Heterodontosaurus, meaning "different toothed lizard", look like ferocious carnivores, but were only the size of a chicken and ate plants with their three different kinds of teeth. They had nipping teeth in the front which they bit against their beak, tusks on the side like a canine that fit into sockets and grinding teeth at the back to chew their food. It is unknown what the tusks were for, but some believe that only the male Heterodontosaurus had them and were maybe used during the mating season to compete against rivals for a mate. From fossils that have been found, tooth wear shows that the Heterodontosaurus could chew from side to side as well as up and down. It looked fierce so it could scare away its predators and if their fierce show didn't scare the enemy away, it could run away quite quickly due to its small size and weight. Its front hands had five fingers all with claws; two of the fingers were tiny and seem to be opposable. Their hind legs, which were larger then its front arms, had three toes that also had claws. The Heterodontosaurus had a long narrow pelvis and a long stiff tail.