Turtles are reptiles, which are distinguished from other vertebrates by structural features of the skeleton. These unique animals are believed to have lived as far back as 220 million years, making them one of the oldest reptiles, older than lizards, snakes or crocodiles. Modern science knows 327 species of turtles, and many of them are endangered.
Turtle skeleton: structural features
The tortoise skeleton has distinctive features compared to any other vertebrates in which the shoulder blades are located outside the chest, as in humans, big cats, elephants, goats and monkeys. The shelled skeleton of turtles is part of the bone structure. This means that the protective shell is more than just an outer covering. It is an integral part of the animal's body. As the turtle's skeleton begins to form, the shoulder blades and ribs become part of the growing shell. The skeleton is made up of bonesand cartilage.
It is usually divided into 3 main parts:
- skull (cranial box, jaws and sublingual apparatus);
- tortoise axial skeleton, internal or external (shell, vertebrae, ribs and derivatives of ribs);
- appendicular skeleton (limbs, thoracic and pelvic structures).
Tortoise Skeleton: Spine
The skeleton of a land turtle includes the spine along with the cervical, thoracic, lumbar, sacral and caudal regions. The cervical is presented in the form of 8 vertebrae, the first 2 being very mobile. This is followed by 10 trunk vertebrae fused with armored arches. In the region of the sacrum there are flat transverse growths to which the pelvic bones are attached. There are many vertebrae in the tail, usually no more than 33. This section is highly mobile.
The turtle skeleton, the photo of which is presented in the article, includes an almost entirely ossified skull, consisting of a brain and visceral compartment. Teeth as such are absent, in their place are horny plates that form a semblance of a beak. A unique feature of the turtle skeleton compared to other vertebrates is that the limbs are offset under the ribs.
The uniqueness of the structure of sea turtles
The anatomy of the sea turtle is unique in that it is one of the few creatures that has both an internal and an external skeleton. In all species, with the exception of the leathery ones, the externalThe frame provides protection and support for the internal organs. It consists of a bone shell, which, in turn, is divided into two halves: the lower and upper armored plastron. Muscles are attached to the internal skeleton. Like terrestrial turtles, the spine of sea turtles fuses with the shell.
Long fingers in the limbs form flippers that are used to move in the water. They are also used by females to dig holes for eggs during the nesting season. Sea turtles have no teeth in their mouths. Instead, they have a sharp beak with which you can crush food. The leathery mouth contains a number of undeveloped spines.
Not all turtles have hard shells
In leatherback turtles, the spine does not fuse with the shell and does not have a bony shell, instead it is covered with tough skin and supported by a system of tiny bones. These adaptations allow the turtle to dive to a depth of 1.5 km.
Interesting facts about turtles
- A turtle shell is actually made up of approximately 50 different bones. Outwardly, it resembles one solid shield, and its inner shell consists of several bones and is formed by the fusion of the ribs and vertebrae of the animal.
- From the inside, the shell is more like a ribcage that a turtle wears outside of its body. Depending on the species, the size of the animal, as well as other parameters, may differ. For example, the skeleton of the red-eared turtle differs in the length of the limbs and tail, the tail of males is longer and thicker, and the shell is shorter thanin females.
- The animal is forever chained to its house. It is physically unable to leave it, otherwise it will lose its own spine and chest.
- Thanks to the unusually mobile and elastic neck vertebrae, the turtle can pull its head out of the shell or, conversely, hide it when necessary for protection.
- The turtle shell skeleton includes a special movable joint that acts as a hinge and allows the entire body to be pulled in.
- Turtle shells are not armor, although they look like hard and impenetrable shields. There are built-in nerves and blood vessels, so if an animal is injured in its protective shell, it can bleed and feel pain.
- In 1968, two Russian tortoises went into space and returned safe and sound, only losing a little weight. By doing this, they showed that any living being can make a lunar journey.
- Despite their harmless appearance, they can be ruthless predators. A certain type of reptile can grow up to 2.5 meters in length, weigh more than 100 kg and have powerful jaws, a sharply hooked beak, bear claws and a muscular tail. She lures her prey, sometimes even another turtle, by moving her tongue, which looks like a worm.
- An interesting feature of these animals is that in the absence of vocal cords, they can still make sounds. Most of them hiss though you can heara kind of grunting or clucking. The turtle does this by jerking its head sharply in such a way that the air squeezed out of the lungs comes out with a certain sound.
- They turn into real bloodhounds when excited. The reproductive organs of females are hidden in their rectum, in a cavity near the tail, which is used for both reproduction and defecation. The male easily detects the female by the smell of pheromones secreted inside the cloaca.
- Another interesting fact about the turtle butt. It turns out that you can breathe through it! In some species, the rectum is surrounded by a thin membrane through which gas exchange can occur during diving.
- Several species of turtles can live over a hundred years.
- They're not as slow as people think they are. They are mostly herbivores, so they don't have to chase their food. They have nice, thick shells so they don't have to run away from anyone.
