Pachyrhinosaurus is a ceratopsid ceratopsian marginocephalian dinosaur from the Late Cretaceous of Canada and the United States of America. It was named in 1950 by Charles Mortram Sternberg. It was one of the most speciose ceratopsians, with 3 species being known from North America.
Physiology[]
Pachyrhinosaurus was a unique dinosaur. It had the standard ceratopsid body plan, with a bulky body, 4 erect legs, a moderately short tail held low to the ground, a large head with a beaked mouth, and a shield-like, bony frill right on the back of its head; however, instead of having a conical horn on its nose (like other ceratopsians did), it had thick, flattened bosses over its head, with a bigger one on its nose and two smaller ones over its eyes. Its body would have been covered in scaly skin.
Diet[]
Pachyrhinosaurus was an herbivore, feeding on plants low to the ground. Its pointed beak was used to grab pieces of vegetation and pluck them, while the many teeth in the back of its mouth would process the vegetation.
Ecology[]
The use of the large, round, bony bosses on Pachyrhinosaurus has been open to debate for some time, with some scientists suggesting that adults used them for intra-specific head-butting contests. However, due to lack of evidence of damage on the ceratopsids' skulls, it may seem more likely that they were for display; however, many individuals have been found with fractured ribs, which may be evidence of the dinosaurs participating in flank-butting contests instead. Due to a large bonebed containing many individuals, we can assume that Pachyrhinosaurus lived in herds; even if the bone bed only proves that they died in a large group, the most probable cause of death was attempting to cross a flooded river and subsequently getting killed by large debris or simply the inability to swim properly, and this does nothing to prove that they were not social, potentially proving the opposite in reality. Such a possible herding behavior may have been useful, as they would be able to protect themselves from predatory theropods like Albertosaurus in this manner.
In popular culture[]
Pachyrhinosaurus was first introduced to the public through the 2000 Disney movie, Dinosaur, where it is the main ceratopsid featured. Since then, it has been featured in many major pieces of media, such as The Land Before Time, March of the Dinosaurs, and Walking with Dinosaurs 3D, the latter two of which feature it in a semi-accurate light. It was even planned to be in Jurassic World: Fallen Kingdom; however, due to public outcry on how the Jurassic World design bore no resemblance to the real dinosaur, it got a last-minute name-change to Sinoceratops.