Open Paleo

Regaliceratops

Brown & Henderson, 2015 ree-guh-li-seh-ruh-tops

From Latin regalis (royal) and Greek keras (horn) and ops (face); meaning "Royal horned face".

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Regaliceratops is a monospecific genus of chasmosaurine ceratopsid dinosaur from Alberta, Canada that lived during the Late Cretaceous (middle Maastrichtian stage, 68.5 to 67.5 Ma) in what is now the St. Mary River Formation. The type and only species, Regaliceratops peterhewsi, is known only from an adult individual with a nearly complete skull lacking the lower jaw, which was nicknamed "Hellboy". Regaliceratops was named in 2015 by Caleb M. Brown and Donald M. Henderson. Regaliceratops has an estimated length of 5 meters (16 ft) and body mass of 2 metric tons (2.2 short tons). The skull of Regaliceratops displays features more similar to centrosaurines, which suggests convergent evolution in display morphology in ceratopsids.

Diagnosis

  1. Single, midline epiparietal ossification (P0) rostrodorsally offset from plane of frill, projecting caudal to parietal with triangular cross-section
  2. Prominent midline ridge on parietal confluent with median epiparietal (P0 locus)
  3. Paired epiparietal ossifications (P1-2) long, flat, and roughly pentagonal or spade shaped; largest frill epiossifications in Chasmosaurinae (max 201 mm)
  4. Prominent postorbital ridge running diagonally from supraorbital horncore to base of squamosal
  5. Parietal fenestrae small or subequal in size to orbit
  6. Nasal horncore larger than postorbital horncores; large, steeply sided, one of the tallest in Chasmosaurinae (240-280 mm estimated)

Species

Regaliceratops peterhewsi Brown & Henderson, 2015

Type species

Named for Peter Hews, the geologist who discovered the type specimen along the Oldman River in southwestern Alberta in 2005.

Holotype
TMP 2005.055.0001 , Royal Tyrrell Museum of Paleontology
Material
Nearly complete cranium (skull excluding lower jaw) missing only the rostral bone.
Horizon
upper St. Mary River Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
Waldron Flats, Alberta, Canada

References

  1. Brown, C. M.; Henderson, D. M. (2015). A New Horned Dinosaur Reveals Convergent Evolution in Cranial Ornamentation in Ceratopsidae. Current Biology 25(12): 1641-1648. Elsevier BV. doi:10.1016/j.cub.2015.04.041 brown2015a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

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

    jones2026a