Psittacosaurus

Psittacosaurus Temporal range: Lower Cretaceous
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Superorder:	Dinosauria
Order:	Ornithischia
Suborder:	Cerapoda
Infraorder:	Ceratopsia
Family:	Psittacosauridae
Genus:	Psittacosaurus Osborn, 1923
Species
P. mongoliensis (type)      Osborn, 1923 P. sinensis      Young, 1958 P. meileyingensis      Sereno et al., 1988 P. xinjiangensis      Sereno & Zhao, 1988  ?P. sattayaraki      Buffetaut & Suteethorn, 1992 P. neimongoliensis      Russell & Zhao, 1996 P. ordosensis      Russell & Zhao, 1996 P. mazongshanensis      Xu, 1997  ?P. sibiricus      Voronkevich, 1998 P. lujiatunensis      Zhou et al., 2006
Synonyms
Protiguanodon  Osborn, 1923

Psittacosaurus was a small ceratopsian dinosaur from the Lower Cretaceous of what is now Asia, about 130 to 100 million years ago. It was notably more basal than other members of the Ceratopsia: it was bipedal, and had no horns or frill on its head. What made it a ceratopsian was its beak.

It is notable for being the most species-rich dinosaur genus. Nine to eleven species are recognized from fossils found in different regions of China, Mongolia and Russia, with a possible additional species from Thailand.

All species of Psittacosaurus were gazelle-sized bipedal herbivores with a high, powerful beak on the upper jaw. At least one species had long, quill-like structures on its tail and lower back, possibly with a display function. Psittacosaurs were extremely early ceratopsians and, while they developed many novel adaptations of their own, they also shared many features with later ceratopsians, such as Protoceratops and the elephant-sized Triceratops.