Open Paleo

Colepiocephale

Sullivan, 2003 ko-lep-ee-o-SEF-uh-lee

From Greek kolepion ('knuckle') + kephale ('head'), meaning 'knucklehead', referring to the distinctive domed skull.

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

Colepiocephale is a genus of pachycephalosaurid dinosaur from Late Cretaceous (middle Campanian stage) deposits of Alberta, Canada. It was collected from the Foremost Formation. The type species, C. lambei, was originally described by Sternberg in 1945 as Stegoceras lambei, and later renamed by Sullivan in 2003. C. lambei is a small domed pachycephalosaur known only from incomplete frontoparietal domes. A 2009 redescription by Schott and colleagues showed that the posteromedial extension of the parietal is broken off in every specimen and that the supratemporal fenestrae remained open, refuting earlier interpretations of a reduced occiput and ontogenetically lost squamosals; the genus is now diagnosed chiefly by features of the dome, including prominent, columnar supraorbital lobes and a narrow, high frontonasal boss.

Diagnosis

  1. Frontoparietal dome reaching its greatest width near the posterior margin of the sutural surface for the postorbital.
  2. Inflated parietal region of the dome overhanging the anterior margin of the supratemporal fenestrae.
  3. Sutural surface for the postorbital highly arched, producing a pronounced diastema between the sutural surfaces for the postorbital and posterior supraorbital.
  4. Diastema accompanied by a distinct indentation in the lateral wall of the dome.
  5. Frontonasal boss narrow and high, flanked at its posterior end by the supraorbital lobes.
  6. Supraorbital lobes highly distinct and columnar (pillar-like in larger specimens).

Species

Colepiocephale lambei Sullivan, 2003

Type species

Named for the deceased Canadian paleontologist Lawrence M. Lambe.

Holotype
CMN 8818 , Canadian Museum of Nature
Material
Nearly complete frontoparietal dome, missing the posteromedial extension of the parietal and all peripheral skull bones.
Horizon
Foremost Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
South Saskatchewan River, 4.8 km below Bow Island Ferry, Alberta, Canada

References

  1. Sullivan, R. M. (2003). Revision of the dinosaur Stegoceras Lambe (Ornithischia, Pachycephalosauridae). Journal of Vertebrate Paleontology 23(1): 181-207. Informa UK Limited. doi:10.1671/0272-4634(2003)23[181:rotdsl]2.0.co;2 sullivan2003b
  2. Schott, R. K.; Evans, D. C.; Williamson, T. E.; Carr, T. D.; Goodwin, M. B. (2009). The anatomy and systematics of Colepiocephale lambei (Dinosauria: Pachycephalosauridae). Journal of Vertebrate Paleontology 29(3): 771-786. Informa UK Limited. doi:10.1671/039.029.0329

    Anatomical redescription of all known C. lambei material; reinterprets the parietosquamosal region (open supratemporal fenestrae, squamosals unpreserved) and revises the diagnosis.

    schott2009a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate, and the appearance features.

    jones2026a