When a scientist who has been digging for fossils or other remains of ancient life turns up with some teeth, he is very happy. Teeth are an Important clue as to the kind of creature it was that lived there.

For example, beasts of prey have tearing teeth, rodents have gnawing teeth, and cattle have grinding teeth. Every animal—whether horse, cow, mouse, cat, or dog—has teeth suitable for its way of life, its food, and even its general nature.