Are Tortoises Reptiles?

Are you a reptile or amphibian lover? Or maybe you just want to learn more about tortoises. Either way, you are probably interested in knowing just what type of animal a tortoise is exactly. Are tortoises reptiles or amphibians? 

All tortoises are reptiles. Tortoises breathe only through their lungs, as opposed to amphibians, which have gills for breathing underwater. Tortoises belong to an order of animals known as Chelonians, a term that encompasses all types and species of tortoises, terrapins, and turtles.

If you want to learn more about tortoises and what makes them reptiles, as well as some characteristics of reptiles in general, then you are in luck. In this article, both the nature of the tortoises’ animal kingdom’s position and that of reptiles as a whole will be explained!

What Makes Tortoises Reptiles?

Tortoises, which is to say, all creatures belonging to the order of turtles known as Testudinidae, are considered reptiles for a few main reasons.

Tortoisos like all reptiles are cold-blooded.

Tortoises are ectothermic creatures, with little to no ability to generate body heat on their own. Tortoises have to find a way to heat themselves up, a process which is necessary for their digestion, as well as for most of their other bodily functions to work normally.

In order to heat themselves up, then, tortoises simply bask in the sunlight, which has UV rays that can quickly and consistently raise their body temperature. While they do need a certain amount of heat in order to live normally, tortoises can suffer from overheating and even die from it. 

In order to help themselves cool down, tortoises (which often live in tropical or desert environments to start with) will often burrow underneath the sand or similar substrate with their legs. Otherwise, they will simply hang out in a particularly shady spot underneath vegetation or rock outcroppings.

When tortoises really need to cool down, they will often just stay still in such a place, presumably so as not to raise their body temperature from the friction that comes with walking all around on the ground.

Tortoises have dry, scaly skin.

In fact, one thing that you may not have known about tortoises is that in spite of looking quite visually similar to turtles, there are no tortoises that swim, even though they may enjoy the occasional puddle. At best, a tortoise in water can float and randomly flail its limbs about in the hopes that it will drift into the shore.

They also are generally unused to humid environments in general, and being too wet for too long can cause a tortoise to become too cold or increase the chances that it becomes ill. However, the occasional soak or rain is good for them, because their skin can become too dry, in addition to their shell drying out too much.

Like Other Most Other Reptiles Tortoises Lay Eggs

The only mammalian exceptions to this rule that I know of are monotremes such as platypuses and some echidnas. Tortoises tend to lay eggs about once a year, although some tortoises lay even more often than this. One species of tropical tortoises, in particular, can lay 6-20 eggs a month for 7 months out of the year. 

Eggs are laid whether or not they are fertilized, something which is similar to how chickens lay eggs, but of course only when the female laying the eggs has mated will the eggs eventually yield cute little baby tortoises. Interestingly, tortoises can carry around incubated eggs for four years before laying them!

When a tortoise goes to lay eggs, it will look for a sloped area to lay them in so that the nest does not get flooded by the rain. They also prefer for the slope to face the sun so that they can be warm while they lay. The soil is usually pretty soft. Once a mother tortoise finds the right spot for a nest, it will begin to dig with its hind legs.

This process can take several hours, and afterward, there will be two piles of dirt next to the new nest. Once the hole is almost about the length of the mother tortoise, she will begin laying, pushing out each egg one by one and gently rolling them out of the way of the next one so as not to damage any of them.

Once the process of laying eggs is complete, the tortoise will use its legs to cover the entrance to the nest with the dirt it previously excavated, camouflaging it and ensuring that its temperature will remain constant so that the eggs will be properly incubated.

If a tortoise never finds an acceptable spot to make a nest and thus never begins the laying process, then it may simply keep the eggs inside, which can be hugely detrimental to its health, sadly.

Like All Reptiles Tortoises Breath Through Thier Lungs 

In fact, in a process markedly different from how humans and most other mammals breathe, by contracting our rib cage and thorax (and thus our lungs) in and out, tortoises use muscles wrapped around their lungs to contract and expand them; these muscles have been referred to as a “sling” of muscles. (Source)

This is an evolutionary feature developed as a result of the degree to which their shells restricted the movement of their ribcage, and eventually, became integrated with their ribcage.

Reptiles Have Backbones 

And no, I’m not talking about the moral kind. Reptiles have actual backbones, and the tortoise is no exception, although a tortoise’s backbone is incorporated into its domed shell. It is fused with it, which makes them quite tough and protects them from certain kinds of damage, but makes them rather inflexible.

Speaking of shells, all tortoises have high domed shells, with the one outlier of this observation being the pancake tortoise. The humble tortoise and its close relative the turtle are the only reptiles with shells. 

Characteristics of Reptiles

There are a few general rules as to what makes a reptile. While there exists the occasional outlier or exception to each of these rules (as is often the case when discussing animals and nature; the earth and its creatures are always surprising us), in most cases a reptile will fit all or most of these descriptions.

  • Reptiles are vertebrates, meaning that they possess backbones.
  • Their bodies are completely covered in scales (or scaly skin, such as in the case of tortoises and turtles).
  • Reptiles are cold-blooded, with a few very obscure noted exceptions.
  • Reptiles either lay eggs or give birth to live young.
  • The eggs of reptiles are fertilized internally, as opposed to say, seahorses, which have eggs that are fertilized individually outside of the body.
  • Reptiles possess at least one lung: in other words, they breathe air and not water. 

Are Tortoises Dinosaurs?

It has often been said in books about dinosaurs that the chicken is the closest living relative to dinosaurs in existence. While this may be true, and the birds today did all descend from dinosaurs, it still depends on who you ask whether or not birds can be fully considered “dinosaurs”. Many emphatically say yes, and the voices saying so have increased in intensity in recent years. 

In a similar fashion, tortoises may not technically be “dinosaurs”, but they do potentially share a common ancestor with them and share some genetic makeup with them, something of which our knowledge has increased significantly over the past decade!

However, since they do not descend purely from dinosaurs as birds do, they definitely cannot be called dinosaurs in a scientific way, even though, unlike modern birds, they predate dinosaurs by several million years.

Tortoises (or at least their ancestors) appeared as early as 250 million years ago, during the Permian period, and Dinosaurs came about as early as 243 million years ago, during the Triassic period.

Tortoises Predate Dinosaurs 

This means that although tortoises came much earlier than dinosaurs, they coexisted with them for millions of years, and survived the extinction events that spelled out the end of dinosaurs, or at dinosaurs as we think of them.

Does the earlier arrival of tortoises onto the world scene preclude any relationship between them and dinosaurs though? As a matter of fact, it doesn’t, as recent scientific research has placed the tortoise in the same group as both modern birds and their dinosaur ancestors: the Archelosauria clade. (Source)

A clade is a natural group of species that, to put it most simply, evolved from one common ancient ancestor. This means that while tortoises are not dinosaurs, they are the distant “cousin” of dinosaurs, and somewhere far back in ancient history is a creature or group of creatures that led to the creation of all three of these significantly unique groups.

Another reason tortoises and their ancestors can’t properly be considered dinosaurs is that they lack structural holes on the side of their skulls. 

This is not the only thing that sets the two animal groups apart, however. Some of the other key differences between tortoises and dinosaurs also include:

  • Dinosaurs were likely warm-blooded, while tortoises and the other anapsids of ancient times were cold-blooded.
  • Many Believe dinosaurs were likely covered with feathers, while tortoises have never had feathers and have always been somewhat scaly.
  • Dinosaurs had fast metabolic rates and were relatively short-lived compared to tortoises, which have slow metabolic rates. Even today, some species of tortoises can live to be over 100 years old. The oldest tortoise alive right now, Jonathan, is 190 years old.

Are Turtles Reptiles?

Turtles, like tortoises, are also reptiles. While they spend incredibly long amounts of time underwater compared to most mammals and can hold their breath for a whole hour, turtles still need to breathe air from time to time. Interestingly enough, some turtles can “breathe” through their cloaca in a process called cloacal respiration.

This is limited only to some snapping turtles though. Turtles are also similar to tortoises in that they have spines that are fused into their shell. And, they also are cold-blooded and bask on warm rocks in order to raise their body temperature.

Something incredible that both tortoises and turtles can do that is related to their slow metabolisms (a consequence, largely, of being cold-blooded), is that they can hibernate (or more correctly, “brumate” during the winter months of the year).

During this time period, they go dormant and don’t need to eat food. When they brumate, tortoises and turtles usually create a burrow in the ground in which to stay nice and warm and cozy.

Turtles are sometimes mistaken for amphibians, due to the amount of time most species of turtles spend in and around water, but they are solidly reptiles, even though they differ from tortoises in regard to their ability to swim.

Differences Between Turtles and Tortoises

Although both turtles and tortoises are Chelonians and Testudines (and have shells with a separate carapace, or top piece, and a lower piece called a plastron), they are placed in separate classification families. Some of the major differences between tortoises and turtles include:

  • Tortoises are terrestrial whereas most turtles spend time in and around aquatic environments.
  • Typically tortoises have a longer life span than turtles, even though turtles live decently long compared to many other animals.
  • Tortoises typically have rounded shells, shaped like a geodesic dome almost, whereas turtles have thinner shells that make them more aerodynamic in the water. 
  • Turtles have more webbed and flipper-like feet, which are, you guessed it, better for swimming.
  • There are several species of softshell turtles, but there is only one kind of softshell tortoise, namely, the pancake tortoise.

Overall, all tortoises are reptiles just like turtles. 

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