Psittacosaurus (meaning “parrot lizard”) was a small, very primitive ceratopsian. This fast-moving plant-eater had a narrow, horny beak with no teeth, and cheek teeth towards the rear of the mouth. It had a boxy skull with short, horn-like projections on the cheeks. It had four long fingers on each hand; the arms were much shorter than the legs.
The Centrosaurus was a stocky dinosaur with large strong muscles from the late Cretaceous found in Canada. It was not the largest dinosaur of its family (only 20 ft long), and was a lot like the modern Rhinoceros.
The Triceratops, similar to to the modern day Rhino, had three distinctive horns found on its face as well as a large body and a unique frill around its head.