Animal teeth

All animals need to eat, but their diets vary a great deal. Some animals, like cows, feed on plants only — they are herbivores. Others, like lions, feed only on other animals — they are carnivores. Then there’s bears and other animals that feed on both plants and animals — these are omnivores. Let’s see how these different diets affect one particular part of their bodies — their teeth.

This cow is a herbivore — it spends its days grazing on grass. Grass, like other plants, is chewy and quite difficult to digest. So the cow spends a long time just chewing the grass, to break it down into smaller pieces, which will be more easily digested. To help them grind grass, cows have well-adapted teeth at the back of their mouths, called molars. Molars are broad and flat, and their surface can be wavy.

When chewing, molars grind and crush grass, almost like millstones grinding wheat to make flour! At the front of their lower jaw, cows have teeth with a sharp edge: incisors. Incisors are adapted for cutting, for example, the grass on the cow’s initial bite. Incisors are usually present on both the lower and the upper jaw. But cows don’t have incisors on their upper jaw!

In their place, they have a hard upper palate, which helps them rip up grass. Rabbits, on the other hand, do have incisors on both the lower and the upper jaws. And because the plants they eat are often quite harsh on the teeth, rabbit teeth grow continuously throughout their life. This is to prevent rabbits from ever being toothless. As for carnivores, they usually have some molars at the back of their mouth, as well as some incisors.

But carnivores are famous for their ferocious canines. Canines are long, sharp teeth — very well adapted to ripping, tearing or cutting flesh. Herbivores don’t have them, because they don’t need them! Carnivores normally have four canines, two on the upper jaw, and two on the lower jaw. Some animals have specially adapted canines.

Some snakes, for example, have needle-like canines, often called fangs, connected to venom glands. When snakes strike their prey, venom is injected through the fangs, almost as if they were syringes. This great white shark is another example of a carnivore with highly specialised teeth. It has a mouth full of pointed, triangular teeth. These are perfect for feeding on large prey, such as sea lions and dolphins.

Not only that, the great white shark has several rows of teeth that are ready to replace any teeth that break off. Finally, there are omnivores, animals that consume a variety of foods. To suit their diverse diets, omnivores have different sets of teeth. Bears have large fangs for eating prey. But they also have large, flat molars for chewing plants and nuts.

Rats, on the other hand, have molars and long incisors that they use to nibble on fruit, meat or other scraps. But they don't have canines, because no part of their diet requires it. Not all animals have teeth, but for those that do, their diet plays an important part in determining which teeth and how many of them they have. Herbivores need large molars to be able to grind difficult-to-chew plants. Carnivores need canines to tear through the meat of their prey.

And omnivores need different types of teeth, depending on what their diet includes. Based on their teeth, which groups of animals do you think cats, dogs and hamsters belong to?