Psittacosaurus

From Freepedia

Psittacosaurus was a parrot dinosaur who lived in Asia in the Late Cretaceous. It grew up to 2.5 metres long and had the squared-shaped skull and parrot-like beak typical of its family. On the sides of it head were a pair of hornlike bumps.

Source: Fantastic Facts About Dinosaurs (ISBN 0-75253-166-2)