Penn researchers determine three dinosaur species are actually one
Psittacosaurus (sih-TACK-oh-sore-us) is a genus of short, beak-faced dinosaurs that lived in Asia 120-125 million years ago, roaming China, Mongolia, Siberia, and possibly Thailand. The plant-eaters lived for about 10 million years in an era after Stegosaurus and before Tyrannosaurus rex, at a time when most dinosaurs were small.