Do Turtles Have Teeth? How Turtle Beaks Do the Job

What a turtle beak is

A turtle’s beak is a sheath of keratin, the tough protein found in fingernails, hair and bird beaks, wrapped around the bones of the upper and lower jaws. Anatomists call it the rhamphotheca. It grows continuously throughout life, so the edges are constantly replaced as they wear down.

Under the beak, the jaw bones are strong and the jaw-closing muscles can be very large, especially in big-headed species. The combination of a sharp edge and strong muscles means turtles can cut, tear and crush food without a single tooth. Turtles also cannot chew as mammals do; they bite off pieces and swallow them, often helped by the tongue and by tearing with the front claws.

Because the beak is part of the skin, it can be colored or patterned like the rest of the head. In many species the edges look pale and almost translucent, and a close look at a turtle’s mouth shows one smooth, continuous cutting edge instead of a row of separate points. That edge is what people sometimes mistake for teeth.

How beaks differ with diet

Turtle beaks are shaped for what each species eats. Comparing them is a little like comparing kitchen tools:

The common snapping turtle has a slicing beak with a strong hook at the tip, used to grab and cut fish, frogs and plants. The alligator snapping turtle has an even more powerful hooked beak that can crack the shells of other turtles and mussels.

The green sea turtle feeds mainly on seagrass and algae as an adult, and its finely serrated lower jaw acts like a saw for cropping plants. Loggerheads have massive heads and broad jaws for crushing crabs, conchs and other hard-shelled prey. More examples are in what do sea turtles eat?.

Spines in the throat are not teeth

The leatherback sea turtle is sometimes said to have teeth in its throat. What it actually has are hundreds of stiff, backward-pointing spines, called papillae, lining the mouth and esophagus. They are made of keratin, not tooth material, and they stop slippery jellyfish from sliding back out while the turtle expels excess seawater.

Many tortoises also have ridges on the roof of the mouth that help grind plant food. These ridges are part of the horny covering of the jaws, not teeth.

The egg tooth of baby turtles

Hatchling turtles have something called an egg tooth: a tiny, sharp point on the tip of the upper beak. They use it to slit the leathery or hard shell of the egg from inside. Despite its name, the turtle egg tooth, known as a caruncle, is not a true tooth. It is a small horny bump that falls off or is absorbed within days to weeks of hatching.

Lizards and snakes, by contrast, have a real tooth for hatching, while turtles, crocodilians and birds use a caruncle.

Did turtles ever have teeth?

Yes, their ancient relatives did. Odontochelys semitestacea, whose name means “toothed turtle with half a shell”, was described from rocks about 220 million years old in Guizhou, China. It had teeth along its upper and lower jaws and a complete lower shell, but no solid upper shell.

Other early turtles, such as Proganochelys from the Late Triassic of Germany, already had toothless jaw edges, probably covered by a beak, but still kept small teeth on the roof of the mouth. Over millions of years these last teeth disappeared, and modern turtles inherited a fully toothless beak.

Living turtles still carry traces of this history in their DNA. Genetic studies have found that genes used to build tooth enamel are broken and no longer work in turtles, a pattern also seen in birds and other toothless animals.

Why a beak works so well for turtles

A beak never needs replacing like a lost tooth, because it keeps growing. It is lighter than a full set of teeth, and its continuous edge suits the way turtles feed: grabbing, cutting and swallowing pieces whole. Birds evolved beaks independently and use them in a similar way.

A toothless mouth can still give a powerful bite. Snapping turtles can produce hundreds of newtons of force with their beaks, enough to cause serious injuries; the numbers are explained in how strong is a snapping turtle bite?. That is one more reason to enjoy turtles from a respectful distance.