Dinosaurs

About two-thirds of all genera contain dinosaurs that were plant eaters, and a third of the genera include meat-eating dinosaurs. Scientists can determine whether a dinosaur ate meat or plants by looking at its teeth. The teeth of meat-eaters, also known as carnivores (KAR-nih-voars), are pointed for tearing flesh. The teeth of a plant-eater, or herbivore (ER-bih-voar), are flatter for grinding grasses and leaves. Studies of other dinosaur bones can also reveal information about their diet. One study, for instance, showed that some dinosaurs were cannibals. By looking at teeth marks on the bones of certain dinosaurs and comparing the marks to the teeth of the same species, the scientists figured out that the reptile was eating its own kind. This particular species, a theropod called Majungatholus atopus, grew to 29.5 feet (9 meters) long.