mountain region, United States Where the type came from was never recorded. Marsh (1877) gives only the Rocky Mountain region and a horizon of Lower Cretaceous or Jurassic, and Chure (2000) reports the holotype lost and repeats the same phrase. The Morrison Formation and a Colorado attribution appear in later compilations without stated support.

References

  1. Marsh, O. C. (1877). Notice of some new vertebrate fossils. American Journal of Science s3-14(81): 249-256. American Journal of Science (AJS). doi:10.2475/ajs.s3-14.81.249

    Erects the genus and species on a fragment from the Rocky Mountain region, interpreting it as a mammalian lower jaw and giving the horizon as Lower Cretaceous or Jurassic.

    marsh1877d
  2. Chure, D. J. (2000). A new species of Allosaurus from the Morrison Formation of Dinosaur National Monument (UT-CO) and a revision of the theropod family Allosauridae. Doctoral thesis, Columbia University.

    Rejects the referral to Allosaurus as unargued, accepts the fragment as a dinosaur vertebra, and treats the species as a nomen dubium at Dinosauria incertae sedis.

    chure2000a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Lists the genus among dubious theropods, records the material as a vertebral shard now lost, and gives the Morrison Formation occurrence.

    jones2026c
  4. Molina-Pérez, R.; Larramendi, A. (2019). Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Princeton University Press.

    Notes that the specimen was lost and never illustrated, so the referral to Allosaurus cannot be confirmed.

    molina-pérez2019a
  5. Olshevsky, G. (1991). A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia. Mesozoic Meanderings 2: 1-196.

    Source of the referral to Allosaurus, listed without supporting argument.

    olshevsky1991a