Open Paleo

Montanoceratops

Sternberg, 1951 mon-TAN-o-SER-a-tops /mɒnˌtænoʊˈsɛrətɒps/

From 'Montana' (the U.S. state where it was first discovered) combined with Greek 'keras' (horn) and 'ops' (face); meaning 'Montana horned face'

83.6–66.0 million years ago Campanian–Maastrichtian, Late Cretaceous
Late Cretaceous stages

Montanoceratops is an extinct genus of small ceratopsian dinosaur that lived approximately 70 million years ago during the latter part of the Cretaceous Period in what is now Montana and Alberta. Montanoceratops was a small sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated 2.5 m (8.2 ft) in length and 170 kg (370 lb) in body mass.

Diagnosis

  1. Well-developed nasal horncore on the nasals, absent in Leptoceratops
  2. Squamosal extended well behind the head of the quadrate, helping form a parietosquamosal crest that Leptoceratops lacks
  3. Dentary relatively long with a straight ventral border, versus the short dentary with rounded ventral border in Leptoceratops
  4. Caudal neural spines very long, some more than five times the height of the corresponding centrum, versus two to two-and-a-half times in Leptoceratops
  5. Splenial heavier and more elongate, with a more massive anterior end than in Leptoceratops

Species

Montanoceratops cerorhynchus Brown & Schlaikjer, 1942

Type species

From Ancient Greek 'keras' ('horn') and 'rhynchos' ('snout' or 'beak'), meaning 'horn-snouted', referring to what was originally interpreted as a nasal horn.

Holotype
AMNH 5464 , American Museum of Natural History
Material
Partial skull and jaws; complete cervical, dorsal, and sacral vertebrae; 13 caudals; ribs; near-complete pelvis; both femora; left tibia, fibula, astragalus; foot phalanges.
Horizon
lower St. Mary River Formation, Campanian–Maastrichtian, Late Cretaceous , 83.6–66.0 million years ago
Locality
Near Buffalo Lake, Blackfeet Indian Reservation, Montana, United States

References

  1. Brown, B.; Schlaikjer, E. M. (1942). The skeleton of Leptoceratops with the description of a new species. American Museum Novitates 1169: 1-15.

    Original description of the holotype (AMNH 5464), as Leptoceratops cerorhynchus.

    brown1942a
  2. Sternberg, C. M. (1951). Complete skeleton of Leptoceratops gracilis Brown from the Upper Edmonton Member on Red Deer River, Alberta. National Museum of Canada Bulletin 123: 225-255. Natural Resources Canada/CMSS/Information Management. doi:10.4095/105059

    Erected the genus Montanoceratops for the species.

    sternberg1951a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a