What are the reptiles. Groups of modern reptiles: representatives, brief description, signs and photos. Crocodile habitats

Reptiles are unusual classwhich sits between amphibians and mammals. In another way, they are called reptiles. But not everyone knows who the reptiles are.

Reptiles are vertebrates that resemble birds and mammals.

Let's take a closer look at this class.

Who are the reptiles

Representatives of this class are cold blooded creatures... Their body temperature is determined by the temperature environment... But they have one feature, they can regulate their own temperature. The ancestors of reptiles are amphibians. In winter, reptiles tend to sleep. And in hot weather they lead only a nocturnal lifestyle.

Reptile skin is tough and scaly.... Such skin is needed in order to protect the body from drying out. These animals breathe only through the lungs. Some members of this class have lungs of the same size, while others have one lung larger than the other. And this is the norm. The skeleton of reptiles is well developed. Everyone has ribs, but their number depends on the representative of this class.

Almost all species of this class have a language, but for some it is short, while for others it is very long. It is also the main sense organ. To protect themselves from enemies, these animals change color, some have a hard shell, and some are generally poisonous. These animals reproduce like birds, that is, they lay eggs.

The following animals belong to the class of reptiles:

• Snakes;
• Lizards;
• Turtles;
• Dinosaurs.

Reptile types

Reptiles or reptiles are divided into four orders:

Reptiles can be found anywhere, but most of them live in warm countries... Where it is always cold and little vegetation, these animals are very rare. Reptiles are everywhere... And in water, and on land, and in the air. Let's take a closer look at the representatives of this class.

Turtles

Turtles are the most famous among reptiles. They can live both on land and in water. They can be seen not only in the zoo and in wildlife, many keep them at home. These cute animals do not pose any danger to humans, they are harmless.

Turtles appeared about two hundred million years ago. These reptiles have a shell. He protects them from enemies. It consists of two parts: ventral and dorsal. From above, it is covered with horny tissue in the form of plates.

These animals come in different sizes... There are giant turtles that can reach 900 kilograms. And there are little turtles. Their mass does not exceed 125 grams, and the length of the shell is only ten centimeters.

Instead of teeth, this animal has a powerful beak. With the help of it, she grinds food.

According to their habitat, turtles are divided into:

• Freshwater: painted or decorated, European marsh, red-eared, caiman;
• Marine: turtle bisse, leathery, green or soup;
• Terrestrial;
• Land: elephant, Egyptian, Central Asian, leopard, Cape;

What do these animals eat?... Their food depends entirely on their habitat. Land turtles feed on fruits, vegetables, tree branches, mushrooms and grass. And sometimes they can even eat worms and snails.

Water turtles feed on small fish, shrimps, squid, frogs, snails, molluscs, insects, bird eggs.

Land turtleswho live at home eat cabbage, apples, tomatoes, beets, cucumbers, dandelions, chicken eggs. And water turtles love to feast on earthworms, boiled meat, bloodworms, insects, algae and lettuce.

The turtle is a long-liver. She will outlive any other reptile.

Crocodiles

Crocodile

The crocodile is the only member of the archosaur subclass. Their body length ranges from two to seven meters. And the mass can reach more than 700 kilograms. The crocodile is a fairly fast animal in the water. Its speed can reach forty kilometers per hour.

The number of teeth in a crocodile ranges from 70 to 100. It depends on the type of crocodile. The teeth are long and sharp, about five centimeters.

These animals live only in warm countries with a humid climate: Africa, Japan, Australia, Bali, North and South America, Guatemala, Philippine Islands.

Crocodile is a predator, so it feeds on fish, shellfish, birds, lizards, snakes, antelopes, deer, buffaloes, wild boars, dolphins, sharks, leopards, lions, hyenas. These animals can even eat monkeys and porcupines, kangaroos and bunnies. And there are times when crocodiles eat their own kind.

Crocodiles live for a long time - a hundred years.

Variety of crocodiles

Crocodiles are divided into three families: true crocodiles, gavial and alligator.

In its turn, crocodiles of the real family are divided into the following types:

The alligator family is divided into:

• Mississippi - differ from other species in that they can easily endure the cold, freezing their whole body into the ice.
• Chinese is a rare and small species of alligators. Its length does not exceed two meters, and it weighs only about forty-five kilograms.
• Crocodile caiman - otherwise it is called spectacle crocodile. This is due to the fact that there are growths on his face between the eyes that resemble glasses.
• Black caiman - pretty large view alligator. Its length reaches 5.5 meters, and it weighs over 500 kilograms.

The gavial family is divided into:

• Ganges gavial. Its body length reaches six meters, and it weighs only about two hundred kilograms.
• Gavial. The muzzle of this species is narrow and long. The body length is six meters, and the weight does not exceed 200 kilograms.

Tuatara

Most people believe that tuatara is lizard. But this is a misconception. This reptile lived in the era of dinosaurs and forms a detachment of beakheads. This reptile has one more name - tuatara.

They live only in New Zealand. In appearance, they resemble an iguana. Internally, the structure looks like a serpentine. They took something from turtles, and something from crocodiles.

It also has one more feature - three eyes... The third eye is located at the back of the head. The length of the tuatara reaches more than fifty centimeters, and it weighs no more than one kilogram.

This amazing animal is only nocturnal. Slow breathing of the tuatara. She may not breathe for sixty minutes.

This reptile feeds on insects, snails, worms. The life span is quite long, about a hundred years.

Lizards

Lizards belong to the class of reptiles... Their diversity is very large - about six thousand species. They all differ from each other in their size, color, habitat.

Lizards are very similar to newts, but they have many differences. One of the main differences is that the newt is an amphibian. And an amphibian animal is different from a reptile.

Almost all lizards have the characteristic is the ability to dump your tail in an emergency. Many lizards can change their body color.

Lizards feed on insects: butterflies, snails, grasshoppers, spiders, worms. Large representatives feed on small animals, snakes and frogs.

Lizards are divided into six infraorders:

• Skincare;
• Iguaniformes;
• Gecko-like;
• Fusiform;
• Worm-like;
• Monitors

All these infraorders are divided into families. Skins are divided into:

Iguana are divided into fourteen families. The most prominent representative of this infraorder is the chameleon.

Gecko are divided into seven families. Of which an unusual lizard can be distinguished is the scalefoot. The peculiarity of this reptile is that it has no legs.

Fusiform is divided into five families: earless lizards, spindle lizards, legless lizards, monitor lizards, xenosaurs.

Worm-like lizards consist of one family. These reptiles are like earthworms.

Lizards consist of several families. They are the largest lizards. For example, a Komodo dragon can weigh over ninety kilograms.

Snakes

The snake is a cold blooded animal, which belongs to the class of reptiles. The weight and size of snakes varies. Their length can reach nine meters, and their weight is more than one hundred kilograms.

Snakes are poisonous and non-poisonous. These reptiles are deaf. They are guided by the language. It is he who collects information about the environment.

Snakes feed rodents, bird eggs, fish, and some even feed on their own kind. They eat food only twice a year.

Snakes are oviparous. Someone lays ten eggs, and someone one hundred and twenty thousand eggs. Some representatives give birth to live cubs.

The variety of snakes is huge. There are more than three thousand species of them.

The most interesting representatives are the following:

Now you know who the reptiles or reptiles are. And who are their representatives.

Snakes are unusual appearance and behavior, attracting the undying interest of scientists and reptile enthusiasts. The emergence of these reptiles on the planet is attributed to the Cretaceous period, but their ancestors, ancient lizards, appeared much earlier, in the Paleozoic. And in this article you will find out what significance this reptile has in magic and everyday life.

The first reptiles arose on the territory of Africa more than 200 million years ago, later spreading throughout the world, except for Antarctica.

The habitats of animals are tropical areas, forests, steppes, mountain slopes and foothills. Reptiles can live in water, on land and trees. Sea snakes went into deep ocean waters, breeding offspring far from coastal zones. Reptiles also inhabit freshwater lakes and rivers. Species diversity there are about 3 thousand snakes, which are united in 23 families.

General characteristics of scaled reptiles

Many species are poisonous, and some reptiles are capable of inflicting deadly bites. Certain species use venom to paralyze prey. The elongated body of reptiles is completely covered with scales.

Some species can be up to 12 meters in length. The smallest snakes are only 8 cm long. Predators feed on insects, frogs, fish, bird eggs and small mammals. Certain species are capable of swallowing prey several times the size of reptiles.

Reptile skin color is varied and often matches the color scheme of the natural setting of the environment. At first glance, bright colors reliably hide reptiles in rainforest, among lush greenery.

Some snakes are distinguished by variegated skin patterns even in rather faded environments, signaling others about danger. There are species that show a warning color only at the moment of danger.

Duality of the image in ancient mythology

In ancient times, snakes were a rather controversial symbol, combining the positive concepts of fertility, immortality, wisdom and negative ones - evil, duplicity. The duality was based on the poisonousness of reptiles, which brought death, and on the ability to regenerate and revive, shedding the skin. The animal is a symbol of healing and medicine.

Legends tell about the wisdom of these reptiles who know the secret of eternal life and the secrets of healing recipes. The way ancient god Asclepius raised from the dead, an image appeared in the form of a staff entwined with a snake.

Among the huge variety of reptiles, it was the snakes that were the symbol of healing. The snake was called the serpent Aesculapius and was revered in Rome and. The symbol of modern medicine is depicted in the form of a cup with a medicine entwined with a snake.

Already

In Antiquity, the reptile was a sacred animal of the goddess Athena. In Egypt, the appearance of the goddess Isis was represented in the form of a half woman, half a snake. Egyptian mythology associated the image of a snake with the Sun, as an attribute of the god Osiris. The snake combines cunning and deceit, dark forces and evil. Ancient beliefs endowed reptiles with the qualities of an intermediary between the earthly and other worlds.

The symbol of the reptile in the culture of eastern countries

The culture of China is filled with ancient legends and traditions associated with snakes. In most legends, reptiles embody negative symbols and evil. Legends Of the Far East do not differentiate between dragons and snakes.

Dragons acted as guardians of the temples, guarding esoteric knowledge and treasures. There is an opinion that represents a closed snake in a circle, as a reflection of the concept of yin-yang, symbolizing harmony and eternity.

The animal was considered bisexual, personifying fertility. The chthonic nature of the reptile embodied the power of dark magic and omniscience. Due to their ability to slide without the aid of limbs, reptiles were considered an all-pervading creature capable of overcoming any obstacle.

The black sun served as the image of sorcerers and witches, representing sin and the dark forces of nature. The Heavenly Serpent, or Azure Dragon, was a symbol of the rainbow, embodying the transition between worlds. In Japan, this animal is an invariable attribute of the storm gods and thunders.

The embodiment of the image in Christianity

The image of this reptile in Christianity is considered in two ways, combining wisdom and the chthonic symbol of the devil. The personification of the Fall and everything dark that must be overcome by man. The animal entwining the Tree of Life was a positive symbol, the snake on the Tree of Knowledge is the dark beginning, Lucifer.

The reptile, depicted with a female head, represented temptation. In Christian beliefs and culture, the animal personifies the negative image of a poisonous creature with the ability to wriggle, using lies and cunning. Popular beliefs endowed negative heroes with a "serpentine heart", implying anger and deceit of images.

Greek legends represent the serpent, symbolizing healing and renewal. In Jewish legends, a reptile is always evil and sin. The image is widely represented in almost all mythologies and cultures of the world. The symbol was often associated with fertility, male and female principles, and the hearth. Many magical texts refer to these animals as intermediaries between the worlds.

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Representatives of reptiles (more than 4 thousand species) are real terrestrial vertebrates. In connection with the appearance of embryonic membranes, they are not associated with water in their development. As a result of the progressive development of the lungs, adult forms can live on land in all conditions. Reptiles living in the species are secondary aquatic, i.e. their ancestors moved from a terrestrial lifestyle to an aquatic one.

Remember! Reptiles and reptiles are the same class.!

Reptiles, or reptiles, appeared at the end of the Carboniferous period, about 200 million years BC. when the climate became dry, and even hot in places. This created favorable conditions for the development of reptiles, which turned out to be more adapted to living on land than amphibians. The advantage of reptiles in competition with amphibians and their biological progress was facilitated by a number of traits. These include:

• Sheaths around the embryo and a strong shell (shell) around the egg, protecting it from drying out and damage, which made it possible to reproduce and develop on land;
• development of five-toed limbs;
• improvement of the structure of the circulatory system;
• progressive development of the respiratory system;
• the appearance of the cerebral cortex.

The development of horny scales on the surface of the body, which protect against adverse environmental influences, primarily from the drying effect of air, was also important. The prerequisite for the emergence of this adaptation was the release from cutaneous respiration in connection with the progressive development of the lungs.

A typical representative of reptiles can be a fast lizard. Its length is 15-20cm. She has a well-expressed patronizing color: greenish-brown or brown, depending on the habitat. During the day, lizards are easy to see in the sun-warmed area. At night, they crawl under stones, into holes and other shelters. They spend the winter in the same shelters. Their food is insects.

On the territory of the CIS, they are most widespread: in the forest zone - the viviparous lizard, in the steppe - the fast lizard. The spindle belongs to lizards. She reaches 30-40 cm, has no legs, which resembles a snake, it often costs her life. Reptile skin is always dry, devoid of glands, covered with horny scales, scutes or plates.

The structure of reptiles

Skeleton... The vertebral column is already subdivided into cervical, thoracic, lumbar, sacral and caudal regions. The skull is bony, the head is very mobile. The limbs end in five toes with claws.

The muscles of reptiles are much better developed than those of amphibians.

Digestive system... The mouth leads to the oral cavity, equipped with a tongue and teeth, but the teeth are still primitive, of the same type, they serve only to capture and hold prey. The alimentary canal consists of the esophagus, stomach, and intestines. On the border of thick and small intestine the rudiment of the cecum is located. The intestines end with a cloaca. The digestive glands are developed: pancreas and liver.

Respiratory system... The airways are much more differentiated than in amphibians. There is a long trachea that branches into two bronchi. The bronchi enter the lungs, which look like cellular, thin-walled bags, with a large number of internal septa. The increase in the respiratory surfaces of the lungs in reptiles is associated with the lack of cutaneous respiration.

Excretory system represented by the kidneys and ureters flowing into the cloaca. The bladder also opens into it.

Circulatory system... Reptiles have two circles of blood circulation, but they are not completely separated from each other, due to which the blood is partially mixed. The heart is three-chambered, but the ventricle is divided by an incomplete septum.

Crocodiles already have a real four-chambered heart. The right half of the ventricle is venous, and the left part is arterial - from it the right aortic arch originates. Converging under the spinal column, they join to form an unpaired dorsal aorta.

Nervous system and senses

The reptile brain differs from the brain of amphibians by the large development of the hemispheres and cerebral vault, as well as the isolation of the parietal lobes. Appears for the first time, the cerebral cortex. 12 pairs of cranial nerves branch off from the brain. The cerebellum is somewhat more developed than in amphibians, which is associated with a more complex coordination of movements.

At the front end of the lizard's head is a pair of nostrils. The sense of smell in reptiles is better developed than in amphibians.

The eyes have eyelids, upper and lower, in addition, there is a third eyelid - a translucent blinking membrane that constantly moisturizes the surface of the eye. A rounded eardrum is located behind the eyes. Hearing is well developed. The organ of touch is the tip of a forked tongue that the lizard constantly sticks out of its mouth.

Reproduction and regeneration

Unlike fish and amphibians, which have external fertilization (in water), in reptiles, as in all non-aquatic animals, fertilization is internal, in the body of the female. The eggs are surrounded by embryonic membranes that support development on land.

A fast lizard female lays 5-15 eggs in a secluded place in early summer. Eggs contain nutritious material for the developing embryo, and are surrounded by a leathery shell on the outside. A young lizard, similar to an adult, emerges from the egg. Some reptiles, including some species of lizards, are ovoviviparous (i.e., a cub immediately emerges from a laid egg).

Many species of lizards, being grabbed by the tail, break it off with sharp lateral movements. Dropping the tail is a reflex response to pain. This should be seen as a device through which the lizards escape from enemies. A new tail grows in place of the lost tail.

The variety of modern reptiles

Modern reptiles are divided into four orders:

• Primal lizardmen;
• Scaly;
• Crocodiles;
• Turtles.

First lizardmen represented by a single species - tuberculosis, which belongs to the most primitive reptiles. The tuatara lives on the islands of New Zealand.

Lizards and snakes

Scaly species include lizards, chameleons, and snakes.... This is the only relatively large group of reptiles - about 4 thousand species.

Lizards are characterized by well-developed five-toed limbs, movable eyelids and the presence of a tympanic membrane. This order includes agamas, gila moths - poisonous lizards, monitor lizards, real lizards, etc. Most of the species of lizards are found in the tropics.

Snakes are adapted to crawl on their belly. Their neck is not pronounced, so that the body is divided into a head, torso and tail. The spinal column, in which there are up to 400 vertebrae, thanks to additional joints, has great flexibility... The belts, limbs and sternum are atrophied. Only a few snakes have a pelvic rudiment.

Many snakes have two venomous teeth on their upper jaws. The tooth has a longitudinal groove or duct through which the poison flows into the wound when bitten. The tympanic cavity and membrane are atrophied. The eyes are hidden under transparent skin, without eyelids. The skin of the snake on the surface becomes keratinized and periodically shed, i.e. molting occurs.

Snakes have the ability to open their mouths very wide and swallow their prey whole. This is achieved by the fact that a number of skull bones are connected movably, and the lower jaws are connected in front by a very extensible ligament.

In the CIS, the most common snakes: snakes, coppers, snakes. The steppe viper is listed in the Red Book. For her habitat, she avoids agricultural land, but lives on virgin lands, which are becoming less and less, which threatens her with extinction. Feeds on steppe viper (like other snakes) are predominantly murine rodents, which is certainly useful. Its bite is poisonous, but not fatal. She can attack a person only by chance, being disturbed by him.

Bites poisonous snakes - cobras, efy, gyurza, rattlesnake and others - can be fatal to humans. Of the fauna, the gray cobra and sandy efa, which are found in Central Asia, as well as gyurza, found in Central Asia and Transcaucasia, the Armenian viper, inhabiting the Transcaucasia. The bites of the common viper and the mucus are very painful, but usually not fatal to humans.

The science that studies reptiles is called herpetology.

IN recent times snake venom is used in medicinal purposes... Snake venom is used for various bleeding as a styptic. It turned out that some drugs obtained from snake venom reduce pain in rheumatism and diseases nervous system... To obtain snake venom in order to study the biology of snakes, they are kept in special nurseries.

Crocodiles are the most highly organized reptiles with a four-chambered heart. However, the structure of the partitions in it is such that venous and arterial blood partially mix.

Crocodiles are adapted to an aquatic lifestyle, and therefore have swimming membranes between the fingers, valves that close the ears and nostrils, and a palatine curtain that closes the pharynx. Crocodiles live in fresh waters, go ashore to sleep and lay eggs.

Turtles - covered above and below with a dense shell with horny shields. Their ribcage is immobile, so the limbs take part in the act of breathing - when they are drawn in, air leaves the lungs, when protruding, it enters them. Several species of turtles live in Russia. Some species are used for food, including the Turkestan tortoise that lives in Central Asia.

Ancient reptiles

It has been established that in the distant past (hundreds of millions of years ago) on Earth were extremely common different kinds reptiles. They inhabited land, water, and less often air. Most of the species of reptiles became extinct due to climate change (cooling) and the flourishing of birds and mammals with which they could not compete. Extinct reptiles include orders of dinosaurs, animal-toothed dinosaurs, ichthyosaurs, flying dinosaurs, etc.

Dinosaur Squad

This is the most diverse and numerous group of reptiles that have ever lived on Earth. Among them were both small animals (the size of a cat and less), and giants, the length of which reached almost 30m, and the mass - 40-50 tons.

Large animals had small heads, long necks and powerful tail. Some dinosaurs were herbivores, others were carnivorous. The skin either had no scales, or was covered with a bony shell. Many dinosaurs ran in jumps on their hind legs, leaning on their tail, while others moved on all four legs.

Squad Feraltooth

Among the ancient terrestrial reptiles were representatives of the progressive group, which resembled animals in the structure of their teeth. Their teeth were differentiated into incisors, canines and molars. The evolution of these animals went in the direction of strengthening their limbs and belts. In the process of evolution, mammals arose from them.

The origin of reptiles

Fossil reptiles are of great importance, since they once dominated the globe and not only modern reptiles, but also birds and mammals originated from them.

Living conditions at the end of the Paleozoic changed dramatically. Instead of a warm and humid climate, cold winters appeared and a dry and hot climate... These conditions were unfavorable for the existence of amphibians. However, under such conditions, reptiles began to develop, in which the skin was protected from evaporation, a terrestrial way of reproduction, a relatively highly developed brain and other progressive signs, which are given in the characteristics of the class, appeared.

Based on the study of the structure of amphibians and reptiles, scientists came to the conclusion that there is a great similarity between them. This was especially true for ancient reptiles and stegocephals.

• In very ancient lower reptiles, the vertebral column had the same structure as in the stegocephalus, and the limbs - as in reptiles;
• the cervical region in reptiles was as short as in amphibians;
• the sternum was missing, i.e. real chest they haven't had it yet.

All this suggests that reptiles evolved from amphibians.

Larval stage. Most reptiles are oviparous, although there are viviparous species.

Reptiles range in size from a tiny gecko ( Sphaerodactylus ariasae), with a maximum body length of about 18 mm, to a crested crocodile ( Crocodylus porosus), which can reach 6 m in length and weigh over 1000 kg.

Reptiles are common except for all. Depending on the species, they can inhabit both land and water.

The modern classification distinguishes the following 4 orders of reptiles:

Beakhead squad

Beakheads ( Rhynchocephalia) - a detachment of lizard-like reptiles, which includes only one living genus, the tuatara (tuatara). In turn, this genus ( Sphenodon) includes two types: Sphenodon punctatusand Sphenodon guntheri... According to some sources, the genus contains one species Sphenodon punctatus, which is divided into two subspecies - Sphenodon punctatus punctatus and Sphenodon punctatus guntheri... The squad members live only in some areas of New Zealand.

Despite the current lack of diversity, the squad Rhynchocephalia at one time included a large number of genera and families, and it can be traced back to.

The tuatara grows up to 80 cm in length, from head to tail, and weighs up to 1.3 kg. Along the back, this animal has a spiny crest, which is especially pronounced in males. Tuatars are also distinguished by the presence of a pronounced parietal eye (third eye). Animals can hear, although the outer ear is absent and tuataras have unique skeletal features.

Tuatars, like many of New Zealand's endemic animals, are endangered due to the loss and introduction of invasive ones.

Squad Crocodiles

Combed crocodile

Crocodiles ( Crocodylia) - a detachment of large, predatory reptiles, which includes 24 species. It includes: caimans, alligators, real crocodiles, gavials, etc. Crocodiles have powerful jaws with a large number of tapered teeth and short legs, with claws and webbed toes. They have a unique body shape that allows the eyes, ears and nostrils to float above the surface of the water while most of the animal's body is submerged. The crocodile's tail is long and massive. The skin of these reptiles is thick and covered with horny scales.

Crocodiles are the closest living relatives. A wide variety of crocodile fossils have been discovered that have lived for over 200 million years in the later. They are the largest and heaviest modern reptiles. The largest representatives of the detachment - nile crocodile (Crocodylus niloticus) and combed crocodile ( Crocodylus porosus) - reach a body length of up to 6 m and a weight of more than 1000 kg. For comparison, the smallest representatives of the order are smooth-headed caimans ( Paleosuchus) and blunt crocodiles ( Osteolaemus tetraspis), are about 1.7 m long.

Crocodiles are found mainly in the low-lying, humid tropics and.

Turtle Squad

Spurred turtle

Turtles ( Testudines) - a detachment of reptiles, including about 300 species of turtles living on land and in water (fresh and salty) on all continents, except.

The earliest known representatives of this order existed about 220 million years ago, which makes turtles one of the oldest reptiles. Some species are endangered.

Turtles range in size from less than 10 cm ( Sternotherus depressus) up to more than 2.5 m, (leatherback turtle - Dermochelys coriacea). Some species live in cold climates with a breeding season of only about three months; others inhabit tropical regions and reproduce all year round... Some turtles rarely see water, while others spend almost their entire life in it, be it one small pond or.

The shell is a unique adaptation of turtles that protects them from predators. It has various modifications and shapes to meet the protection, feeding and movement needs of turtles.

Squad Scaled

Anaconda

Scaly ( Squamata) is the most numerous order of reptiles, including lizards, chameleons, two-walkers and snakes. Consisting of more than 10,000 species, the scaly ones are also the second largest order of the existing, after the perch-like (containing about 41% of bony fish).

Representatives of the order are distinguished by their skin, consisting of horny scales. They also have movable square bones. This is especially noticeable in snakes, which are able to open their mouths very wide in order to swallow relatively large prey.

The scaled ones come in various sizes, from the 16 mm dwarf gecko ( Sphaerodactylus ariasae) up to more than 5 m of green anaconda ( Eunectes murinus). The order also includes the now extinct mosasaurs, which reached a body length of about 15 m. Among other reptiles, the scaly ones are most closely related to the beak-headed ones, which strongly resemble lizards.

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, go into hibernation in winter, and during 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 lung size and the same degree of 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 intensively.

The bone skeleton of representatives of this class is well developed. Each individual has ribs, the shape and number of which depends on the specific species. Almost all turtles have fused bony 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 contributes to gliding in the air. Many species of reptiles short tonguethat does not protrude. But snakes and lizards have a long tongue that extends far from the mouth and is 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, however, are under the reliable protection of a dense shell. Some snakes have poisonous saliva.

Mostly reptiles are egg-laying animals, which makes them similar to birds. But in some species, eggs are located in the area of \u200b\u200bthe oviduct until hatching. This type includes several types of lizards and vipers.

Dinosaurs are descendants of modern reptiles

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

Lizard species

One of the most famous and unique lizard species is the chameleon. Its uniqueness lies in the coloration, which performs a masking function - the color of the skin can change depending on environmental conditions. Their place of residence is trees. Some people keep these animals as pets, but the chameleon is very whimsical to care for. The main condition for his comfortable living is a spacious terrarium equipped with special lamps. You will also need 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 are increasingly adopting iguanas 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. With good home conditions, lizards can grow up to 5 kg. Keeping such an animal is very difficult and very expensive. Iguanas are animals that moult over a period of several weeks.

One of the largest representatives of lizards is the monitor lizard. Its size is quite impressive: the short-tailed monitor lizard reaches 20 cm in length, while its other representatives are much larger - about 1 meter. Komodo lizards 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 animal's tongue is also very large, divided in half. Smells only with the tongue.

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

Another unique representative of reptiles are geckos, a feature of which is adhesion to any surface, even the smoothest: ceiling, glass smooth walls. This type of lizard is able to stay suspended with just one leg.

Description of snakes

The main difference between a snake and other reptile species is its body shape. They have a long body, but do not have paired limbs, eyelids and external auditory canal. Some of these characteristics are possessed by individual species of lizards, but only the snake has all these characteristics together.

The snake body consists of:

• Heads;
• Body;
• Tail.

A large number of snakes are poisonous... They have grooved or canalized teeth that contain venom. All internal organs snakes have an oblong shape, there is no bladder. The cornea on the eyes was formed from accrete eyelids. The location of the pupil also depends on what lifestyle the snakes lead: in the night pupil it is in the vertical position, in the daytime pupil it is in the horizontal position. They hear only loud sounds, as they have no ear 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 it is possible to catch, birds or a small mammal. They swallow their prey whole. When it senses danger, 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. The ancient representatives of this species exceeded more than 15 meters in length. Judging by the remains found, crocodiles lived on all continents. Modern reptiles are significantly smaller than their ancestors, but at the same time they are still the largest reptiles.

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

Features of tuatara

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

An ignorant person may confuse the tuatara with a fairly large lizard. But there are a number of differences between the representatives of these two species of reptiles. Body weight of adult males twice the mass of a sexually mature female of this species and is about a kilogram. The length of the body, including the tail, is somewhere between 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 extremities there are yellowish spots of various sizes.

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

Despite the fact that the tuatara is very similar in appearance to a lizard, it has long been attributed to the order of beak-headed. This is explained by the structure of the body of the animal, and in particular, by the area of \u200b\u200bthe head. The structure of the skull of the tuatara has interesting feature - the upper jaw, skull lid and palate have a pronounced mobility relative to the box of the brain.

It is proved that the tuatara has occurred from terrestrial vertebrate - cisperfish, from which she inherited this feature. Particular attention is also paid to the presence of a parietal or third eye located in the occiput in the reptile. This organ has light-sensitive cells and a lens, and it completely lacks the muscles that are responsible for focusing the position of the eye. With age, the parietal eye grows overgrown and is practically indistinguishable in adults.

Animals show activity only when low temperatures, in hot weather they hide in deep burrows. They do not lead a very mobile lifestyle, and in winter they hibernate. Another feature of the representatives of the beak-headed order is that they swim very well and can hold their breath for up to an hour. The life span of these animals in the wild is about 100 years.

The wild-living tuatara has an excellent appetite. Her diet includes:

• Insects;
• Frogs;
• Spiders;
• Mice;
• Lizards.

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

At the very height of summer, which begins in the Southern Hemisphere around the last decade 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 burrows, burying them with earth and stones, after which they are incubated. The incubation period takes about fifteen months.

A group of scientists from one of the leading Universities of Wellington conducted unusual and interesting experiments, during which they managed to obtain the relationship between temperature and sex of hatched offspring. 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 indefinitely. All members of the class share certain similarities, but they also have many clear differences. These animals are of great interest to scientists and hobbyists around the world. In Russia, there are about 80 species of reptiles.