Wannanosaurus

Wannanosaurus is the smallest known ornithischian dinosaur. Its length is estimated at just less than a metre.Estimated from the length of its femur; the skeleton is not complete. It lived in the Upper Cretaceous, about 80 million years ago, and was found in Anhui, China.Hou Lian-Hai 1977. A new primitive Pachycephalosaurian from Anhui, China. Vertebrata PalAsiatica 15: 198–202. 

It is known from a single partial skeleton, including a partial skull roof and lower jaw, an upper leg and lower leg, part of a rib, and other fragments. It was herbivorous, but may also have eaten insects. Wannosaurus means Wanno lizard. It is one of several pachycephalosaurs with flat-topped skulls.

 References 

Category:Pachycephalosauria
Category:Cretaceous dinosaurs