Open Paleo

Sierraceratops

Dalman et al., 2021 see-EH-ruh-SERR-uh-tops

Named after Sierra County, New Mexico, where fossils were found, combined with Greek keras, "horn", and ops, "face" — means "Sierra horned face"

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

Sierraceratops is a genus of chasmosaurine ceratopsian from the Late Cretaceous Hall Lake Formation of New Mexico, United States. The genus contains a single species, Sierraceratops turneri, known from a partial skeleton discovered in 1997.

Diagnosis

  1. Posterior episquamosals small and triangular; lateral episquamosals low and long with width nearly four times their length
  2. Median parietal bar with D-shaped cross-section, bar approximately as deep as wide
  3. Postorbital horncore short, robust, and strongly mediolaterally compressed
  4. Jugal with two pronounced anterior flanges: one ventral to the jugal/maxilla contact, one anterior to the epijugal contact
  5. Jugal with two processes for articulation with the epijugal horncore: anteroventral (long) and posteroventral (short)
  6. Epijugal horncore massive, pyramid-shaped, and longer than tall

Species

Sierraceratops turneri Dalman et al., 2021

Type species

Named for Ted Turner, founder of CNN, on whose Armendaris ranch in New Mexico the holotype fossils were discovered.

Holotype
NMMNH P-76870 , New Mexico Museum of Natural History and Science
Material
Incomplete skeleton: premaxilla, jugal, epijugal, quadratojugal, quadrate, pterygoid, postorbital horncore, squamosal, partial dentary, cervical vertebrae, dorsal vertebrae, sacrum, dorsal ribs, scapulocoracoid, ulna, ilium, ischial peduncle, manual ungual phalanx
Horizon
Hall Lake Formation, Campanian–Maastrichtian, Late Cretaceous , 83.6–66.0 million years ago
Locality
NMMNH Locality 3650, Armendaris Ranch, New Mexico, United States

References

  1. Dalman, S. G.; Lucas, S. G.; Jasinski, S. E.; Longrich, N. R. (2021). Sierraceratops turneri, a new chasmosaurine ceratopsid from the Hall Lake Formation (Upper Cretaceous) of south-central New Mexico. Cretaceous Research 130. Elsevier BV. doi:10.1016/j.cretres.2021.105034 dalman2021b
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate.

    jones2026a