Regaliceratops, a recently identified horned dinosaur, captivated paleontologists and the public with its striking head ornamentation. This unique creature offers a glimpse into the diverse forms that roamed ancient Earth.
Unearthing a Royal Horned Face
In 2005, geologist Peter Hews discovered a skull protruding from a cliff along the Oldman River in southwestern Alberta, Canada. The fossil was embedded in siltstone within the St. Mary River Formation. A Royal Tyrrell Museum team excavated the fossil in 2006 and 2008, a challenging task due to its proximity to protected bull trout spawning grounds.
The near-complete skull, missing only the lower jaw, was nicknamed “Hellboy” by paleontologists because the surrounding rock was incredibly hard, making excavation a difficult, multi-year task. In 2015, Caleb M. Brown and Donald M. Henderson named the species Regaliceratops peterhewsi. The genus name, “Regaliceratops,” translates to “royal horned face,” referring to its distinctive, crown-like frill. The species name honors its discoverer, Peter Hews. This dinosaur is classified as a chasmosaurine within the Ceratopsidae family, a group that includes Triceratops.
The Crowned Dinosaur’s Distinctive Look
Regaliceratops possessed unique features that set it apart from other horned dinosaurs. Its most striking characteristic was its large, circular frill, adorned with a series of flat, spade-shaped, and pentagonal bony plates around its edge. This arrangement of plates resembled a crown, inspiring its “royal” name.
Unlike most chasmosaurines, which had long brow horns and a shorter nose horn, Regaliceratops displayed the opposite configuration. It featured a long, prominent horn over its snout and smaller, narrower, forward-curving horns above its eyes. This mix of features, where a chasmosaurine evolved traits seen in the centrosaurine group, represents an example of convergent evolution.
The frill had a prominent midline ridge and a central epiossification projecting towards the snout. The parietal fenestrae, the openings in the frill, were small, similar in size to its eye sockets. These cranial ornaments likely functioned primarily in display or signaling, potentially for mate attraction or species recognition, rather than solely for defense.
Life in Ancient Laramidia
Regaliceratops lived during the Late Cretaceous period, approximately 68.5 to 67.5 million years ago. It inhabited the continent of Laramidia, a long, narrow landmass that formed the western part of North America. This region was characterized by warm, wet coastal plains, bordered by a shallow inland sea to the east and rising mountains to the west.
The St. Mary River Formation indicates an environment that transitioned from brackish to freshwater fluvial and floodplain settings. This landscape likely supported diverse plant life, consistent with Regaliceratops’ herbivorous diet. Like other ceratopsians, it used its beak-like mouth to crop vegetation.
While fossil evidence for Regaliceratops consists of a single skull, insights from other ceratopsians suggest possible behaviors. Many centrosaurines, a group with similar physical traits, are known to have lived in herds, evidenced by mass-death bonebeds. Although Regaliceratops’ social behavior is speculative given the limited fossil record, its display structures might suggest complex social interactions. Regaliceratops likely shared its habitat with other dinosaurs, including the ankylosaur Anodontosaurus and the small predator Atrociraptor.