Open Paleo

Yamaceratops

Makovicky & Norell, 2006 YAH-mah-SEH-ruh-tops

Named after Yama, a Tibetan Buddhist deity, combined with Greek 'keras' meaning 'horn' and 'ops' meaning 'face'

85.7–72.2 million years ago Santonian–Campanian, Late Cretaceous
Late Cretaceous stages

Yamaceratops is a genus of primitive ceratopsian that lived during the Late Cretaceous in what is now Mongolia. The genus contains a single species, Y. dorngobiensis. It was a relatively small dinosaur, with an estimated length of 50 cm (1.6 ft) and weighing around 2 kg (4.4 lb).

Diagnosis

  1. Unkeeled rostral unlike all other Neoceratopsia (optimization-dependent unique trait)
  2. Rostral patterned with anastomosing ridges and grooves
  3. Angular with two tubercles along ventral edge (unique trait)
  4. Subtemporal part of jugal lobate and deeper than suborbital section
  5. Epijugal ossification present

Species

Yamaceratops dorngobiensis Makovicky & Norell, 2006

Type species

Named for the Eastern Gobi (Dorngobi) region of Mongolia, where the holotype was found.

Holotype
IGM 100/1315 , Paleontological Center, Mongolian Academy of Sciences
Material
Partial skull missing premaxillae, rostral, and predentary; much of frill and left cheek and posterior part of left mandible absent
Horizon
Javkhlant Formation, Santonian–Campanian, Late Cretaceous , 85.7–72.2 million years ago
Locality
Khugenetjavkhlant, Dornogovi, Mongolia

Notable specimens

  • MPC-D 100/553

    Paleontological Center, Mongolian Academy of Sciences Found 2014 ontogeny

    Juvenile referred specimen from the Khugenetjavkhlant locality; an immature individual about three years old with an estimated body mass of 1.2 kg, documenting an early growth stage, with long hindlimbs indicating a bipedal posture.

    Son et al. (2022)

References

  1. 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 makovicky2006a
  2. Son, M.; Lee, Y. N.; Zorigt, B.; Kobayashi, Y.; Park, J. Y.; Lee, S.; Kim, S. H.; Lee, K. Y. (2022). A new juvenile Yamaceratops (Dinosauria, Ceratopsia) from the Javkhlant Formation (Upper Cretaceous) of Mongolia. PeerJ 10: e13176. doi:10.7717/peerj.13176 son2022a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the appearance features.

    jones2026a
  4. Eberth, D. A.; Kobayashi, Y.; Lee, Y. N.; Mateus, O.; Therrien, F.; Zelenitsky, D. K.; Norell, M. A. (2009). Assignment of Yamaceratops dorngobiensis and associated redbeds at Shine Us Khudag (eastern Gobi, Dorngobi Province, Mongolia) to the redescribed Javkhlant Formation (Upper Cretaceous). Journal of Vertebrate Paleontology 29(1): 295-302.

    Erects the Javkhlant Formation and assigns the holotype's redbeds to it, placing the site within the Shine Us Khudag exposure.

    eberth2009a