Open Paleo

Protoceratopsidae

Granger & Gregory, 1923 Type genus Protoceratops

Its genera lived 85.7–66.0 million years ago Late Cretaceous
Late Cretaceous stages

Protoceratopsidae is a family of small, primitive horned dinosaurs from the Late Cretaceous of Asia, with most specimens recovered from China and Mongolia and dating to roughly 75 to 71 million years ago. Its members were modest in size, around 1 to 2.5 meters long, and included Protoceratops, Bagaceratops, and Breviceratops. Like all ceratopsians they were herbivores equipped with a hooked beak and slicing tooth batteries, but their bony frill and horns were far smaller than those of the later, larger ceratopsids. Distinctive features include a wedge-shaped snout carrying tall, narrow nostrils set high on the skull, an unusually small antorbital fenestra, and a maxillary sinus not seen in other ceratopsians. Along the backbone, the tail bore very long neural spines that made it tall and flattened from side to side. The concept has narrowed over time, with genera such as Leptoceratops and Montanoceratops now assigned instead to the mostly North American Leptoceratopsidae.

Diagnosis

  1. Solid (unfenestrated or minimally fenestrated) parietosquamosal frill
  2. Deep, narrow snout with a prominent nasal horn or boss in some members
  3. Reduced or absent premaxillary dentition
  4. Tall neural spines over the sacrum and tail

Genera placed directly in Protoceratopsidae

  • Bagaceratops Maryańska & Osmólska, 1975 Campanian (83.6–72.2 Ma)Mongolia
  • Bainoceratops Disputed Tereshchenko & Alifanov, 2003 Campanian (83.6–72.2 Ma)Mongolia
  • Breviceratops Kurzanov, 1990 Santonian–Maastrichtian (85.7–66.0 Ma)Mongolia
  • Protoceratops Granger & Gregory, 1923 Campanian (83.6–72.2 Ma)Mongolia

References

  1. Granger, W.; Gregory, W. K. (1923). Protoceratops andrewsi, a pre-ceratopsian dinosaur from Mongolia. American Museum Novitates 72: 1-9.

    Named Protoceratopsidae.

    granger1923a
  2. Madzia, D.; Arbour, V. M.; Boyd, C. A.; Farke, A. A.; Cruzado-Caballero, P.; Evans, D. C. (2021). The phylogenetic nomenclature of ornithischian dinosaurs. PeerJ 9: e12362. doi:10.7717/peerj.12362

    Defined Protoceratopsidae as the largest clade containing Protoceratops andrewsi but not Ceratops montanus, Leptoceratops gracilis or Triceratops horridus.

    madzia2021a
  3. 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

    Revised the protoceratopsids of the Baruungoyot Formation, synonymizing several Gobi genera with Bagaceratops.

    czepiński2019a