Heterodontosaurus, meaning “different toothed lizard”, is a genus of dinosaur from the Early Jurassic Period of what is now South Africa. The type species, H. tucki, was found in the Upper Elliot Formation of the Hettangian age (199 to 196 million years ago). Two species are known.
This herbivorous dinosaur ate mostly plants despite having canines. It was a small ornithischian reaching a total length of 3 feet. It had a long, narrow pelvic bone which was like more advanced ornithischians. The hand had an unusual set of five fingers, two of which may have been opposable. This allowed the dinosaur to grasp and manipulate food. The foot and ankle bones were fused like that of modern birds.
The specialized teeth gave rise to its name, Heterodontosaurus. Most reptiles have a single type of tooth in their jaws, while this animal had three. Small teeth were located at the front of the jaws most likely used for chopping leaves and stems. A large pair of tusk-teeth were next in line. The purpose of these teeth is unknown, but speculation leans toward sexual display. The tusk teeth could also have been used as weapons by rival males in dispute of mating rights and territory. The final set of teeth were squared and tall. These teeth were adapted for chewing. It had fleshy cheeks that helped keep food in its mouth while chewing. Based on the teeth alone, scientists have debated over what the Heterodontosaurus ate. Some believe this to be an omnivore, eating both plants and animals.