Skeleton of a turtle: a structure. The structure of the tortoise is terrestrial, red in profile

In the fauna of our planet, reptiles, numbering about 6 thousand species, are represented by several biological groups. One of them is the Turtle squad. Contains 328 species grouped into 14 families. This article will study the structure of the skeleton of a turtle, as well as features related to the water-terrestrial way of life of this animal.

Anatomical structure

Representatives of the detachment live in the steppes, foothills of Pakistan and India, in the deserts of Turkmenistan, Syria and Libya. Like other animals belonging to the family of reptiles, a number of idioadaptations to the dry and hot climate can be found in the structure of their bodies, as well as in the processes of vital activity. Among such adaptations, dense leather covers, absence of mucous glands, presence of horny scales and scutes are distinguished. These formations consist of fibrillar proteins - keratin. Their function is to increase the mechanical strength of the outer covers.

Since the land tortoises, for example, the steppe, the Central Asian, feed on a fairly stiff plant food, they have a beak on their heads - a kind of process that has sharp edges with prongs. They turtles turtles parts of plants and rub them with tuberculate protuberances. On the head are also the eyes. They are limited to three centuries: the lower, upper and third. Presented in the form of a leathery film, covering the eye only half. All turtles have well-developed binocular vision and are perfectly oriented in the environment.

Departments of the skeleton of a turtle

To answer the question of whether there is a skeleton in a turtle, remember that the body of a reptile is divided anatomically into 4 parts. It consists of the head, neck, trunk and tail. Consider the structure of the turtle in a section. So, her spine consists of 5 divisions: cervical, thoracic, lumbar, sacral and caudal. The skeleton of the head is completely bony. It is connected to the neck by means of two movable vertebrae. In all, the tortoise has 8 cervical vertebrae. The head at the moment of danger is drawn into the shell, thanks to the presence of a hole in it. Land reptiles perceive sounds of low frequency. Turtles are referred to as "silent" animals, since their vocal cords are anatomically weakly developed. So they make a hiss or a squeak.

Structure and function of carapace

Continuing to study the skeleton of a turtle, consider the upper part of its shell. It has a bulge that looks like a small bell. In land tortoises, it is particularly tall and massive, while in water it is more flat, streamlined. Carapace consists of two layers. Outer contains keratin scales - scutes, and the lower one completely has a bone structure. It is attached to the arcs of the vertebrae of the lumbar-thoracic region and the ribs. Coloring and drawing of corneal shields of carapace scientists-taxonomists use to determine the species of animals. It was because of the shell that the tortoises were and remain the object of the fishery. From it they make frames for spectacles, cases, knife handles. The shell has several holes in which the animal retracts its head, limbs and tail at the moment of danger.

Plastron and its meaning

The lower part of the shell is called plastron. Between him and the carapace is the soft body of the animal. Both its halves are united by a bone carapace. The plastron itself is an anatomical derivative of the belt of the forelimbs and ribs. He seems to be "soldered" into the body of a turtle. Ground forms have a massive plastron. And in marine life it is reduced to cruciform plates located on the abdominal part of the body. On the shields of the shell, due to the growth, concentric lines are formed. On them, herpetologists can determine the age of the turtle and the state of its health.

Characteristics of the skeleton of the belts of the anterior and posterior extremities of the turtle

The skeleton of a turtle, the scheme of which is shown below, indicates the belonging of animals of this species to reptiles. They have attached to their spine bones of the belt of the forelimbs: scapula, collarbone and crow's formation. They are located in the middle of the chest. The scapula is connected to the carapace by a muscular fold at the location of the first vertebra. The hind limb consists of pubic, iliac and sciatic bones. They form the pelvis. The tail section consists of many small vertebrae, so it is very mobile.

Features of the structure of the extremities of land tortoises

The forelimbs of reptiles consist of the shoulder, forearm, wrist, pastern and finger phalanges, which is similar to the skeleton of other classes of terrestrial vertebrates. However, there are differences in the structure of the bones of the forelimb. For example, the tubular bone of the shoulder is short, and their number, forming the wrist, is less than in mammals. The hind legs also have anatomical features. The femur is very short, and their number in the foot is also reduced. This is especially noticeable in land tortoises: box, red-eared, steppe. Since they move on the surface of the earth, the bones of the phalanges of their fingers experience constant mechanical loads. Thus, the skeleton of a turtle has the necessary idioadaptations, which contribute to its adaptation to the habitat.

Red-bellied turtle: structure and features of vital activity

Among all other species, this animal is most popular as a home inhabitant. The structure of a red-turtled turtle is typical of freshwater forms. Her head is well mobile, the neck is long, the carapace is represented by a carapace of green color, and the plastron is yellow. Because of this, the tortoise is often called the yellowtail. The limbs are massive, covered with horny scutes, ending in claws. In nature, they eat insects that live in abundance along the banks of rivers, larvae and fish fry, and algae. The female is easy to distinguish from the male: it is massive and longer, and its lower jaws are larger. These animals multiply during the period from the end of February to May, laying in the sand pits from 4 to 10 eggs. Little turtles hatch usually in July or August.

Tortoises

This group of reptiles is represented by such animals as the Central Asian turtle, listed in the Red Book, Balkan, Panther. There are only about 40 species. The outer skeleton of a turtle is a shell. It is very massive, with a high raised plastronome. The animals themselves are rather inactive. The Central Asian turtle depends little on water sources. She can for a long time dispense with it, eating juicy leaves or shoots of herbaceous plants. Since the animal has to adapt to the dry climate of the steppe or semi-desert, its annual activity is strictly regulated. It is only 2-3 months, and during the rest of the year the tortoise spends halfheartedly or hibernates in burrows dug in the sand. This happens twice a year - in summer and in winter.

The structure of the tortoise land is characterized by a number of adaptations related to life on land. These pillar-shaped massive limbs, whose phalanges are fully fused, leaving short claws free. The body is covered with horny scales that prevent excessive evaporation and ensure the preservation of water in the tissues of the animal. Thus, animals are reliably protected by a strong bone-horny shell. In addition, they can scare away potential enemies with sharp hissing sounds or a very rapid emptying of a bulk bladder. All species of land tortoises are long-lived. They can live from 50 to 180 years. In addition, they are highly adaptable and resilient.

Nevertheless, let's not forget that 228 species of turtles need protection and are on the verge of extinction. For example, the area of the green turtle is rapidly decreasing. It serves as an object of the fishery, as a person consumes its meat. In connection with urbanization and a decrease in the area of natural habitat, the number of animals is decreasing annually. The question of the expediency of keeping turtles in human dwellings remains disputable, even if they are localized in specially equipped terrarium conditions. A negligible number of these animals live in captivity to their biological age. Most of them die from the ignorant and irresponsible attitude of a person towards them.