The structure of the snake. Interesting Snake Facts

Snakes crawl, intensively bending their bodies, and swallow very large prey whole. Both require powerful musculature, and complex bone skeletal reinforcement would only be a hindrance. Therefore, from the point of view of mechanics, snakes are an elastic, durable tube with a minimum number of rigid frame elements. Ho poorly developed skeleton limits the possibility of increasing the size of the body. Mathematical calculations show that with a snake physique, the maximum body length, in principle, cannot exceed 15 m, otherwise such a monster simply could not move on the ground, but was forced to live in water.

Scull
The structure of the skull in snakes is completely unique. It evolved, adapting to a peculiar way of eating. The head of any snake is very small in relation to the size of the prey that the snake is able to swallow whole. This ability is due to the fact that the bones of the facial part of the skull in almost all snakes are movably connected to each other. The lower jaw is attached to the skull by ligaments that can be greatly stretched. In addition, the lower jaw is not continuous, it is connected in the center by an elastic ligament. All this guarantees excellent extensibility of the snake's mouth.
Snakes have well developed teeth, they are located on the upper and lower jaws, and in many species - also on the palatine, pterygoid and premaxillary bones. But since snakes do not chew and do not tear their prey, their teeth are very thin, medium-sized, although sharp. Non-venomous snakes have teeth that are used to push prey towards the esophagus, and poisonous snakes also have special teeth that serve to bite and inject poison into prey; they are bent back. In already-shaped poisonous snakes, the teeth are grooved, located on the back of the upper jaw, equipped with small grooves or open tubules through which the poison flows from the poisonous glands. In aspid and sea snakes, poisonous teeth are tubular, have a closed channel in the cavity, and are fixedly fixed on the jaw in front of the mouth. In vipers and pit vipers, the venomous teeth also have a tubular structure, but they are longer than those of the already shaped ones, and have a very interesting mount. The maxillary bone of these snakes is very short, hinged. Therefore, poisonous teeth have the ability to fold when the snake's mouth is closed, in this case they lie along the jaw with a sharp end back. When the snake opens its mouth, the maxillary bone with the venomous teeth rotates to stand upright, and the teeth are now pointing down and ready to bite.

Front and rear limbs
In the process of evolution, during the transition to a climbing lifestyle, the belt of the forelimbs completely atrophied in snakes. However, in some representatives of the infraorder of lower snakes, small rudiments of the pelvis have been preserved (for example, in boas, narrow-mouthed snakes). In addition, boas and roll snakes have paired claws on the sides of the anus, which are vestiges of the hind limbs inherited from the lizard-like ancestors of snakes.

Spine
Since snakes do not have a girdle of the upper and lower extremities, there is no sternum, the division of the spine into sections, like in other vertebrates, cannot be carried out clearly. The spine of snakes is flexible, long and extremely mobile. It consists of a large number of vertebrae. In thick and short snakes, such as, for example, the Gaboon viper, or gabonika, there are 141 of them. And in the longest and thinnest snakes, the number of vertebrae reaches 435. Due to the absence of the sternum, the ribs are attached very movably, they can diverge widely to the sides so that along the esophagus and large prey could pass through the stomach, they can converge, they can strongly flatten, allowing the snake to flatten the body during defense or, if necessary, penetrate into a narrow, hard-to-reach hole.

Equipped with two equally developed lungs. But vipers and sea snakes have only one lung. Snakes have a relatively small heart, a considerable distance from the head. In asps, for example, it lies at the beginning of the second third of the body. The spinal cord of snakes is voluminous and significantly exceeds the head in its mass. It fills the internal cavity of the spinal column along its entire length.

The bones of the head have a peculiar structure. The bones that form the upper jaw are movably connected to each other and to neighboring bones, and the left and right halves of the lower jaw are fastened with an tensile ligament. This allows snakes to open their mouths wide and swallow rather large prey. The mouth of a gyurza, whose head does not exceed 5-7 cm 2 and can move apart in all directions so much that it is able to swallow a pigeon or a rat.

The teeth of snakes serve mainly to capture and hold the victim, poisonous snakes have two larger teeth - to kill it and protect it at the moment of danger.

Most snakes feed on rodents, birds, and insects. It has been established that snakes that feed on cold-blooded animals (insects, frogs, lizards) take food at least once a week. Snakes that feed on warm-blooded birds, rodents, are able to withstand prolonged starvation. In the favorable months of the year, snakes feed once or twice a day, hunting rodents and birds at night, and insects in the early morning and evening. In captivity, in the presence of water, snakes lie in terrariums without food for several months. Snakes have highly developed muscles. They have as many intercostal muscles as ribs. In addition, muscles attached to the ribs and vertebrae run along the back. This allows the snakes to move vigorously in a wide variety of directions. The muscles of snakes, like those of all reptiles, are pale in color.

An impressive sight is a rattlesnake, the owner of powerful muscles and ligaments, in a menacing pose. Her body resembles in these moments a tight steel spring, ready to unfold with terrible force. The tail end is folded into a spiral ring, in the center of which a ratchet is vertically exposed, making a rather distinct rustle. The middle part of the body is raised at an angle in the form of a high column. A sudden encounter with such a snake is dangerous even for an experienced snake catcher.

Only a few snakes can, like a cobra, raise the front third of the body and very few, like the gigantic anaconda, raise the front half. Not all snakes grabbed by the tail are able to bend in weight so as to bite the hand.

Snakes living on the banks of rivers and lakes, in the seas and oceans, are excellent swimmers. In water, they make the same energetic movements as on land. Snakes are able to quickly climb trees by moving in a spiral around the trunk. Their movements resemble the movement of caterpillars, resting alternately on the front, middle and back of the body. Well climbs and climbs trees, hiding in the foliage, Wagler's tree viper ( Tropidolaemus wagleri) is a native of South America.

It is generally accepted that snakes are not able to make a jump. The exceptions are a few snakes, including the Indian short python and the jumping pit viper, which lives in Central America. This snake, reaching a meter in length, has extremely strong muscles. Relatively short, she appears oversized and oversized. Having gathered the body into a tight spiral, the viper makes a throw over a distance of more than 60 cm. If the viper is on a hillock, stump or on the edge of a ditch, then it is able to jump further. The local population knows how dangerous this poisonous jumper is, which is not easy to spot because of the colorful protective coloration.

A few days before the molt, the snakes become as if blind: the cornea of ​​​​the eyes becomes cloudy and opaque. Snakes do not appear in this state under the rays of the sun due to involuntary "blindness" and in order not to lose the moisture needed to shed the stratum corneum during molting. They usually lie in rock crevices or other hidden places until their sight is restored. At this time, snakes determine the situation with the help of a language that can touch the environment, and rattlesnakes and pythons even hunt using thermolocators.

Before molting, snakes rub their muzzle against the ground until the skin bursts and begins to separate from the front of the head; first, a thin, transparent cuticle on the lips is separated, a large hole is formed. As a result, two blades appear - one on the top of the head, the other on the bottom. They bend back and gradually turn out. In the end, the inner surface is turned outward. To speed up the molt and get rid of the "creep out", the snakes crawl through the narrow cracks between the stones and thorny bushes.

Snakes often shed their horny covering after laying eggs. Younger individuals molt more often than older ones. Pacific rattlesnakes molt 3 to 6 times during their first year of life. As an adult, they molt only once a year and a half. Some large snakes, such as the reticulated python of the Malay Archipelago ( Python reticulatus), shed almost monthly. Desert snakes - only once or twice a year. Shortly after the first spring molt, mating begins in snakes. At this time, snakes gather in groups.

Legends often speak of large balls of several snakes. Superstitious people called such balls "snake eggs" and attributed miraculous powers to them. In fact, during mating, the male and female, tightly wrapped around each other, lie for hours, choosing a shady place for this.

During the mating season, battles take place between male vipers. They raise the front parts of the body vertically and stand in this position, making oscillatory movements, and hiss. Then the snakes begin to collide heads, intertwine, move together for a while and then disperse. As a rule, during the battles, vipers do not bite.

After about four months, the female lays in a warm and damp place from 6 to 40 eggs, and in gigantic snakes - up to 100. Some snakes lay eggs so ripe that the cubs break the egg shells either in the mother's body or immediately after laying. The mother takes care of the cubs, little or no care for them at all. The cubs of some snakes in the first years of life grow quite quickly, then more slowly, and finally, their growth barely noticeably increases during the year, although they continue to grow until the end of their lives.

In Mexico, at the zoo, I saw the offspring of one of the largest vipers on the American continent - bushmaster ( Lachesis muta). This viviparous snake was the mother of fifty cubs. The length of an adult female reached 210 cm, the cubs that had already grown up - 25 cm. Graceful, brightly colored snakes, which were born only yesterday, energetically scurried around the mother. They were so beautiful that they involuntarily wanted to take them in hand. But we were warned that they can bite. Therefore, they were fenced off by a glass wall from zoo visitors.

Snakes rarely breed in captivity. King Cobra ( Ophiophagus hannah) at the Bronx Zoo, located in the suburbs of New York, once laid 41 eggs. This was the second time that a cobra has laid eggs in captivity. The attendant transferred the eggs in the elastic box to the thermostat. The mother cobra, left without eggs, was literally furious with anger and five eggs had to be returned from the incubator to the nest. The next year, all the eggs were left near the cobra: many of them were damaged by the cobra, snakes hatched from the rest.

Snakes, as a rule, quickly get used to captivity. At first, they sometimes refuse to eat. In such cases, live mice should be given, later dead animals and even pieces of meat can be fed. If the snake continues to refuse food, it can be fed by pouring an egg into the stomach through a glass funnel inserted into the esophagus. Snakes gradually get used to the person constantly caring for them, react to the sound of steps and the opening of the cage door, take the offered food from tongs, and allow themselves to be touched. However, it should be remembered that the snake, being an insidious creature, can unexpectedly bite even after being considered “tame” for several months.

For a long time, South American rattlesnakes persist, refusing food. In a number of cases, rats let in to highly poisonous snakes did not make any impression on them. In turn, the rats did not experience the slightest fear of snakes. The noise the rattles made only aroused their curiosity. The rats ran over the bodies of the snakes, jumped on their backs and eventually, to the chagrin of the owner of the snakes, they gnawed one of them. Rattlesnakes sometimes starved in zoos for up to nine months. During a long fast, snakes drank water, bathed, shed their skin, and only after that they suddenly acquired an appetite.

Snakes of various genera, planted in one cage or terrarium, as a rule, get along with each other. You can plant up to a hundred snakes of various species together, attach several vipers to them and observe their complete mutual indifference. But the opposite can happen if a snake is placed with them, the food of which was unknown to the owner of the snakes. Peaceful to harmless in appearance, it can already attack vipers and even cobras, which are not much inferior to it in size. One of our terrariums kept a snake snake and a rather large cobra together. One day the cobra disappeared. Her search was fruitless. The escape of the cobra caused a great stir. Someone accidentally drew attention to the huge thickness of the body of the snake; the mysterious disappearance of the cobra was unraveled: it was swallowed by a snake.

In a terrarium where snakes are kept, there must certainly be a pool of water for swimming, sand, large stones, an electric lamp with a conical lampshade. Cleanliness and systematic exposure to ultraviolet light have a beneficial effect on snakes. It is believed that with good care, snakes can withstand captivity in zoos for 10-12 years.

Literature: E F. F. Talyzin "Poisonous animals of land and sea." Publishing house "Knowledge", Moscow, 1970

The number of vertebrae in snakes of different species depends on their size and varies from 141 to 435. The last vertebrae, from 2 to 10, are caudal; the trunk vertebrae bearing short ribs are not divided into sections.

Some species of snakes do not have a chest, which contributes to the absorption of a large amount of food, and also allows you to get into the most inaccessible places: cracks, cracks.

Reptiles move, relying on the ribs and convex plates located on the belly. There are several ways of moving snakes: lateral undulating, rectilinear, spiral, lateral movement.

With a lateral wave-like movement, the snake describes curves with its body, resembling the shape of the letter S. With a rectilinear, leaning on small plates on the belly, the animal pushes a part of the body forward, and then leans back.

Spiral movement is used when climbing trees: the snake wraps its tail around a tree trunk, throws up the front of the body, clings to a branch, and then pulls up the lower body.

The side move is an alternately alternating movement: pushing the front of the body to the side and pulling the back. An important role in the description of snakes is played by the features of the scaly cover, the number, shape, size and location of the head shields, grouped in the order characteristic of each individual species. It is also necessary to pay attention to the horny scales covering the body of snakes. As a rule, they are diamond-shaped, smooth to the touch, with a longitudinal keel, arranged in a tile-like manner.

Between the scales are areas of skin, collected in small folds. Longitudinal rows of horny scales, when large prey is swallowed by a snake, expand, skin folds straighten out, and the body greatly increases in diameter.

Of no small importance in describing the species is the number of scales around the body, the counting of which is carried out around the middle of the body at an angle. This does not take into account the number of abdominal scutes, starting from the first, elongated, located on the throat, and ending with the anal, lying in front of the cloacal opening. The abdominal shields are connected by soft leathery folds, which straighten out when food is swallowed. The abdominal shields diverge in the longitudinal direction.

The top layer of the skin of healthy snakes exfoliates 2-4 times a year. Molting starts from the front of the head. Trying to get rid of the old skin, the snakes begin to actively move, rub their heads against stones and soil. As a result, the old skin completely comes off the body of the reptile. Sick animals molt more often, while their skin exfoliates in pieces.

The skull of snakes is designed in such a way that when capturing prey, their mouth stretches widely, allowing them to swallow alive an animal that is often thicker than the body of the reptile itself. The anterior part of the skull, to which the lower jaw is attached by elastic ligaments, is equipped with movable, interconnected bones. The brain is enclosed in a bone capsule.

The formation of well-developed, thin, sharp teeth, directed towards the pharynx and serving not for chewing, but for holding prey, pushing it into the esophagus, occurs on the upper and lower jaws, and in some snakes - on the palatine, pterygoid, premaxillary bones. Behind a pair of active teeth are usually spare ones that grow quickly if the working pair breaks.

The tongue is the most important sense organ of snakes. With a forked tip of the tongue, the snake touches nearby objects, receives information about substances contained in the air, moves along the trail of prey, searches for a partner, finds water.

The eyes of snakes are devoid of separate eyelids, covered with a motionless transparent leathery shell, so they seem to be constantly open. The result of this eye structure is a decrease in visual acuity. It is worth noting that during molting, affecting the cornea of ​​the eye, the reptile completely loses the ability to see, but after a few days, vision is restored, since the skin film that has faded along with the cuticle is replaced by a new transparent shell. Diurnal snakes have a round pupil; in twilight and nocturnal snakes, it is elongated into a vertical slit and resembles a cat's.

The representatives of this suborder of reptiles have a well-developed sense of smell. The nostrils, located on the side or upper part of the head, are equipped with closing valves that protect against water when diving, sand when crawling. The nervous system of snakes is represented by a small brain and a long spinal cord, which leads to precise coordination of body movements, sensitivity to soil vibrations, which compensates for the lack of hearing.

The internal organs of snakes (some of them unpaired) are usually elongated and asymmetrically arranged. So, in some species, both lungs are developed, but the right one is larger than the left one; in representatives of other species, the left lung may be absent, which in no way affects the vital activity of snakes. The digestive system, represented by the rectum, is short, the stomach and kidneys are elongated, and the bladder is absent. The testes of males are elongated, the genital organ looks like paired sacs located under the skin behind the anus. The length of the body of snakes is measured from the head to the anterior edge of the opening of the cloaca, the length of the tail - from the anterior edge of the cloaca to the tip of the tail.

Snakes are a very peculiar group of animals with unique anatomical, physiological and behavioral traits. Snakes make up a separate suborder in the Scaly order. At first glance, it is easy to distinguish them from lizards - by the presence or absence of limbs. But in fact, the absence of legs is not the main sign of a snake; there are also legless species of lizards that are difficult to distinguish from snakes. These reptiles have reached a huge diversity - there are 2500 species of snakes in the world!

Common garter snake (Thamnophis sirtalis).

The name snake itself can be understood in two ways: in the broad sense of the word, all legless reptiles are called snakes, but in the scientific community there are groups of snakes with specific names - vipers, cobras, snakes, pythons, boas, muzzles, snakes, asps, etc. Only some of the species retained the scientific name "snake". This article will focus on such snakes in the narrow sense of the word, while other systematic subgroups will be covered separately.

The body of snakes is unusually elongated, its length can exceed the width and height by 10-100 times. Dimensions can vary from 10 cm to 5 m. The very shape of the body is not at all as monotonous as it might seem. In some species, the body can be shortened and thick, as if rolled, in others it is moderately long and wide, in others it is very thin, and in sea snakes it is flattened laterally like a ribbon. The head has a triangular shape, and the bones in the skull of the snake are connected very movably. The ligaments between the upper and lower jaws and ... the left and right halves of each jaw are especially elastic (they are not tightly connected in snakes).

Such a connection allows these reptiles to open their mouths extremely wide and swallow prey many times larger than the snake itself, and during swallowing, the snake alternately moves the right and left halves of the upper jaw and thereby pushes the prey into the throat.

The body of the snake is incredibly flexible, this is facilitated not only by the considerable length of the body, but also by the structure of the skeleton: the number of vertebrae reaches 141-435, and the ribs are connected to the skeleton flexibly. This allows snakes to undulate their body (necessary for movement), coil it into a ball (defensive reaction), and even twist it into knots (needed when attacking). The tail is anatomically weakly separated from the body. Due to the elongated shape of the body, the internal organs are greatly modified: they are all also strongly elongated, the paired organs are located asymmetrically, and in general there is only one lung - the right one. True, primitive species of snakes may also have a left lung, but it is rudimentary (underdeveloped).

The absence of limbs left an imprint not only on movement, but also on the way snakes feed. Well, try to catch prey without hands and eat it! Therefore, the only way to kill the victim for the snake is poison. Snake venom is a highly toxic saliva produced by modified salivary glands. The ducts of these glands do not open directly into the mouth, but into the canal of special poisonous teeth. A snake has only two such teeth, they can be located closer to the edge or in the depths of the mouth (the depth of the bite and, to some extent, the degree of danger of each species depends on this). All species of snakes are poisonous to some extent, but in some species the poison acts mainly on warm-blooded animals (birds, mammals, including humans), while in others it affects cold-blooded animals (amphibians and reptiles). Therefore, the first species are conditionally called poisonous, and the second - non-poisonous. By its action, the poison is hemolytic (causes the destruction of red blood cells, impaired blood clotting) or neurotoxic (affects the nervous system, leads to paralysis, blindness, hallucinations). There are mixed poisons.

The thin whip-like body of the Mexican sharp-headed snake (Oxybelis aeneus) makes it indistinguishable from dry branches.

In the case of a snake bite, it is necessary to squeeze the poison out of the wound (within a minute after the bite), you can also suck and spit the poison, but only if you have no damage in the oral cavity. A couple of minutes after the bite, these measures are no longer effective. In any case, the bitten must be taken to the hospital, the main thing is not to forget in a hurry what the snake looked like. Its species affiliation is extremely important for the appointment of anti-snake serum. On the way, the victim must be provided with complete psychological and physical rest, it is necessary to give a tonic drink (tea). But bandaging a bitten limb is not worth it, this does not prevent the absorption of poison, but can easily lead to toxic tissue damage. Remember, panic and fear are harmful because they increase the heart rate, which means they contribute to the rapid spread of poison in the blood! By the way, not a single species of snake is immune to its own poison, if a snake subcutaneously pricks its own poison, it will die in the same way as its victim.

The warning hiss of a snake.

Snakes have very peculiar sense organs: there are no external ears, so they are practically deaf, but snakes perfectly feel the slightest vibrations of the soil, which is often perceived by observers as the ability to “hear” steps; vision is rather weak, snakes see moving prey best; they have no taste as such at all - snakes do not distinguish the taste of food, and even swallow it whole. But they have a well-developed sense of smell, and olfactory receptors are located not only in the nostrils, but also on the tongue. The tongue itself is arranged in a very peculiar way: it has a forked end and receptors located at different ends perceive odor molecules independently of each other. This allows the snake to very accurately determine the position of the victim by smell, for the same reason snakes constantly stick out their tongues, so they sniff.

Decay's snake (Storeria dekayi) sniffing the air.

In addition, some species of snakes have special pits at the end of the muzzle that work as thermolocators. That is, the snake feels the difference in the temperature of surrounding objects, and feels so accurately that it literally “sees” the world around it as in a thermal imager. Such a unique feeling is associated with hunting warm-blooded animals. You can often hear that the eyes of snakes are devoid of eyelids, so they do not blink. But this is only partly correct. In fact, snakes have eyelids, but they have grown together into a transparent film that covers the eye, so the snake really does not blink. Outside, the body of snakes is covered with scales, the size and shape of which vary in different species. In rattlesnakes, the scales at the end of the tail form a kind of "rattle" that makes a crackling sound when the snake rubs the tip of the tail against the body. This is a defensive reaction aimed at scaring away ungulates that can trample the snake. In addition to "rattles", snakes can hiss, exhaling air with force. However, hissing is the only sound snakes make, otherwise they are voiceless (obviously because they are deaf).

These amazing and unusual animals cause panic and mystical horror in many people. Having reached a species diversity of 2.5 thousand species, acquiring unique hunting methods and developing unusually sensitive sense organs, snakes have taken their place in the hierarchy of all life on the planet. Watching the movement of these reptiles, it may seem that the snake has no skeleton, that it consists of solid muscles. Such smoothness and flexibility of movements can no longer be found in the animal world. But besides the peculiarities of the structure of the skeleton of snakes, they surprise a person with other equally interesting adaptive mechanisms.

Snake or no snake?

It would seem that there is nothing easier than identifying a snake. A long body covered with scales, the absence of legs - this is the appearance of the snake. But a similar external structure is also characteristic of some representatives of the neighboring taxon in the order Scaly - legless lizards. About thirty differences separate these two suborders, but there are exceptions in each of the groups. And only a comprehensive analysis of morphological, anatomical, biochemical, genetic and other features allowed taxonomists to make a clear classification of these amazing scaly creatures.

Where are the legs?

Paleontological finds prove that snakes still had legs in the Cretaceous period. The brightest paleontological skeleton of Eupodophis descouensi, found in Lebanon in 2000, is a very well-preserved snake imprint. Skeleton in a fossil that is over 95 million years old. This ancestor of snakes with pronounced limbs is supposed to have lived in the water.

Among evolutionary scientists, disputes over the primary habitat of the ancestors of modern snakes do not subside. Originally aquatic or secondarily adapted to the aquatic environment? The question is still open and waiting for its Nobel laureate.

Features of the skeleton of modern snakes

The result of a centuries-old evolutionary process turned out to be very fortunate for the snake. The skeleton has become kenitic, which means a movable connection of all bones. In the structure of the skull, this is manifested in the non-fixed connection of the upper and lower jaws. Due to the connection with elastic ligaments, the snake can open its mouth to swallow prey many times its size.

The ribs, which snakes have from 140 to 300, are also elastically attached to the spine, which allows them to move apart and pass large food boluses through the esophagus. At the other end, the ribs are attached to the bristles on the belly by means of a muscular articulation. It is this connection that provides the movement of the snake.

The skeleton has no limbs, only some have vestigial bones that indicate a phylogenetic four-legged ancestor. In pythons and boas, they are visible in the form of so-called spurs.

How to run without legs?

The structure of snakes, the skeleton with its structural features, awarded these reptiles with a very special way of movement, the main role in which belongs to scaly plates. The kinetic connection of the vertebrae, ribs and scales through muscles allows all parts to move separately from each other. This helps the snake to bend in any direction and, as they say, tie a knot.

At the same time, precise coordination ensures translational movement in the horizontal plane. Each shield separately becomes perpendicular to a solid surface and is a support for translational movement by repulsion. Muscular effort and shield after shield move the snake's body forward. Therefore, the snake's legs are its shields.

The only thing Conan Doyle got wrong in his short story "Polished Ribbon" was that his snake couldn't get down the string. She would just fall on the hero, waking him up. The snake needs a solid and porous support to move, which is why it can easily slide on the glass.

The structure of bone tissue

In parallel with the complication of the skeleton itself, changes occurred in the bone tissue of the snake bones. The skeleton had to become stronger. The coarse-fibered inner part of the tubular bones is replaced with fine-fibered tissue over time and acquires a clear zonal structure. To put it simply, the bones grow in length and thickness not at the joints of the bones, as, for example, in mammals, but the growth zone is in the middle of the bones. Such a device makes the bone resistant to high stress, while not increasing the mass at all.

They have teeth

If we consider the skeleton of snakes, the photos will impress with the presence of many teeth. But not everyone knows that snake teeth are not intended for chewing food. With the help of the dental system, the snake grabs, holds and pushes the prey into the digestive tract. The structure of the teeth is also connected with this - they are sharp, thin and curved back. Teeth in snakes can be on the upper and lower jaws, on the palatine and premaxillary bones. And 8% of poisonous individuals in the upper jaw have special furrowed teeth with a channel inside, where the poisonous glands open. In some, these teeth are fixed, while in others, the opposite is true. In vipers, for example, they are found on a short maxillary bone that can rotate.

The heart can be anywhere

Well, not quite. Anywhere, but the structure of the circulatory system of snakes allows the blood pump to change its position. This is due to the peculiarity of snake nutrition, because when a whole unground food bolus passes through the esophagus, there is a need to free the passage, displacing vital organs. Another feature of the structure of snakes is associated with the same reason, this is the reduction of one lung. Most snakes either do not have one lung at all, or it is very small.

Snakes have a very peculiar vision of the world

Just imagine, snakes have poor eyesight, they only see movement. There is no hearing as such, but the inner ear is developed, capable of feeling the slightest vibrations of the soil. The extreme sense of smell, provided by hypersensitive receptors in the nostrils, in the mouth and on the tongue (that's why they stick out their tongue - they sniff like that, and do not try to scare someone at all) helps to navigate in space. And their language is bifurcated for a reason. Receptors on different tips of the tongue autonomously perceive odors. As a result, the snake has twice the information about how the world smells.

You can be sure that before you see a snake, it already knows your weight, smell and what you ate for breakfast.

So, to the question of whether a snake has a skeleton, the answer is unequivocal - yes. Its features are so amazing that bionics have not bypassed them. Carnegie Mellon University engineer Howie Choset's Elizabeth robot for researching and searching for artifacts in the Egyptian pyramids is a prime example.

But not only skeletal features are of interest for bionic parametric synthesis. Thermal imagers, echo sounders and sound detectors are all results taken from the experience of natural modeling of the ubiquitous natural selection.