Yandusaurus

Type Species: Yandusaurus hongheensis

Classification: Dinosauria – Ornithischia – Neornithischia  

Time Period: Middle Jurassic

Location: China 

Diet: Herbivore 

Yandusaurus is known from two nearly complete skeletons. This bipedal, fast-moving ornithischian was larger than its contemporary Agilisaurus. Yandusaurus had large eyes, long legs built for speed, and short forearms with five grasping fingers. Its head was small, and its jaws were filled with chopping, ridged teeth (the Chinese discoverers compared these ridges to the fingers of a Buddha statue). Yandusaurus held food in its cheek pouches while it chewed, much like modern cows and camels. 

Yandusaurus belongs to the neornithischians, a sister clade to the thyreophorans. Neornithischians are distinguished by a thick layer of asymmetrical enamel on the inside of their lower teeth. Their teeth wore unevenly with chewing and developed sharp ridges that allowed them to break down tougher plant food than other herbivorous dinosaurs. Neornithischians include a number of basal herbivores that are historically known as ‘hypsilophodonts,’ though this classification has fallen out of vogue in recent years.