Tortoises, reptiles of taxonomic order Testudines, are turtles who live on land rather than in the water. In true turtle fashion, tortoises are equipped with tough shells that serve to defend their bodies against outside threats. Just like all turtles, tortoises completely lack teeth.
No Teeth for Tortoises
While they don't have teeth, tortoises' mouths have tough and pointy edges that function pretty effectively for their biting purposes. These mouth edges operate similarly to the bills of birds. River terrapins possess mouth "extras" that the bulk of turtles, including tortoises, don't have. Their top jaws feature tough, bony plates that assist them in grinding their food down, whether mollusks or vegetation. These plates are called secondary palates.
Tortoises and Biting
Don't assume that not having teeth makes tortoises harmless. Many of them can bite with their strong beaks. Red-footed tortoises (Chelonoidis carbonaria), for one, are capable of biting. Male specimens frequently bite females as a technique for wooing them prior to mating. If you ever spot a male red-footed tortoise nipping a female's limb, he's probably attempting to court her for reproduction. Meanwhile, captive tortoises sometimes unintentionally bite their human caretakers -- and the bites can be highly unpleasant. Finger bites from tortoises can sometimes be extremely ouch-inducing, despite their not having teeth. They can draw blood and cause wounds that require medical attention.
Classic Tortoise Diet
Semi-aquatic turtles generally feed on plant and animal matter, equal parts of both. Aquatic turtles generally favor meat. Tortoises stand out in the turtle world in this respect: Plants are basically all they eat. Some common components in the tortoise diet are grasses, herbs, flowers, shrubs, fruit and fungi. While tortoises usually are herbivorous, some of them, including red-footed tortoises, feed on meat, albeit sparingly. Red-footed tortoises occasionally feed on bugs, worms and snails.
No Chewing for Tortoises
Tortoises can initially bite into their food courtesy of their jaws, but chewing is not something they can do. When their food is inside their mouths, they prepare to consume it with their saliva. Their salivary glands assist them in making their food smoother in texture -- and therefore easier to gulp down. They tend to swallow their food in single pieces.
When Tortoises Had Teeth
Although tortoises and turtles of the current day don't have teeth, that wasn't always the case. Many prehistoric specimens indeed had teeth. The extinct Proganochelys quenstedti turtle, for example, was actually thought to possess tiny homodont teeth. These turtles are long extinct; they roamed the planet during the Late Triassic period.
- San Diego Zoo Animals: Turtle & Tortoise
- California Turtle & Tortoise Club: Trivia
- Animal Planet: Turtle
- Encyclopedia of Dinosaurs & Prehistoric Life; Kitty Blount and Maggie Crowley
- Woodland Park Zoo: Red-Footed Tortoise
- Defenders of Wildlife: Basic Facts About Desert Tortoises
- British Chelonia Group: Know Your Tortoise
- Reptiles; Ruth Miller
- Tortoise Group: Desert Tortoise FAQs
- Lafeber Vet: Care of Aquatic & Semi-Aquatic Turtles
- Medioimages/Photodisc/Photodisc/Getty Images