English: Pachyrhinosaurus canadensis is a centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America. Instead of horns, its skull bore massive, flattened bosses - a large boss over the nose and a smaller one over the eyes. A prominent pair of horns grew from the frill and extended upwards. The skull also bore several smaller horns or ornaments that varied between individuals. Size estimates for the largest Pachyrhinosaurus species indicate lengths of 6–8 m and a weight of 3–4 t. Pachyrhinosaurus was herbivorous and possessed strong cheek teeth to help them chew tough, fibrous plants.