These are fossils of the tail of Psittacosaurus, which is very complete and has very clear bone lines. What's particularly remarkable is its exceptionally beautiful tail. Matrix: 17*11*6 cm. Psittacosaurus is a very early ceratopsaurus dinosaur. They have developed many characteristics on their own, and they also have many of the same physiological and structural features as the later ceratops, such as protoceratops and elephant-sized triceratops.