Regaliceratops

Genera and Species

Classification: Ceratopsia, Ceratopsidae, Chasmosaurinae

Species: R. peterhewsi, after Peter Hews, who discovered the specimen

Characteristics

Regaliceratops has three well developed horns, although the nose horn is larger than the brow horns. The parietal bone, which forms most of the neck frill, bears a series of massive ossifications along its back edge. Although nearly all of the features of the skull place it within the ‘long frilled, low snouted’ ceratopsids (the subfamily Chasmosaurinae), the frill is quite short, and so superficially resembles that of the ‘short frilled, tall snouted’ ceratopsids (the subfamily Centrosaurinae).

Size

Length: 5 meters (about 16 feet)

Weight: about 1.5 tons

Behavior

Most paleontologists agree that the facial horns and ‘frill’ that projects off the back of the skull of a horned dinosaur was used for display – basically easily seen features that allowed individuals of the same species to recognize each other. Two types of horned dinosaurs lived simultaneously for most of the group’s history: one group had a short frill with a large nasal horn and shorter brow horns (Centrosaurinae), and the other had a long frill with a short nasal horn and longer brow horns (Chasmosaruinae). It is thought that the two types of frill and different horn lengths made it much easier for an individual to distinguish even at a distance. If multiple species possessing each type of frill lived at the same time, then more subtle details of ornamentation of the frill was used to make a more precise identification. Regaliceratops lived at the end of the Cretaceous when many dinosaur species, including all of the short frilled ceratopsids, had become extinct. Regalisaurus took advantage of the fact that the short frilled niche was vacant and available, and evolved a shorter frill, as well as a longer nasal horn, to make it easier for other members of its species to distinguish it from the other long frilled horned dinosaurs that were still around without risk of being confused with a short frilled form.

History of Discovery

The specimen was discovered in 2005 by geologist Peter Hews along the Oldman River in Alberta. The fossil was collected by a team from the Royal Tyrrell Museum. Caleb Brown and Donald Henderson described and named it in 2015.

Paleoenvironment

Most ceratopsids inhabited the low lying coastal plains between a vast interior seaway that covered much of the central part of North America to the east, and the newly formed Rocky Mountains to the west. Regaliceratops was collected much farther to the west than most other ceratopsid remains, and so must have lived far from the coastal plains of the seaway, and closer to the mountains. The climate at this higher altitude would have been cooler and dryer than experienced by most other horned dinosaurs.

References

1. Brown, Caleb M., and Henderson, Donald M. 2015. A new horned dinosaur reveals convergent evolution in cranial ornamentation in ceratopsidae. Current Biology. 25 (online): 1641–8. PMID 26051892. doi:10.1016/j.cub.2015.04.041.
2. Hone, D.W.E. 2015. Evolution: Convergence in dinosaur crests. Current biology 25 (online): 494-496 http://dx.doi.org/10.1016/j.cub.2015.04.051