Ceratopsians

Ceratopsians were plant-eaters with a narrow, parrot-like beak and a bony frill at the back of the skull. Later ones such as Triceratops, Styracosaurus and Centrosaurus added horns over the eyes or on the nose, and the biggest grew as large as an elephant.

The group began with small, two-legged animals such as Yinlong and Psittacosaurus in Asia. Most of the large horned ceratopsids lived in western North America in the Late Cretaceous, with rows of teeth packed together for slicing tough plants.