What are the differences between turtles and tortoises?
Do turtles and tortoises share any similarities?
People often use the terms “turtle” and “tortoise” interchangeably because of their similar appearance.
However, if you want a turtle or tortoise for a pet, it is essential to know the difference between them.
Turtles and tortoises have different care requirements, especially when it comes to habitat and diet.
There are also many species of both turtles and tortoises, each with its own specialized needs.
This article will take a look at the key differences and similarities between turtles and tortoises, including their anatomy, habitat, diet, behavior, and lifespan.
Similarities & Differences Between Turtles And Tortoises
Generally speaking, turtles tend to live in or near water, while tortoises live on land. Turtles and tortoises have similar shell structures, but their primary differences in appearance are their legs and feet.
All tortoises are turtles, as they belong to the order Testudines, which includes all reptiles having bodies encased in bony shells.
However, not all turtles are tortoises, mainly because turtles are adept at swimming while tortoises cannot swim.
This is due to the differences in their legs and feet, which we will discuss below.
What are the Anatomical Similarities and Differences?
Tortoise legs resemble tiny elephant feet, which are bent instead of being straight and directly below their body.
This helps the tortoise to walk on land, but it does not aid the tortoise in swimming.
Tortoises are generally larger and have heavier shells than turtles, so their elephant-like feet enable them to carry this extra weight on land more easily.
While tortoises may float for short distances until they reach land, they cannot swim and will sink if they do not find land to climb onto.
On the other hand, turtles have webbed feet and long claws, which aid them in swimming and climbing onto steep river banks or logs to bask in the sun.
Some turtles, such as the pig-nosed turtle, even have flippers, allowing them to glide through the water quite easily.
The structural anatomy of turtle and tortoise shells is very similar.
They both have a carapace, the top part of the shell, and a plastron, the bottom half of the shell.
The carapace of both turtles and tortoises is made of bony plates fused and attached to their ribcage and is connected to the plastron through bridges made of bone.
The shells of turtles and tortoises also have similar patterning on their scutes, which are the keratin plates forming the carapace’s outer part.
There are some differences in the shells of turtles in tortoises when it comes to their shape.
Tortoise shells are larger and more dome-shaped than turtle shells, and they also tend to be heavier.
This helps protect them from larger predators they may encounter on land, such as coyotes, foxes, and large birds of prey.
On the other hand, a turtle shell is more flat and streamlined to swim and dive more efficiently.
Some turtle species, such as the leatherback turtle, have only a plastron, with the carapace being a leathery or skin-like membrane not fused to the spine.
This type of shell acts as insulation, allowing the leatherback turtle to dive into deeper, colder waters than other sea turtles.
There are exceptions, such as the pancake tortoise, which has a flattened, flexible shell to hide in narrow cracks between rocks.
Sea turtles cannot tuck themselves into their shell for protection, so they swim sideways to appear larger as a defense.
Another anatomical similarity between turtles and tortoises is they are ectotherms or cold-blooded.
This means they both rely on their external environment to regulate their body temperature.
While they tolerate heat very well, colder temperatures will cause their heartbeat and metabolism to slow down to dangerous levels.