Modern reptiles. Class reptiles

Reptiles are called such living creatures as snakes, lizards, hatterias, turtles and crocodiles. Reptiles are both without legs and with legs. They crawl and crawl. Therefore, these reptiles are called reptiles. Also, they have another name. Reptiles are cold-blooded. Cold-blooded, reptiles are called because they really have cold blood. The body temperature of reptiles is completely dependent on temperature. environment, . Since the body of cold-blooded animals does not produce its own heat, therefore, absolutely all reptiles love external heat, and often bask by occupying some hills: stones, snags, bumps, stumps, etc. But if it gets very hot, then the reptiles try to hide in the shade. Thus, they regulate their body temperature.

Where do reptiles live

The habitats of reptiles are very diverse. They live in deserts, steppes and. They can be found both on land and underground, both on water and under water. In general, cold-blooded live almost everywhere, except in places where it is very cold. On the Extreme, you are unlikely to find reptiles.

How do reptiles hibernate

In winter, reptiles hide underground, occupying abandoned burrows, or under driftwood. Then they fall into a kind of hibernation. Their internal processes slow down so much that these cold-blooded creatures can go for several months without any food.

How reptiles reproduce

Reptiles reproduce in exactly the same way, that is, they lay eggs. The only difference is that they do not incubate eggs. They try to bury them in secluded places, covering them with sand, earth, foliage, etc. And after they hatch, the reptiles do not feed the cubs, leaving them to themselves. Whoever survives will survive.

What features do reptiles have

The bodies of reptiles, like fish, are covered with scales. But, again, unlike those who wear their scales throughout their lives, cold-blooded ones change it several times during their existence. Reptiles shed their scales along with their skin. True, not all reptiles do this. For example, turtles and do not shed their skin. Yes, turtles and crocodiles also have parental affection.

Scales on the skin of a lizard

The girdle of the forelimbs is similar to the girdle of amphibians, differing only in a stronger development of ossification. The forelimb of reptiles consists of the upper arm, forearm, and hand. Back - from the thigh, lower leg and foot. Claws are located on the phalanges of the limbs.

Muscular system

The brain is located inside the skull. Row important features distinguishes the brain of reptiles from the brain of amphibians. Often they talk about the so-called sauropsid type of brain, which is also inherent in birds, in contrast to the ichthyopsid type in fish and amphibians.

There are five sections of the reptile brain.

• The forebrain consists of two cerebral hemispheres, from which the olfactory lobes depart. The surface of the cerebral hemispheres is absolutely smooth. In the cerebral vault of the hemispheres, the primary vault is distinguished - the archipallium, which occupies most of the roof of the hemispheres, and the beginnings of the neopallium. The floor of the forebrain mainly consists of the striatum.
• The diencephalon is located between the forebrain and midbrain. The parietal organ is located in its upper part, and the pituitary gland is located on the lower side. The bottom of the diencephalon is occupied by the optic nerves and their decussation (chiasm).
• The midbrain is represented by two large anterior hills - visual lobes, as well as small posterior hills. The visual cortex is more developed than in amphibians.
• The cerebellum covers the anterior part of the medulla oblongata. It is larger compared to the amphibian cerebellum.
• The medulla oblongata forms a bend in the vertical plane, which is characteristic of all amniotes.

12 pairs of cranial nerves leave the brain. In the spinal cord, the division into white and gray matter is more distinct than in amphibians. Segmental spinal nerves depart from the spinal cord, forming a typical brachial and pelvic plexus. The autonomic nervous system (sympathetic and parasympathetic) is clearly expressed in the form of a chain of paired nerve ganglia.

sense organs

Reptiles have five main sense organs:

• The organ of vision - the eyes, are more complex than frogs: in the sclera there is a ring of thin bone plates; an outgrowth departs from the back wall of the eyeball - a scallop that protrudes into the vitreous body; in the ciliary body, striated muscles are developed, which allows not only to move the lens, but also to change its shape, thus focusing in the process of accommodation. The organs of vision have adaptations to work in the air. The lacrimal glands keep the eye from drying out. The outer eyelids and nictitating membrane perform a protective function. In snakes and some lizards, the eyelids fuse together to form a transparent membrane. The retina of the eye can contain both rods and cones. Nocturnal species lack cones. In most diurnal species, the range of color vision is shifted to the yellow-orange part of the spectrum. Vision is crucial among the sense organs of reptiles.
• The olfactory organ is represented by internal nostrils - choanas and vomeronasal organ. Compared to the structure of amphibians, the choanae are located closer to the pharynx, which makes it possible to breathe freely while food is in the mouth. The sense of smell is better developed than that of amphibians, allowing many lizards to find food that is under the surface of the sand at a depth of up to 6-8 cm.
• The organ of taste is the taste buds located mainly in the pharynx.
• The organ of thermal sensitivity is located on the facial fossa between the eye and nose on each side of the head. Especially developed in snakes. In pit vipers, thermolocators even make it possible to determine the direction of the source of thermal radiation.
• The hearing organ is close to the hearing organ of frogs, it contains the inner and middle ear, equipped with a tympanic membrane, an auditory bone - a stirrup and an Eustachian tube. The role of hearing in the life of reptiles is relatively small; hearing is especially weak in snakes that do not have an eardrum and perceive vibrations propagating along the ground or in water. Reptiles perceive sounds in the range of 20-6000 Hz, although most hear well only in the range of 60-200 Hz (crocodiles have 100-3000 Hz).
• The sense of touch is pronounced, especially in turtles, which can feel even a light touch on the shell.

Respiratory system

Reptiles are characterized by suction-type breathing by expansion and contraction chest with the help of intercostal and abdominal muscles. The air that enters through the larynx enters the trachea - a long breathing tube, which at the end is divided into bronchileading to the lungs. Like amphibians, reptile lungs are sac-like, although their internal structure is much more complex. The inner walls of the lung sacs have a folded cellular structure, which significantly increases the respiratory surface.

Since the body is covered with scales, reptiles do not have skin respiration, and the lungs are the only respiratory organ.

circulatory system

The circulatory system of reptiles

Like amphibians, most reptiles have a three-chambered heartconsisting of one ventricle and two atria. The ventricle is divided by an incomplete septum into two halves: upper and lower. With this design of the heart, a gradient (difference) in the amount of oxygen in the blood is established in the slit-like space around the incomplete septum of the ventricle. After atrial contraction, the arterial blood from the left atrium enters the upper half of the ventricle and displaces the venous blood that has flowed from the right side of the ventricle into the lower half. Mixed blood appears in the right side of the ventricle. When the ventricle contracts, each portion of blood rushes to the nearest opening: arterial blood from the upper half into the right aortic arch, venous blood from the lower half into the pulmonary artery, and mixed blood from the right side of the ventricle into the left aortic arch. Since it is the right aortic arch that carries blood to the brain, the brain receives the most oxygenated blood. In crocodiles, the septum completely divides the ventricle into two halves: the right - venous and left - arterial, thus forming a four-chambered heart, almost like in mammals and birds

In contrast to the common arterial trunk of amphibians, there are three independent vessels in reptiles: the pulmonary artery, and the right and left aortic arches. Each arch of the aorta curves back around the esophagus, and, converging with each other, they are connected to the unpaired dorsal aorta. The dorsal aorta stretches back, sending arteries along the way to all organs. From the right aortic arch, which extends from the left arterial ventricle, the right and left carotid arteries branch off with a common trunk, and both subclavian arteries that carry blood to the forelimbs depart from the right arch.

A complete division into two independent circles of blood circulation in reptiles (including crocodiles) does not occur, since venous and arterial blood are mixed in the dorsal aorta.

Like fish and amphibians, all reptiles are cold-blooded animals.

Digestive system

Due to the variety of food available for food, the digestive tract of reptiles is much more differentiated than that of amphibians.

excretory system

The kidneys of reptiles differ significantly from the kidneys of fish and amphibians, which have to solve the problem of getting rid of a constant excess of water in the body. Instead of the trunk kidneys of amphibians (mesonephros), the kidneys of reptiles (metanephros) are located in the pelvic region on the ventral side of the cloaca and on its sides. The kidneys are connected to the cloaca through the ureters.

Thin-walled stalked bladder connects to the cloaca with a thin neck on its ventral side. In some reptiles, the bladder is underdeveloped (crocodiles, snakes, some lizards).

reproductive system

Reptiles are dioecious animals.

male reproductive system consists of a pair of testes, which are located on the sides lumbar spine. From each testicle, a seminal canal departs, which flows into the wolfian canal. With the appearance of the trunk kidney in reptile wolfs, the canal in males acts only as a vas deferens and is completely absent in females. The Wolffian duct opens into the cloaca to form the seminal vesicle.

female reproductive system represented by the ovaries, which are suspended on the mesentery to the dorsal side of the body cavity on the sides of the spine. The oviducts (Müllerian canals) are also suspended from the mesentery. In the anterior part of the body cavity, the oviducts open with slit-like openings - funnels. The lower end of the oviducts opens into the lower part of the cloaca on its dorsal side.

Lifestyle

Development

Fertilization is internal.

Nutrition

Most reptiles are carnivores. Some (for example, agamas, iguanas) are characterized by a mixed diet. There are also almost exclusively herbivorous reptiles (land turtles).

Economic importance

The value of reptiles for humans is relatively small. The skin of crocodiles, large snakes and lizards is used in the leather industry for the manufacture of suitcases, belts, shoes, etc., however, these items are exclusive, being a luxury item. The meat of some turtles and eggs are eaten. Snake venom is used in medicine. Many snakes are useful in exterminating rodents, and lizards are insects. Some types of reptiles are kept as pets.

The greatest danger to people is Poisonous snakes especially in tropical countries. Large crocodiles are dangerous to humans, causing damage to livestock. Many turtles harm fisheries.

Origin of reptiles

The first representatives of reptiles - cotylosaurs - are known from the Middle Carboniferous. By the end of the period, animal-like reptiles appear, which in the Permian period settled almost throughout the land, becoming the dominant group among reptiles. In the Mesozoic era, the flowering of reptiles begins, among the representatives there is the greatest diversity. There is a development of sea and river reservoirs, as well as airspace. In the Mesozoic, the formation of all groups of reptiles occurs. The last group - snakes - formed in the Cretaceous.

At the end of the Cretaceous period, there is a sharp decrease in the number of reptile species. Unequivocally indicate the causes of extinction modern science cannot yet.

Classification

There is a lot of obscurity in the classification of reptiles, largely because most of them have died out. Below is one of options.

• Subclass Anapsida ( Anapsida)
  • Turtles ( testudines or Chelonia)
  • †Cotylosaurs ( Cotylosauria)
  • † Seymouriomorphs ( Seymouriomorpha)
• Subclass Proganosaurus ( Proganosauria)
  • † Mesosaurus ( Mesosauria)
• Subclass Ichthyopterygia ( Ichtyopterygia)
  • †Ichthyosaurs ( Ichthyosauria)
• Subclass Synaptosaurs ( Synaptosauria or Euryapsida)
  • † Protorosaurs ( Protorosauria)
  • †Sauropterygium ( Sauropterygia)
• Subclass Lepidosaurs or scaly lizards ( Lepidosauria)
  • † Eosuchia ( Eosuchia)
  • beakheads or proboscis ( Rhynchocephalia)
  • scaly ( Squamata): lizards and snakes
• Subclass Archosaurs ( Archosauria)
  • †Thecodonts ( Thecodontia) - became extinct, gave rise to other representatives of this subclass and, possibly, birds
  • Crocodiles ( Crocodylia or crocodilia)
  • †Pterosaurs or flying lizards ( Pterosauria): pterodactyls, etc.
  • † Lizard dinosaurs ( Saurichia) - became extinct, possibly gave rise to birds
  • †Ornithischian dinosaurs ( Ornithischia)
• Subclass Animals, or synapsids, or theromorphs ( synapsida or Theromorpha) - became extinct, but gave rise to mammals.
  • † Pelycosaurs ( Pelycosauria)
  • †Therapsids ( Therapsida)

This lesson will cover the topic "Reptiles. Differences between reptiles and other animals. We learn about the first terrestrial real animals - the Reptile squad. They are well, with the exception of some, adapted to life on land. Consider the main differences between reptiles and other animals.

It consists of a head, body, paired limbs with claws and a long tail. In case of danger, some lizards can drop their tail. Lizard skin is covered with scales, plates, ridges. Their head moves well, their eyes have movable eyelids. Lizards respond well to moving prey, they hear well. Lizards have small teeth and a tongue in their mouths. This tongue is bifurcated, because it is perfectly adapted to hunting. It is also the organ of smell, touch and taste. The food of lizards is varied.

The yellowbell and the brittle spindle have no legs and look like snakes (Fig. 2, 3).

Rice. 2. Yellowbelly ()

Rice. 3. Brittle spindle ()

The agile, green, and viviparous lizards (Figure 4-6) are the most common.

Rice. 4. Quick lizard ()

Rice. 5. Green lizard ()

Rice. 6. Viviparous lizard ()

The marine iguana has mastered the water element, where it feeds (Fig. 7).

Rice. 7. Marine iguana ()

Basilisks have a very frightening appearance, they run on water as if on land (Fig. 8).

Rice. 8. Basilisk ()

The agama family includes the most bizarre lizards - a flying dragon (Fig. 9).

Rice. 9. Flying dragon ()

Moloch impresses with its large and sharp spikes (Fig. 10).

There are poisonous lizards (Fig. 11).

Giant monitor lizards live on Komodo Island (Fig. 12).

Rice. 12. Gigantic monitor lizard ()

Chameleons can change their color and body pattern (Fig. 13).

Rice. 13. Chameleon ()

The gecko can walk upside down (Fig. 14).

In nature, there is even a blue-tongued skink (Fig. 15).

Rice. 15. Blue-tongued skink ()

snakes are also scaly reptiles. They have a long cylindrical body with a tail. The head is usually facial or triangular in shape. Snakes have no legs, their body is covered with scales. Snakes move very well, crawl fast enough. The eyes of snakes are covered with a transparent film, they do not see well and do not hear very well. Snakes have the same language as lizards. They have teeth. Some snakes are venomous. Snakes are predatory animals. They also shed their skin and their body coloration is protective. Among the snakes there are those that strangle the victim, wrapping themselves around in rings. This is a boa constrictor and a python.

There are miniature blind snakes. They can even live in a flower pot (Fig. 16).

Rice. 16. Blind snake ()

The rattlesnake is known for its rattle at the end of its tail. This is a kind of warning about the appearance of this snake (Fig. 17).

Rice. 17. Rattlesnake ()

In nature, there are even two-headed snakes (Fig. 18).

Rice. 18. Two-headed snake ()

There are completely harmless snakes - these are snakes (Fig. 19). In case of danger, they themselves can pretend to be dead.

But the common viper is a viviparous snake (Fig. 20).

Very dangerous and poisonous snakes are taipan (fig. 21) and tiger snake (fig. 22).

Rice. 22. Tiger snake ()

A cobra has a warning before an attack - a swollen hood (Fig. 23).

There are tree flying snakes. When in a tree, they jump straight down in search of prey if necessary.

There is another type of reptile - this turtles. There are about 200 species of them. The body of turtles is usually hidden under a powerful shell, their limbs and neck are keratinized, the shape of the head is pointed, the turtles have no teeth. Turtles have color vision. In case of danger, the turtle hides all the protruding parts of the body under the shell. Turtles can be herbivores and carnivores. In nature, there are land, sea and freshwater turtles. The largest leatherback turtle belongs to the marine ones (Fig. 24).

Rice. 24. Leatherback turtle ()

Green turtle meat is eaten by humans (Fig. 25).

Rice. 25. Green turtle ()

Sea turtles have flat limbs, they do not retract them into the shell. These reptiles are excellent swimmers.

Land turtles less mobile. Among them are centenarians. The sizes are very different. Very large elephant (Fig. 26), and small - spider turtle (Fig. 27).

Rice. 26. Elephant turtle ()

Rice. 27. Spider Turtle ()

The Central Asian turtle hisses like a snake (Fig. 28).

Rice. 28. Central Asian tortoise ()

There are also freshwater turtles - this is the mata-mata fringed turtle. Its appearance is very unusual (Fig. 29).

Rice. 29. Turtle mata-mata ()

The Chinese trionics belongs to soft-bodied turtles (Fig. 30).

Rice. 30. Chinese trionics ()

Caiman turtles are very biting and aggressive (Fig. 31).

Rice. 31. Cayman turtle ()

There are other representatives of reptiles - this is crocodiles. There are about 20 species in nature. Crocodiles are semi-aquatic animals, their skin is covered with shields and plates. They have an elongated, long body. Muscular tail and webbed limbs provide excellent swimming in the water. Crocodiles see and hear well. They have powerful jaws with sharp teeth. Crocodiles swallow their food whole, without chewing. The largest is considered combed crocodile, he can even attack a person (Fig. 32). Its weight reaches over one ton. The Chinese alligator is a symbol of power in its homeland, because it looks like a dragon. In China, it is believed that meeting with a crocodile is good luck.

Caimans are orderlies of reservoirs.

The Ghanaian gharial has a very unusual appearance (Fig. 35). It has surprisingly narrow and long jaws that look like large tweezers. They help to catch the most agile fish.

Rice. 35. Ghanaian gharial ()

In nature, there is another order of reptiles - this beakheads. The most interesting thing is that it consists of only one representative, the tuatara, which is found only in New Zealand. Hatteria has a peculiar body shape. By appearance the tuatara is more like a lizard, its head has a tetrahedral shape, the head and the whole body are covered with scales of various shapes. A ridge of spikes stretches on the neck, back, and tail. In addition to teeth, the tuatara has incisors, like rodents. The shape of the mouth is also unusual like a beak. The most interesting thing is that this reptile has three eyes. The third eye is located on the head and is covered with thin skin. Tuataria are the most cold-loving of all reptiles (Fig. 36).

Rice. 36. Hatteria ()

In the lesson, we were convinced that reptiles are amazing and interesting animals that rightfully occupy an important place in nature. . Consider the most interesting representatives reptiles.

The largest snake is the Anaconda water boa, 11 m 43 cm.

The largest lizard is a monitor lizard from Komodo Island, up to 3 m in length, weighing up to 140 kg.

The largest crocodile is combed, up to 9 m in length, and its mass is approximately 1 ton.

The largest turtle in the sea is leathery, about 3 m, and its weight is 960 kg.

On land, the largest turtle is elephant, 2 m long, weighing up to 600 kg.

The most venomous snakes are taipan, black mamba, tiger snake, rattlesnake, sea snake.

The number of species of reptiles is decreasing, and people are also to blame. Very often a person, because of his fear, destroys and destroys these animals. It must be remembered that, like all living things, reptiles must be protected and protected.

The next lesson will cover the topic “Ancient reptiles and amphibians. Dinosaurs. On it, we will go on a long journey many millions of years ago and get acquainted with ancient reptiles and amphibians, the features of their structure and habitat. We will also learn about animals that became extinct many centuries ago - dinosaurs.

Bibliography

1. Samkova V.A., Romanova N.I. The world 1. - M.: Russian word.
2. Pleshakov A.A., Novitskaya M.Yu. The world around 1. - M .: Education.
3. Gin A.A., Faer S.A., Andrzheevskaya I.Yu. The world around 1. - M .: VITA-PRESS.

1. Mirzhivotnih.ru ().
2. Filin.vn.ua ().
3. Festival of Pedagogical Ideas " Public lesson" ().

Homework

1. Who are reptiles?
2. What are the characteristics of reptiles?
3. Name four orders of reptiles and describe each of them.
4. * Draw a picture on the topic: "Reptiles in our world."

Reptiles are animals belonging to the class of vertebrates. They rank between amphibians and mammals. Their other name is reptiles.

Many reptiles are so unique that even non-professional biologists may be interested in studying this class.

reptiles

Reptiles include the following animals:

• Dinosaurs (fossil form);
• Scaly (lizards, snakes);
• Turtles;
• Tuatara;
• Crocodiles.

Like amphibians, reptiles are cold-blooded creatures. In other words, their body temperature depends on the environment. Some of them, for example, fall into hibernation in winter, and during the intense heat they switch to night hunting. Reptiles have tough, scaly skin that protects the animal's body from drying out. The upper protection of the turtle is a strong shell, and the crocodile has plates of bone origin on the back and on the head.

Reptiles breathe through the lungs. Some animals have the same size lungs and an equal degree of their development, and in snakes and lizards, the right lung is located throughout the body cavity and has big size. Since turtles have fixed ribs due to the shell, air enters the lungs during the movement of the front legs, or when the turtle swallows heavily.

The bone skeleton of representatives of this class is well developed. Each individual has ribs, the shape and number of which depends on the particular species. Turtles almost all have fused bone plates of the shell and spine. The ribs of snakes are very flexible, which allows them to crawl. And lizards have fan-shaped membranes, so the ribs support them, which helps to plan in the air. Many species of reptiles have a short tongue that does not protrude. But snakes and lizards long tongue, extending far from the mouth and divided into two parts.

Reptiles also have a number of abilities that protect them from the environment. For example, small reptiles have an original color. Turtles, on the other hand, are under the reliable protection of a dense shell. Some snakes have poisonous saliva.

Basically, reptiles are oviparous animals, which makes them similar to birds. But in some species, the eggs are located in the oviduct until they hatch. This type includes several species of lizards and vipers.

Dinosaurs are descendants of modern reptiles

From the lessons of history and biology, we know that reptiles appeared back in carboniferous period. The largest individuals appeared in the Permian and Triassic periods, at the same time, an increase in reproduction and settlement of new territories by animals was observed. The Mesozoic era has been called the age of the reptiles because their dominance was overwhelming both on land and in water.

Lizard species

One of the most famous and unique species of lizard is the chameleon. Its uniqueness lies in the coloring, which performs a masking function - the color of the skin may change depending on environmental conditions. Trees are their habitat. Some people keep these animals as pets, but the chameleon is very whimsical to care for. The main condition for its comfortable living is a spacious terrarium equipped with special lamps. It will also be necessary to purchase a tree, there must be a small reservoir, underfloor heating and good ventilation. Their diet mainly consists of insects.

In addition to chameleons, people have recently acquired iguanas more and more often as pets. Representatives of this species of lizards also require special care. They should be kept in a special terrarium in which it is necessary to maintain a certain temperature regime. They feed mainly on fruits, vegetables and herbs. Under good home conditions, lizards can grow up to 5 kg. Keeping such an animal is very difficult and very expensive. Iguanas are one of the species of animals in which molting occurs, stretching for several weeks.

One of major representatives lizard is a monitor lizard. Its dimensions are very impressive: the short-tailed monitor lizard reaches 20 cm in length, while its other representatives are much larger - about 1 meter. Komodo dragons are considered the largest. Their size reaches 3 m, and their body weight is up to one and a half thousand kilograms, they are also called modern dinosaurs. They have a tenacious grip and powerful long tail. Covered with large gray-brown scales. The tongue of the animal is also very large, divided in half. He smells only with his tongue.

They live in Australia, Africa, South Asia - that is, in regions with a warm climate. They are divided into two types, depending on the habitat. The former prefer a desert area with dry trees and shrubs, while the latter are located near water bodies and rainforest. Some representatives of monitor lizards prefer to live on tree branches.

Another unique representative of reptiles are geckos, the peculiarity of which is gluing to any surface, even the smoothest: ceiling, smooth glass walls. This type of lizard is able to stay, in limbo, with just one paw.

Description of snakes

The main difference between snakes and other types of reptiles is the shape of the body. They have a long body, but do not have paired limbs, eyelids and external auditory meatus. Some of these characteristics are certain types lizards, but only the snake shows all these signs together.

The snake body consists of:

• heads;
• Body;
• tail.

Many snakes are venomous. They have furrowed or canalized teeth that contain poison. All internal organs snakes have an oblong shape, there is no bladder. The cornea in front of the eyes was formed from the fused eyelids. The location of the pupil also depends on the lifestyle of snakes: in the nighttime, the pupil is in a vertical position, in the daytime, in a horizontal position. They only hear loud sounds because they don't have an auditory canal.

Already - a snake belonging to the class of reptiles. Its main feature is that it is poisonous. It has large ribbed scales of bright color.. The habitat of snakes is near water bodies. Their reproduction occurs on plant soils covered with moss or natural debris. Their main diet includes amphibians and fish, as well as, with rare exceptions, if they can be caught, birds or small mammals. They swallow their prey whole. When danger is felt, the snake pretends to be dead, and if it is attacked, a liquid of a very unpleasant odor is released from its mouth.

Crocodiles - amphibians or reptiles

The crocodile is the largest of modern reptiles and the most dangerous. Ancient representatives of this species exceeded a length of more than 15 meters. Judging by the remains found, crocodiles lived on all continents. modern reptiles significantly smaller than their ancestors, but at the same time they are still the largest reptiles.

They spend most of their lives in the water. Only the organs of sight, hearing and nose remain on the surface. The tail and paws are webbed, making them excellent swimmers. However, they prefer to be in shallow water. They come to land to breed and to warm themselves. They have a substantial tail size and are very fast both in water and on land. Attack stealthily and unexpectedly and therefore are especially dangerous to humans.

Tuatara Features

The tuatara, best known as the tuatara, is a very rare reptile that is the only representative of its kind. Belongs to the ancient order of beakheads and the family of wedge-toothed.

An unknowing person can confuse a hatteria with a fairly large lizard. But there are a number of differences between the representatives of these two types of reptiles. Body weight of adult males twice the mass of a mature female of this species and is about a kilogram. The length of the body along with the tail is about 65-75 cm. If you find a picture (photo) on the Internet, you can see that the animal has an olive-green or greenish-gray color on the sides of the body. On the limbs there are spots of various sizes of yellowish color.

A common resemblance to the iguana is that a crest runs along the entire surface of the back from the back of the head to the tail, which is represented by triangular plates. Hence the other name of this animal - Tatars, which translates as "prickly".

Despite the fact that the hatteria is outwardly very similar to a lizard, it has long been attributed to the order of beakheads. This is explained by the structure of the body of the animal, and in particular, the head area. The structure of the cranium of the tuatara has interesting feature - upper jaw, the lid of the skull and the palate have a pronounced mobility relative to the box of the brain.

It is proved that the tuatara originated from a terrestrial vertebrate- a brush fish, from which she inherited such a feature. Particular attention also deserves the presence of a reptile parietal or third eye, located in the back of the head. This organ has light-sensitive cells and a lens, and it completely lacks the muscles that are responsible for focusing the location of the eye. With age, the parietal eye overgrows and is practically indistinguishable in adults.

Animals show activity only at low temperatures, in hot weather they hide in deep holes. They lead a not too mobile lifestyle, and hibernate in winter. Another feature of the beakheads is that they swim very well and can hold their breath for up to an hour. The life expectancy of these animals in the wild is about 100 years.

Hatteria living in wild nature has an excellent appetite. Her diet includes:

• Insects;
• frogs;
• Spiders;
• Mice;
• Lizards.

She also destroys bird nests, eats eggs and newborn chicks, and catches small birds.

In the midst of summer, which begins in the Southern Hemisphere around the last ten days of January, this reptile starts the process of active reproduction.

After fertilization female after nine or ten months lays eggs (their number is from eight to fifteen) in minks, burying them with earth and stones, after which they are incubated. Incubation period takes about fifteen months.

A group of scientists from one of the leading Wellington Universities conducted unusual and interesting experiments, during which they managed to get the relationship between temperature indicators and the sex of the hatched offspring of the hatteria. If incubation occurs at a temperature of 18 ° C, then females are born, and at a temperature of 22 ° C, only males are born.

And this is not the whole list of modern reptiles. It can be continued ad infinitum. All representatives of the class are united by certain similarities, but they also have many clear differences. These animals are of massive interest to scientists and hobbyists around the world. In Russia, there are about 80 species of reptiles.