a middle growth stage. The species C. brinkmani, which was described in 2005, was moved to the new genus Coronosaurus in 2012. Description The massive bodies of Centrosaurus were borne by stocky limbs, but they’re not particularly large dinosaurs, reaching in length and in body mass. Like other centrosaurines, Centrosaurus bore single large horns over their noses. These horns curved forwards or backwards depending on the specimen. Skull ornamentation was reduced as animals aged. The frill was relatively short compared to the total skull length, and could grow to over half a meter (68.8 cm) long in the oldest and largest adults. Centrosaurus is distinguished by having two large hornlets which hook forwards over the frill. A pair of small upwards directed horns is also found over the eyes. The frills of Centrosaurus were moderately long, with fairly large fenestrae and small hornlets along the outer edges. Classification The genus Centrosaurus gives its name to the Centrosaurinae subfamily. Its closest relatives appear to be Styracosaurus and Monoclonius. It so closely resembles the latter of these that some paleontologists have considered them to represent the same animal. Other members of the Centrosaurinae clade include Pachyrhinosaurus, Avaceratops, Einiosaurus, Albertaceratops, and Achelousaurus. The cladogram presented below represents a phylogenetic analysis by Chiba et al. (2017): Paleobiology Like other ceratopsids, the jaws of Centrosaurus were adapted to shear through tough plant material. The discovery of gigantic bone beds of Centrosaurus in Canada suggest that they were gregarious animals and could have traveled in large herds. A bone bed composed of Centrosaurus and Styracosaurus remains is known from the Dinosaur Park Formation in what is now Alberta. The mass deaths may have been caused by otherwise non-herding animals gathering around a waterhole during a drought. Centrosaurus is found lower in the formation than Styracosaurus, indicating that Centrosaurus was displaced by Styracosaurus as the environment changed over time. The large frills and nasal horns of the ceratopsians are among the most distinctive facial adornments of all dinosaurs. Their function has been the subject of debate since the first horned dinosaurs were discovered. Common theories concerning the function of ceratopsian frills and horns include defense from predators, combat within the species, and visual display. A 2009 study of Triceratops and Centrosaurus skull lesions found that bone injuries on the skulls were more likely caused by intraspecific combat (horn-to-horn combat) rather than predatory attacks. The frills of Centrosaurus