Open Paleo

Brachyceratops

Gilmore, 1914 BRAK-i-SER-a-tops Nomen dubium

From Greek brachys (βραχύς) meaning 'short', Greek keras (κέρας) meaning 'horn', and Greek ops (ὤψ) meaning 'face'. Full meaning: 'short horned face'.

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

Brachyceratops is a dubious genus of ceratopsian dinosaur from the late Cretaceous Period of Montana, United States. Brachyceratops has historically been known from juvenile remains, with one specimen having since been re-classified as Rubeosaurus ovatus. Sampson and colleagues (1997) and McDonald (2011) identify the type material as juvenile centrosaurines, but because the holotype is too incomplete and juvenile to preserve diagnostic features, they regard Brachyceratops as a nomen dubium.

Species

Brachyceratops montanensis Gilmore, 1914 Nomen dubium

Type species

Named for the provenance of the holotype from Montana, United States.

Holotype
USNM 7951 , National Museum of Natural History, Smithsonian Institution
Material
Disarticulated skull (nasals, prefrontals, postfrontals, postorbitals, premaxillaries, maxillaries, lachrymal, alisphenoid, exoccipital) with provisionally associated fragmentary frill, right dentary, and predentary
Horizon
upper Two Medicine Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Milk River, Blackfeet Indian Reservation, Montana, United States

References

  1. Gilmore, C. W. (1914). A new ceratopsian dinosaur from the Upper Cretaceous of Montana, with note on Hypacrosaurus. Smithsonian Miscellaneous Collections 63(3): 1-10. gilmore1914a
  2. Gilmore, C. W. (1917). Brachyceratops, a ceratopsian dinosaur from the Two Medicine Formation of Montana, with notes on associated fossil reptiles. United States Geological Survey Professional Paper 103: 1-45. United States Geological Survey.

    Comprehensive osteological monograph of Brachyceratops montanensis based on juvenile material from a Two Medicine Formation bone bed, including a formal diagnosis and the first skeletal restoration.

    gilmore1917a
  3. Sampson, S. D.; Ryan, M. J.; Tanke, D. H. (1997). Craniofacial ontogeny in centrosaurine dinosaurs (Ornithischia: Ceratopsidae): taphonomic and behavioral implications. Zoological Journal of the Linnean Society 121: 293-337. Oxford University Press (OUP). doi:10.1111/j.1096-3642.1997.tb00340.x

    Classifies Brachyceratops montanensis as a nomen dubium based on its juvenile craniofacial morphology.

    sampson1997a
  4. McDonald, A. T. (2011). A subadult specimen of Rubeosaurus ovatus (Dinosauria: Ceratopsidae), with observations on other ceratopsids from the Two Medicine Formation. PLOS ONE 6(8): e22710. Public Library of Science (PLoS). doi:10.1371/journal.pone.0022710

    Regards Brachyceratops as a nomen dubium because its holotype is too incomplete and juvenile to preserve diagnostic features, and thus not a senior synonym of Rubeosaurus.

    mcdonald2011b
  5. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Lists Brachyceratops among nomina dubia, as unidentifiable juvenile ceratopsid remains.

    jones2026a