Snakes are animals with a long, narrow and flexible body. They have no legs, paws, arms, wings or fins. There is only a head, trunk and tail. But does the snake have a skeleton? Let's find out how the body of these reptiles works.
Snake features
Snakes belong to the class of reptiles, squamous order. They live all over the world, except Antarctica, New Zealand, Ireland and some islands of the Pacific Ocean. They also do not occur beyond the Arctic Circle and prefer warm tropics. These animals can live in water, desert, rocky mountains and dense forests.
The body of the 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, outer and middle ear. They hear poorly, but they distinguish vibrations perfectly. Their body is very sensitive to vibrations, and since it is often in direct contact with the ground, animals feel even slight shakes of the earth's crust.
Vision is not well developed in all snakes. It is necessary for them mainly in order to distinguish between movement. The worst see representatives of species living underground. Special thermal receptors help snakes recognize prey. They are located in their front 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, crustaceans. Large snakes can even bite a leopard or wild boar. They, as a rule, swallow the prey whole, pulling on it like a stocking. From the side it may seem that they have absolutely no bones, and the body consists of only muscles.
To understand whether snakes have a skeleton, it is enough to refer to their classification. In biology, they have long been identified as vertebrates, which means that at least this part of the skeleton is present in them. 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 a snake has some similar features, but in many ways differs from other representatives of the class. Unlike amphibians, reptiles have five sections of the spine (cervical, trunk, lumbar, sacral and caudal).
The cervical spine consists of 7-10 movably connected vertebrae, allowing not only to raise and lower, but also to turn the head. The body usually has 16-25 vertebrae; a pair of ribs is attached to each of them. Caudal vertebrae (up to 40) are reduced in size to the tip of the tail.
The skull of reptiles is more ossified and harder than that of amphibians. Its axial and visceral sections in adults grow together. Most representatives have a sternum, a pelvis and two girdles of limbs.
Signature skeleton snake
The main distinguishing feature of snakes is the lack of front and hind limbs. They move, crawling on the ground, completely leaning 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 other snakes, the skeleton consists of a skull, trunk, 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 to each other by ligaments and form a very flexible structure that allows the animal to bend in all directions.
The sternum is completely absent in the skeleton of the snake. From each vertebra from two sides ribs that do not connect together. This allows you to increase the body volume several times when swallowing large food.
The vertebrae and ribs are connected by elastic muscles, with the help of which the snake can even lift the body vertically. In the lower part of the trunk, the ribs are gradually shortened, and in the tail section are absent altogether.
Skull
In all snakes, the bones of the brain box are connected movably. The articulated, arched, and angular bones of the lower jaw fused to each other are connected to the tooth bone by a movable joint. The lower jaw is attached to the upper ligament, which can be greatly stretched to swallow large animals.
For the same purpose, the lower jaw itself consists of two bones, which are connected to each other only by a ligament, but not by a bone. In the process of eating prey, the snake alternately moves the left and right parts, pushing food inward.
The skull of a snake has a unique structure. If the appearance of the spine and ribs is typical of the entire suborder, then the skull reveals the features of a particular type. For example, in a rattlesnake, the skeleton of the head has a triangular shape. In pythons, the head is elongated in an oval shape and slightly flattened, and the bones are much wider than in rattlesnakes.
Teeth
Teeth are also a hallmark of a species or genus. Their shape and quantity depend on the lifestyle of the animal. Snakes do not need them to chew, but to bite, capture and hold prey.
Animals swallow food, but they do not always wait for its death. To prevent the victim from escaping, the teeth in the mouth of the snake are angled and directed inward. Such a mechanism resembles a hook for fishing and allows you to dig deep into the prey.
The teeth of the snake are thin, sharp and are divided into three types: constrictor, or solid, grooved, or grooved, hollow, or tubular. The former are present, as a rule, in non-toxic species. They are short and numerous. On the upper jaw are arranged in two rows, and on the lower - in one.
Grooved teeth are located at the end of the upper jaw. They are longer than solid ones and equipped with a hole through which poison enters. Tubular teeth are very similar to them. They are also needed for injecting poison. They are fixed (with a constant position) or erectile (they are pulled out of the jaw groove in case of danger).
Snake venom
A large number of snakes are poisonous. They need such a dangerous tool not so much for protection as for immobilizing the victim. Usually two long poisonous teeth stand out distinctly in the mouth, but in some species they hide in the depths of the mouth.
The poison is produced by special glands that are located at the temple. Through channels they connect to hollow or embossed teeth and are activated at the right time. Individual representatives of rattlesnakes and vipers can remove their “stings”.
The most dangerous for humans are taipan snakes. They are common in Australia and New Guinea. Before the vaccine was found, mortality from their poison was observed in 90% of cases.