- Where to Find? – Turtles are very adaptive, and hence widely present on every continent, except Antarctica. Southeastern North America and South Asia are the hotspots for a vast majority of turtle species.
- Turtle Costs – $20 – $100
- Yearly Living Expenses for Turtles – $200 and $500
- Friendliest Pet Turtle – Red Eared Sliders
- Are Turtles Poisonous? – No, but certain species of turtles can transmit salmonella
Have you seen a turtle without shell? No!
Ever Wondered What’s Inside A Turtle Shell?
The most fun part of playing with a turtle or a tortoise during all our childhood was the moment we reached out to them, they quickly retracted their head and legs inside their shells.
It was much like the shame plant that shrunk itself the moment someone touched it. This not only made turtles and tortoise a subject of intrigue, but most of us always wondered about their shells and how they came about.
And the same has been the case with the scientific community that has worked extensively studying the shells and how it impacts their lives.
Even though it is quite clear that the shell acts as a mode of protection to these creatures, there are many aspects of a shell that we still don’t know about.
Turtle without shell = massive frog pic.twitter.com/sepYT6GJxh
— rudolf the red nosed coochie (@criebabycancer) June 18, 2021
It is still not clearly known how these creatures developed a shell in their cycle of evolution and have baffled scientists for years now. But one thing is clear that it is the shell of a turtle that helps it survive in the wild.
The world of animals is filled with mysteries that humankind has not been able to solve. There are creatures residing deep in the forests or unreachable depths of the ocean that we still haven’t been able to discover.
There are several species that exhibit properties and characteristics that have continued to baffle us as we don’t know why do it. While we have made amazing progress in discovering the world around us, there is a lot left to be understood.
And the turtles and their shells are one such thing. Considered as one of the least dangerous animals in the world, turtles/tortoises live a long life.
Some large species have been believed to live up to 200 years.
Their slow pace, protective covering, and ability to adapt to the surrounding environment make them great survivors. Even though there are several animals that prey on turtles, they have managed to create amazing surviving strategies and have managed to evolve for over 100 million years on Earth.
Turtles and Their shells
The shells on a turtle’s body are a unique characteristic that sets them apart from the rest of the animal kingdom. It is this unique feature that makes them so recognizable and easy to spot.
Without their shells, turtles that are often considered as one of the least dangerous animals in the world will be left quite vulnerable to attacks and it is believed that turtles will not be able to survive without them.
That said, things were not always the same. While all turtles species are believed to have this shell, they have evolved over a period of time. It has been observed that not all turtles had the shells in the early part of their evolution cycle and this unique feature developed as they evolved that now provides them protection from attacks as well as works as a home for them.
But before we get into the evolution cycle of turtles, let’s first understand the current status of their shells, how different species have different kinds of shells, what are the kind of purposes shells solve for turtles, and why they can’t live without the shells.
Turtle Shells – Explained
In the current state of their evolution, two types of shells are found on a turtle’s back – soft shells and hard shells. While both kinds of quite similar to each other in structure, there are some major differences that set them apart.
The shell structure:
All shells, including the hard shells, cover the entire body of a turtle excluding its mouth and legs.
These shells are made of two components – carapace and plastron. The carapace is the upper part of the shell that covers the back of the turtle, while the plastron is the posterior part of the shell covering the lower part of their bodies.
The carapace is believed to be made of ribs that have come together along with some parts of the backbones. The backbone gets fused with the rest of the backbone, but it can still be distinguished from the rest of their bodies and can be identified if looked closely.
Unlike all other animals, turtles are the only species in the entire animal kingdom whose ribs are fused together to make one big bone. All other animals have separated ribs.
There are as many as 300 species of turtles found in the wild, and all of them have different shell shapes.
While some species possess round shells, some have a more pronounced dome-like structure. Some species also have a flatter shell.
But even though the shell shape is different from the outside, the internal bone structure is pretty much the same in all species.
The two parts of the shell – carapace, and plastron have been extensively studied by scientists. And even though a lot has been discovered and known about carapace, plastron still remains a mystery for scientists.
As is known, the carapace is developed by the coming together of the ribs and the backbone, but plastron has not given away its forming process.
One of the most accepted theories about plastron was given by a French zoologist in the 19th century, who suggested that the plastron is made by the sternum of the turtle. But even that theory hasn’t been proved completely.
The carapace and plastron are the two most important components of the shell. But there is yet another component that is important for the shell.
It is known as the bridge. It connects carapace and plastron to each other, working as an important factor in keeping things together for the turtle.
How the bridge is formed is also an unclear mystery, but it is believed that it is formed by the fusing of the ribs, much like a carapace.
It serves two main roles – one is to protect the turtle on its sides, and second, to keep carapace and plastron together.
Turtles that have hard shells have a component called scutes that is responsible for making the shells hard.
This component is made of keratin, the same component that makes nails. Scutes create a layer that protects the carapace and most turtles lose their scutes over a period of time and grow a new one, just like snakes grow new skin.
Tortoise vs Shredder: who wins?
This works really well as a defense mechanism for the turtles. If a predator attacks a turtle’s shell and bites on its outer part, what gets damaged are the scutes, that turtles can grow again. This helps them protect the carapace, which only develops once in their lifetime.
Are turtle shells bulletproof? Let’s see…
Unlike the hard shells that have a coating made of scutes, softshell turtles have a coating of a leather-like material covering the entire part of the shell.
Although soft shells are not as hard as hard shells, they provide enough protection to turtles. Underneath the leather-like material, there is a hard layer of bones that act as the second line of defense.
Are turtles born with the shells?
The answer is yes!
Turtle shell is an inherent part of the turtle’s body that develops inside the egg itself. And unlike other reptiles that shed their skin, turtles develop this shell only once in their lifetime.
The shells are a combination of ribs and the spine that fuse as they continue to grow. These shells are important for their survival as the remaining body parts are quite soft and vulnerable.
Although they can rebuild the scutes that coat the soft shells in certain turtle species, they cannot regrow a shell on the whole. The process of the growth of turtle shells is pretty intricate. The mother lays the eggs in a state where the turtle development is in an early stage. The embryo then develops a notochord and somites.
These two eventually make the spine. Next, the carapacial ridge is formed inside the egg and the embryo starts resembling a turtle.
For the next some time, the carapace and bones develop. This is followed by the development of the plastron, ribs, and vertebrae.
As the ribs continue to grow, they finally fuse with the spine and create a shell. Finally, the scales on the carapace and plastron appear.
Why is it difficult for turtles to live without shells?
Turtles are vulnerable creatures. They move slowly and have no other form of defense other than the robust turtle shell that they possess right from birth.
This is precisely why shells are extremely important for the survival of sea turtles as well as the tortoise species on the whole. The most important reason why turtles can’t live without their shells is that it is a part of their body.
Did You Know?
The leatherback sea turtles, sometimes called the lute turtle or leathery turtle or simply the luth, is the largest of all living turtles and the heaviest non-crocodilian reptile, reaching lengths of up to 2 metres and weights of 600 kg.
What does a turtle look like without a shell?
The shells are made of their bones (fused ribs and backbone) and are responsible for keeping their bodies together. Inside the shell, turtle bodies are soft and jello-like consistency.
Without the shell, they will be exposed to all kinds of attacks and damages from the surrounding environment.
Can turtles leave their shell?
It is not possible for turtles to lose their shell. Moreover, it is almost impossible for a turtle to survive without its shell.
Turtle and tortoise shells are a part of their body, and are connected through nerves, skin, ribs, and the spinal cord.
It can, though, fracture or break if faced with a strong impact.
They can face two types of fractures – depression fracture and missing shell fragmentation.
In depression fracture, the shell breaks from the middle, causing severe damage to the backbone. Missing shell fragmentation, on the other hand, ranges from a small piece missing from the which doesn’t make much of a difference to a very large piece that could prove to be fatal.
While it is believed that turtle shells heal themselves, it might not always be true in every case.
The evolution of turtles and their shells
Today, it is quite impossible to envision a turtle without a shell. But if theories are to be believed, there was a time in their evolution cycle, when turtles existed without a shell.
There is still very little clarity about turtles developed their shells and how things became the way they are now, there are two major theories that scientists have relied on.
The first theory says that the turtles in their earliest form didn’t have shells, but they did have a protective covering on their back that resembled the scutes of the present-day turtles.
And over the years, these scutes went through different stages of evolution and fused with their bones, and became what they are now.
The other theory states that the ribs of the ancient turtles started extending and broadening and eventually fused with each other.
That resulted in the shell that we see in today’s turtles. After decoding the turtle shells, it is quite obvious that the first theory is more likely to be untrue as the ribs and backbones fuse to make the shell.
Apart from many other studies, scientists released a study in 2016 that suggested that the fossils of the early turtles suggested that they were not living in the water.
Instead, those turtles lived on land and liked to burrow. Their strong rib cage was appropriate for providing protection and stability on land. It also helped them provide more strength for digging.
But larger ribs also meant that they were not able to move fast, something that land animals should have, and thus they were more vulnerable to attacks.
This, changed with time and the ribs started fusing to create the shell. The turtles, after facing more threats on land started spending more time in the water than on land and eventually evolved into the creatures that we know today.
This is only a theory that has been suggested based on different observations.
Turtles are interesting creatures found deep inside the ocean. One of the most intriguing aspects of turtles is their shell that gives them their unique identity.
As important as it is for their protection and survival, equally important it is for their identification. Born with this amazing tool for protection, turtle shells make these slow-moving, gentle creatures a master of the seas.