Pachyrhinosaurus

Pachyrhinosaurus is a genus of ceratopsid dinosaur from the Late Cretaceous of western North America.

Pachyrhinosaurus is a genus of ceratopsid dinosaur from the Late Cretaceous of western North America. It is known for the large bony boss on its nose rather than a prominent nose horn, along with a frilled skull and other ornamental horns. Fossils have been found mainly in Alberta, Canada, and Alaska, United States.

Description

Pachyrhinosaurus was a large, quadrupedal herbivorous dinosaur. It had a parrot-like beak and cheek teeth for processing vegetation, and a frilled skull. Its most distinctive feature was a flattened bony boss over the nose, supplemented by other skull ornaments.

Discovery and species

The genus includes three named species: P. canadensis, P. lakustai, and P. perotorum. Fossils have been discovered in Late Cretaceous formations in Canada (especially Alberta) and Alaska, with the northernmost species found in Alaska.

Classification

Pachyrhinosaurus belongs to the ceratopsids, a group of horned dinosaurs, and more specifically to the centrosaurine branch. It is closely related to other frilled horned dinosaurs such as Triceratops, though it had a different skull structure.

Palaeoecology

Evidence places Pachyrhinosaurus in western North American environments near the end of the Cretaceous. It likely fed on tough vegetation and lived in ecosystems that included forests, floodplains, and coastal or lowland settings.