Psittacosaurus is a genus of dinosaur belonging to the family Psittacosauridae. It thrived during the Early Cretaceous, approximately 125 to 100 million years ago, in what is now present-day Asia. The first fossils of Psittacosaurus were discovered in the 1920s in Mongolia and China, providing paleontologists with valuable insights into this dinosaur.

Psittacosaurus was one of the earliest ceratopsians, but closer to Triceratops than Yinlong. Psittacosaurus is one of the most completely known dinosaur genera. Fossils of hundreds of individuals have been collected so far, including many complete skeletons. Most age classes are represented, from hatchling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in thefossil record has led to the labelling of Lower Cretaceous sediments of east Asia the Psittacosaurus biochron.

Psittacosaurus was a small to medium-sized dinosaur, measuring about 1 to 2 meters in length. It possessed a robust body with a short tail and stood on stout hind limbs. One of its most distinctive features was its beak-like mouth, resembling that of a parrot. Psittacosaurus had a unique arrangement of sharp teeth in the beak and cheek regions, ideal for processing plant material.

Psittacosaurus likely exhibited both solitary and group behavior, with individuals coming together for social interactions and breeding. Its strong beak and dental adaptations suggest a selective feeding strategy, allowing it to process plant material efficiently. Psittacosaurus may have used its strong hind limbs for quick bursts of speed and its tail for balance during locomotion.