Psittacosaurus was an early ceratopsian from Asia between 123 to 100 million years ago in the early Cretaceous. They were bipedal and lacked horns; their head had a very powerful parrot-like beak. At least one species is known to have a crest of quill-like fibers along its tail.
There were many species of Psittacosaurus, the largest were about 2 meters long and 20 kg in mass. They tended to be very common in the times and places where they are found. At least some species tended to live around lakes and may have been good swimmers.