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.

A beaver, for example, has great cutting teeth. The canine teeth of dogs and cats are sharp and long so that it is easy for them to seize and hold their prey. Their sharp back teeth cut up and break the flesh and bones.

A squirrel has teeth that can easily gnaw through the hard shell of a nut. Even fish have teeth that help them with their food. Some sharks have cutting teeth for eating fish, while other sharks have blunt teeth for crushing shellfish. The pike has teeth that lean backward as the prey is swallowed and then straighten up again. The teeth of snakes are set inward at an angle so that their prey cannot escape.

Man has what is known as a “collective” dentition, which means that he has many different kinds of teeth, one alongside another.

According to scientists, the structure of the human teeth is evidence that the human body is adapted to a mixed plant-and-animal diet.