Snakes: a skeleton of a reptile with signatures and a photo

Snakes are animals with a long, narrow and flexible body. They do not have legs, paws, hands, wings or fins. There is only a head, a trunk and a tail. But does the snake have a skeleton? Let's find out how the body of these reptiles is arranged.

Features of snakes

Snakes belong to a class of reptiles, a group of scaly ones. They live on all the earth, except for Antarctica, New Zealand, Ireland and some islands of the Pacific Ocean. They do not also meet behind the Arctic Circle and prefer the warmer tropics. These animals can live in water, desert, in rocky mountains and dense forests.

The body of snakes is elongated and depending on the species has a length of several centimeters to 7-8 meters. Their skin is covered with scales, the shape and location of which is not the same and is a species trait.

They have no moving eyelids, the outer and middle ear. They hear badly, but they perfectly distinguish vibrations. Their body is very sensitive to fluctuations, and since it is often in direct contact with the ground, the animals feel even minor shakes of the earth's crust.

Vision is well developed not all snakes. It is necessary for them mainly in order to distinguish between motion. The worst is seen by representatives of species living underground. The special receptors of thermal vision help recognize the prey. They are located in their facial part under the eyes (in pythons, vipers) or under the nostrils.

Does the snake have a skeleton?

Snakes are predators. Their food is very diverse: small rodents, birds, eggs, insects, amphibians, fish, crayfish. Large snakes can even eat a leopard or a wild boar. As a rule, they swallow up the extraction as a whole, stretching on it like a stocking. From the side it may seem that they have absolutely no bones, and the body consists of the same muscles.

To understand whether a snake has a skeleton, it is sufficient to turn to their classification. In biology, they have long been identified with vertebrates, which means that at least this part of the skeleton is present. Together with lizards, iguanas, turtles, crocodiles, they belong to reptiles (reptiles), occupying an intermediate link between amphibians and birds.

The structure of the skeleton of the snake has some similar features, but in many respects differs from other representatives of the class. Unlike amphibians, reptiles have five departments of the spine (cervical, trunk, lumbar, sacral and caudal).

The cervical region consists of 7-10 vertically connected vertebrae, allowing not only to raise and lower, but also to turn the head. The trunk usually has 16-25 vertebrae, and a pair of ribs are attached to each of them. Caudal vertebrae (up to 40) decrease in size to the tip of the tail.

The skull of reptiles is more ossified and harder than in amphibians. Its axial and visceral divisions in adult individuals grow together. Most representatives have a sternum, a pelvis and two belts of extremities.

Skeleton of a snake with signatures

The main distinguishing feature of snakes is the absence of front and rear extremities. They move, crawling on the ground, completely resting on the whole body. Rudiments of limbs in the form of small processes are present in the structure of some species, for example, pythons and boas.

In the remaining snakes, the skeleton consists of a skull, a trunk, a tail and ribs. The trunk section is very elongated and contains much more "details" than other reptiles. So, they have from 140 to 450 vertebrae. They are connected with each other by bundles and form a very flexible structure, which allows the animal to bend in all directions.

In the skeleton of the snake is completely missing sternum. From each vertebrae, the ribs on both sides depart, which do not connect with each other. This allows several times to increase the volume of the body when ingesting large meals.

The vertebrae and ribs are joined by elastic muscles, through which the snake can even lift the body vertically. In the lower part of the trunk region, the ribs gradually shorten, and in the tail section are absent altogether.

Skull

In all snakes, the bones of the brain box are connected together. The articular, supra-angular and angular bones of the lower jaw are fused with each other, connected to the dental bone by a movable joint. The lower jaw is attached to the upper ligament, which can be stretched to swallow large animals.

For the same purpose, the lower jaw itself consists of two bones that are joined together only by a bunch, but not by a bone. In the process of eating prey, the snake alternately moves the left and right parts, pushing food inside.

The skull of a snake has a unique structure. If the appearance of the spine and ribs is typical for the entire suborder, the skull reveals the characteristics of a particular species. For example, in a rattlesnake, the skeleton of the head is triangular in shape. In pythons, the head is elongated in the shape of an oval and slightly flattened, and the bones are much wider than in a rattler.

Teeth

Teeth are also a distinguishing feature of a species or genus. Their shape and quantity depend on the animal's way of life. Snakes do not need them to chew, but to bite, capture and hold prey.

Food animals swallow, while not always waiting for her death. To prevent the victim from breaking free, the teeth in the jaws of the snake are at an angle and directed inward. Such a mechanism resembles a hook for catching fish and makes it possible to dig deep into the prey.

Teeth snakes thin, sharp and divided into three types: constrictor, or solid, grooved, or grooved, hollow, or tubular. The former are present, as a rule, in non-poisonous species. They are short and numerous. On the upper jaw are arranged in two rows, and on the bottom - in one row.

Borate teeth are located at the end of the upper jaw. They are longer than solid and are provided with a hole through which the poison enters. They have very similar tubular teeth. They are also needed for injecting poison. They can be fixed (with a constant position) or erectile (protruding from the jaw groove in case of danger).

Venom snake

A large number of snakes are poisonous. Such a dangerous tool they need not so much to protect as to immobilize the victim. Usually two long poisonous teeth are distinctly prominent in the mouth, but in some species they hide in the depth of the mouth.

The poison is produced by special glands that are located at the temple. Through the channels they connect with hollow or relief teeth and are activated at the right time. Some of the representatives of rattles and vipers can clean their "stings".

The most dangerous for humans are snakes of the Taipan family. They are common in Australia and New Guinea. Before the vaccine was found, mortality from their poison was noted in 90% of cases.