10 Surprising Facts About Tortoises and Turtles You Didn't Know

September 11 2026, by Michael van Wassem, 5 min reading time

From a shell that can feel touch to a sex determined by temperature: these are 10 surprising, true facts about tortoises and turtles.

A tortoise or turtle looks like a calm, slow-moving animal, but look closer and you'll find a creature full of surprises: a body plan that has barely changed in tens of millions of years, senses that work differently than you'd think, and a few stubborn myths this article will finally put to rest. Below are ten true facts about tortoises and turtles, from their prehistoric past to their everyday behaviour.

1. Tortoises and turtles walked the earth before most dinosaurs

The turtle lineage goes back roughly 200 to 220 million years, to the Triassic period. That makes tortoises and turtles older than snakes and crocodiles, and means they appeared long before famous dinosaurs such as T. rex ever existed. Their basic design — a sturdy shell, short legs, a horny beak — has worked so well that evolution has changed remarkably little about it since.

2. A tortoise can't crawl out of its shell

A stubborn myth from cartoons: that a tortoise or turtle could swap or leave its shell, the way a hermit crab changes homes. In reality, the shell is fused to the spine and ribs. It isn't a separate "house" at all, but a living part of the skeleton itself that grows along with the animal. A tortoise or turtle without its shell simply couldn't survive.

3. But it can feel you touching its shell

Because the shell is fused to the skeleton, it's full of nerve endings and blood vessels. A tortoise or turtle can feel it perfectly well when you stroke or tap its shell, even though from the outside it looks like a lifeless, hard plate. Some individuals even seem to enjoy a gentle stroke on the shell, while they clearly retreat inside it when handled roughly, as a form of protection.

4. Some turtles can stay underwater for weeks without breathing air

During brumation, some aquatic turtles, such as the North American painted turtle, settle on the bottom of a pond or lake and stay there for weeks to months. They barely breathe air during this time, instead absorbing small amounts of oxygen through their skin and cloaca. That's how they get through the cold months without ever needing to surface.

5. Egg temperature often decides whether it's a male or a female

In many tortoise and turtle species, sex isn't fixed by genetics but determined by the temperature during incubation. In most species, warmer eggs tend to produce more females, cooler eggs more males. That makes these animals especially sensitive to climate shifts, since a nest that's too warm or too cool can skew the male-to-female ratio of an entire generation.

6. They have no teeth, but a razor-sharp beak

Instead of teeth, a tortoise or turtle has a horny beak, similar to a bird's. In some species the edge of that beak is finely serrated, letting them bite effortlessly through plant or animal food. What a tortoise or turtle actually needs varies a lot by species and age: young aquatic turtles naturally eat a lot of animal protein, while tortoises live mainly on fibre-rich plants and weeds. For a suitable supplement, take a look at our fish & turtle food, including sticks and tablets formulated for aquatic turtles.

7. There are around 360 species worldwide

From the tiny Spengler's terrapin to the giant leatherback sea turtle, which can weigh over half a tonne, tortoises and turtles are found on almost every continent, in the sea, in fresh water and on land. Some species spend most of their lives in the ocean and only come ashore to lay eggs, while others never see a drop of water.

8. Some tortoises outlive their owners

With good care, many tortoises, such as the Greek tortoise, can live for several decades — some individuals and species well past 80 years old. That makes a tortoise or turtle anything but a short-term pet: bringing one home usually means planning care for the rest of your own life. A suitable, roomy terrarium that can grow with the animal should be part of that decision from day one.

9. They can go without food for weeks

Tortoises and turtles are cold-blooded, which means their body temperature follows their surroundings and their metabolism runs much slower than a mammal's. As a result, they need relatively little energy and, depending on the species and conditions, can survive weeks or even months without food. That's not a reason to feed one irregularly, though: a consistent feeding routine still matters for healthy growth.

10. Aquatic turtles swim with their eyes wide open

Contrary to what many people think, aquatic turtles don't close their eyes underwater. They have sharp underwater vision, and some species, such as the painted turtle, can even distinguish colours. That helps them spot food, other turtles and danger in time, often in murky water.

💡 Practical tip: a tortoise or turtle kept indoors misses the natural sunlight it needs to produce vitamin D3. Without a good UVB lamp, this can eventually lead to a soft or deformed shell, even if your tortoise or turtle otherwise looks healthy and active.

In short

From a skeleton that existed before the first dinosaurs to a beak with no teeth and a sex determined by temperature: tortoises and turtles keep surprising us, even after staying largely unchanged for millions of years. Thinking about getting a tortoise or turtle yourself, or want to learn more about caring for one? Read our in-depth guide Keeping a Tortoise or Turtle as a Pet: What to Know Before You Start, covering housing, feeding and the legal rules.

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