A turtle’s shell is the first thing you’ll likely notice about these fascinating creatures; that and their notoriously slow speed. But it’s easy to come to incorrect conclusions about a turtle’s anatomy, and their shells are much more than homes to these reptiles.
After all, turtles, tortoises, and snails are the only animals to have shells as bodies. They’ve lived all over the world from Indonesia to Hawaii and have survived almost every climate. Their lifespans often exceed humans’, and the most giant turtles can weigh more than a thousand pounds. Turtles are also among the most primitive reptile species, and their shells are the result of millions of years of evolution. But can they live without them?
In this guide, we answer all those important questions about what happens to turtles without their shells, including when the earliest turtle species first appeared to how to treat a broken shell. There’s a lot to be said about the curious anatomy of a turtle. So keep reading to learn more.
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Why do turtles have shells?
There are several purposes for turtle shells, but to understand these, we first need to know where turtle shells came from. Most turtle shells are coated in tough scales. These are called scutes, and although scientists aren’t sure when they evolved, it is thought they materialized as an extension of their backbones.
A common theory is that the first ancestors of turtles didn’t have shells but their ribs started to broaden as they evolved. Still, some believe this would restrict movement and provide inadequate protection, with other evidence suggesting the two parts that make up a turtle shell evolved separately.
These parts are called the carapace, the top part believed to be the back, and the plastron, the lower shell or belly. Both parts shield the turtle’s organs, but the carapace holds the spinal cord and rib cage while the plastron protects the heart and lungs.
Turtle shells also come in handy when encountering predators. Turtles are common prey of foxes, raccoons, minks, and dogs, but even their strong jaws can’t penetrate the hard exterior of a turtle. In fact, scutes are often as tough as bone, and many turtle species can retreat into their shells, bending their necks and pulling in their heads to hide their bodies entirely. Although, aquatic turtles might dive into water rather than use their shells to hide when escaping their predators’ jaws.
Still, shells don’t only provide protection, but they’re also essential reservoirs for turtles, storing water, minerals, fat, and waste. Most turtles are adapted for a life spent in water, so their shell is also important for their aqua-dynamics. While the rounded shells of land tortoises make it easier for them to hide, the longer shape of sea turtles helps them swim.
Some believe the plastron came first in turtle evolution after archeologists discovered a fossil from 220 million years ago that boasted no carapace. Yet, this is questioned by the scientific community and more specialists agree that the first turtle appeared in the Triassic Period with the two essential parts making up its shell.
Can a turtle feel its shell?
Whether a turtle can feel its shell or not is often tied up with whether they can remove them. Shells are connected to turtles by their spinal columns, and so nerve endings run through the entire surface. This means turtles can feel when their shell comes in contact with anything and they also cannot leave their shell.
Just as humans would feel immense pain if they broke any part of their skeleton, the same goes for turtles. Cracking their shell is like breaking a bone and largely unpleasant for the reptiles, especially due to the large amount of force needed to create a crack. But it is also believed that gently scratching or stroking the shell can be enjoyable for a turtle and is a good way to comfort them.
Can turtles live without their shell?
If it wasn’t clear already, the answer to that all-important question is turtles cannot live without their shells. The shell is an essential part of a turtle’s anatomy and forms its main exoskeleton. There is no other barrier between a turtle’s internal organs and the outside world than their shell, and they would not survive without it.
Every turtle is born with its shell, and unlike other reptiles that shed their skin, a turtle will have one shell that grows with the creature for its whole life. The exoskeleton and endoskeleton, or inner bones, develop in the egg before a turtle hatches. Although turtles have 50 more dermal bones than any other vertebrate, their ribs do not extend to the plastron where the heart and lungs are housed. Instead, they remain integrated with the carapace.
Still, no vertebrate can survive without spinal cords, as they connect the brain to the nerves in the whole body. Turtles are no different.
What if a turtle loses its shell?
Fear not. Turtles cannot accidentally lose or leave their shells by their own doing; they can only tuck their limbs inside. If you think you’ve found an empty turtle shell, it’s likely the turtle is actually curled up inside! Never attempt to pry a shell open as this can cause the turtle pain, and if a turtle is hiding, it’s likely it feels threatened by your presence so give it space.
The only way for a turtle to lose its shell is for it to be forcibly removed by a predator or human. If a turtle was ripped from its shell, it is likely only to survive a short matter of minutes or even seconds, just like a human would not be able to live if their spinal column was invasively removed.
If you’ve noticed a turtle seemingly “shedding,” this isn’t the turtle losing its shell. Rather, the hard scutes are likely preparing for new growth. As a turtle grows, the surface produces larger scutes so that it can expand, which is perfectly normal. However, a peeling shell can also indicate disease. This might be a result of temperature fluctuations, overfeeding, injury or infection, and excessive peeling should always be examined by a veterinarian.
Can a turtle survive a cracked shell?
Despite their hard exterior, turtle shells do break. This could be a result of mishandling, falling, being stepped on, a car accident, or being attacked by a predator. A crack can be devastating for a turtle, but it is not an immediate death sentence.
The two types of shell ailments are depression fractures and missing fragments. A depression fracture occurs down the middle of the carapace, or top shell, and this can damage the spine. Whereas, missing shell fragments could refer to a minor chip or a large fragment breakage as a result of a crack. The latter can be fatal.
If you find a turtle in the wild or your own pet with a crack, getting it to a vet should be your first port of call. Some cracks can be repaired with a bonding material in a veterinarian surgery or with adhesive tape if the fracture is very mildly displaced. A vet can also use a process called bridging that fixes plate-like implants to the shell to help the material back together.
Can turtles regrow their shells?
All these solutions to shell fractures are only possible because of the fantastic ability of turtles to regrow their shells slowly.
Since they’re made of living materials, shells grow throughout a turtle’s life and can slowly repair themselves. In fact, turtles can survive in the wild without veterinary attention if their shell fracture isn’t too severe. However, it can take up to a few years for a shell fracture to fully heal and even the smallest fractures can expose a turtle to deadly infection. Whether you come across an injured turtle in the wild or your pet has a chipped shell, it is best never to leave it untreated.
Still, it is not only injury that causes broken or cracked shells. Unsanitary conditions, poor diet, lack of calcium, and lack of sunlight can all cause ulcers to appear on and around a turtle’s shell. These deadly ulcers, or “shell rot,” can cause shell cracks but also kidney damage, liver disease, and thyroid issues.
The good news is you can treat shell rot in a matter of weeks with antibiotic creams and a change in environment. This will help speed up the natural healing abilities of a turtle’s shell.
What is the difference between turtles and tortoises?
The main difference between turtles and tortoises is that tortoises spend most of their life on land while turtles are adapted for living in water. However, all tortoises are types of turtles and both belong to the order “Testudines” or “Chelonia”, which are reptiles encased in bony shells.
Still, a tortoise is a general name for turtles that spend more time on dry land. Other key differences are that tortoises have more rounded or domed shells and turtles have thinner, more water-dynamic shells. The legs also tell them apart, with tortoises boasting “elephantine” and more club-like legs to help them carry their extra body weight. While turtles’ legs are more like flippers, and they sometimes have webbed feet to help them swim.
How long do turtles live?
Turtles are known to exceed the lives of most pets and sometimes even humans. Some tortoise species have even been known to live for over 100 years. However, most turtles live from 10 to 80 years, with the most common turtle of the northern hemisphere, the “map turtle,” named for its distinct shell markings, usually only living to a maximum age of 25.
Still, some sea turtles and larger land tortoises are among the oldest living creatures on earth. Some can live for over 150 years and it is thought the largest might have a lifespan of 400 to 500 years. The oldest known living animal is a tortoise named Jonathon who is thought to have hatched in 1832, five years before Queen Victoria’s coronation, making him at least 189 years old. His age was estimated from the fact he was “fully mature” when brought to Saint Helena in 1882, where he still resides.
Can a snail live without its shell?
Like turtles, snails cannot live without their shells. Along with tortoises, these three species are the only creatures to rely on their shells for life, storage, and protection. Despite being described as “snails without their shells,” slugs are not snails in a later period of their lives. If snails lose their shells, they will not survive as they are part of the bodies that they are born attached to.