Open Paleo

Bainoceratops

Tereshchenko & Alifanov, 2003 Disputed

From the Bain-Dzak locality (Mongolian for "rich-in-saxaul", the Mongolian name for the Flaming Cliffs of the Gobi Desert) and Greek keratops (horned face); meaning "Bain-Dzak horned face".

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

Bainoceratops is a genus of ceratopsian dinosaur from the late Campanian in the Late Cretaceous. The type species is B. efremovi. Its fossils were found in southern Mongolia in the Djadokhta Formation.

Under dispute

Bainoceratops efremovi is based only on vertebrae. Makovicky and Norell (2006) suggested it may be a junior synonym, its vertebral features falling within the variation of Protoceratops, and Czepiński (2019) likewise notes it may fall within the variation of P. andrewsi; neither formally synonymized it. Kept valid pending consensus.

Diagnosis

  1. Presacral vertebral centra with concave cranial surfaces and flat caudal surfaces.
  2. Diapophyses of the ninth dorsal vertebra circular in cross section; interprezygapophyseal spaces of dorsals 9 and 10 narrow.
  3. Synapophyseal facets of the posteriormost dorsal vertebra sculptured with a median crest.

Species

Bainoceratops efremovi Tereshchenko & Alifanov, 2003 Disputed

Type species

Named after Ivan Antonovich Efremov (1908-1972), the Soviet paleontologist and writer who led the early Soviet expeditions to the Gobi Desert.

Holotype
PIN 614-33 , Paleontological Institute, Russian Academy of Sciences
Material
Postcranial vertebral series including cervicals 6, 7, 9; thoracics ?1, ?5-7, 9-13; sacral 8; and caudals 1-3, ?10-11, ?18-19. No cranial material.
Horizon
Bayn Dzak Member, Djadokhta Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Bayan Zag, Ömnögovi, Mongolia

References

  1. Tereshchenko, V. S.; Alifanov, V. R. (2003). Bainoceratops efremovi, a new protoceratopid dinosaur (Protoceratopidae, Neoceratopsia) from the Bain-Dzak locality (south Mongolia). Paleontological Journal 37(3): 293-302. Pleiades Publishing Ltd.

    Erects Bainoceratops efremovi on PIN 614-33, a postcranial vertebral series from the Djadokhta Formation at Bayan Zag (southern Gobi, Mongolia).

    tereshchenko2003a
  2. Makovicky, P. J.; Norell, M. A. (2006). Yamaceratops dorngobiensis, a New Primitive Ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia. American Museum Novitates 3530: 1-42. American Museum of Natural History (BioOne sponsored). doi:10.1206/0003-0082(2006)3530[1:ydanpc]2.0.co;2

    Suggested Bainoceratops may be a junior synonym, its vertebrae falling within the variation of Protoceratops.

    makovicky2006a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Lists Bainoceratops as a subjective synonym of Protoceratops andrewsi.

    jones2026a
  4. Czepiński, Ł. (2019). Ontogeny and variation of a protoceratopsid dinosaur Bagaceratops rozhdestvenskyi from the Late Cretaceous of the Gobi Desert. Historical Biology 32: 1394-1421. doi:10.1080/08912963.2019.1593404 czepiński2019a