An herbivore is an animal that eats plant materials such as leaves, grass, berries, nuts, or roots. Because their food is often course and bulky, their digestive anatomy and physiology is different from that of carnivores. The digestion of plant material starts in the mouth with an enzyme called ptyalin, which is found in the saliva. The food must be chewed well and thoroughly mixed with ptyalin to be broken down adequately. For this reason, herbivores have special molars and a slight side-to-side motion in their jaws when they chew to grind their food. This is in opposition to the exclusively up-and-down motion of carnivores. Herbivores typically lack claws or sharp teeth, although their incisors may be modified into ornaments or fighting tools. Because they eat food that takes a long time to digest, their digestive systems are much longer than in the carnivores. In fact, the intestines can stretch to ten times the length of the body.
One specialized and diverse group of herbivores is the ungulates. For more information about ungulates, click here.
