Orders of modern reptiles: representatives, brief description, characteristics and photos. Snakes: features of reptiles and embodiment in cultures of the world Who are reptiles

The class of vertebrates that occupy an intermediate position between amphibians and mammals is called reptiles. They are more similar to birds. The following animals belong to this class according to the list:

• crocodiles;
• turtles;
• snakes;
• lizards;
• dinosaurs (fossil form of animals of the Mesozoic era).

General characteristics of reptiles

Like amphibians, reptiles are cold-blooded creatures. In other words, their body temperature is determined by their surroundings. To some extent, reptiles are able to regulate their temperature by covering themselves against hypothermia. For example, in the winter season, animals hibernate, and during periods of extreme heat they begin hunting at night.

Reptiles have tough skin covered with scales. The main task of which is to protect the body from drying out. For example, in turtles the upper protection is provided by a durable shell, crocodiles have hard plates of bone origin on their head and back.

Reptiles breathe only through the lungs. In some animal species, the lungs are the same size and equally developed, while in others, such as snakes and lizards, the right lung is larger and is located throughout the body cavity. Turtles have fixed ribs due to their shell, so the ventilation of the body is organized in a different way. Air enters the lungs during rocking movements of the front legs or during intense swallowing.

The bony skeleton of reptiles is quite well developed. The number and shape of ribs depends on the specific species, but all representatives of the class have them. Almost all turtles have fused bony plates of the shell and spine. Snakes have ribs designed for active crawling. In lizards, the ribs serve to support fan-shaped membranes for gliding in the air.

Most reptiles have a short tongue that cannot protrude. Snakes and lizards have a long tongue, divided in two, which can extend far from the mouth. For this species of animal these are the most important sense organs.

To protect themselves from the environment, small reptiles have original coloring. Turtles are reliably protected by a dense shell. Some snakes are poisonous.

In terms of reproductive organs, reptiles are similar to birds. As a rule, reptiles are oviparous animals. But in some species, eggs remain inside in the oviduct until hatching. This type includes some species of lizards and vipers.

Classification of reptiles and their distribution

Modern reptiles are divided into four groups:

• turtles (about 300 species);
• crocodiles (25 species);
• scaly (about 5,500 species of lizards and snakes);
• tuatara (tuatara).

The last order belongs to the only representative of beaked animals among reptiles.

Reptiles distributed throughout the world. The greatest numbers are seen in warm areas. In regions with a cold climate and a lack of woody vegetation, reptiles are practically not found. Representatives of this class live on land, in water (fresh and salty) and in the air.

Ancient reptile fossils

Reptiles have been known since the Carboniferous period. They reached their largest sizes in the Permian and Triassic periods. At the same time, there was an increased reproduction of animals that populated more and more new territories. In the Mesozoic era, the dominance of reptiles was overwhelming, both on land and in water. It is not for nothing that this period was called the Age of Reptiles.

Turtles

One of the most famous species of reptiles are turtles. There are both marine and land representatives of animals. The species is distributed throughout the world. Animals are also allowed keep at home. The most ancient representatives of turtles were discovered 200 million years ago. Scientists believe that they descended from a primitive species of cotylosaurs. Turtles are practically harmless animals, they are not dangerous to people.

Animals of this species have a shell of a bone structure. On the outside, it is formed by numerous individual elements of horny tissue, which are connected by plates. Land turtles have excellent lung function for breathing. Aquatic representatives of the class breathe using the mucous membrane of the pharynx. The main feature of these animals is longevity. The average age of turtles exceeds the lifespan of any other reptile.

Crocodiles

Animals are one of the most dangerous species of reptiles. The origin of crocodiles is associated with ancient reptiles, the size of which exceeded 15 meters in length. Scientists have been able to find the remains of ancient crocodiles on all continents of the globe. Modern representatives of this class have more conventional sizes. But among reptiles they still remain the largest species.

Almost all the time crocodiles are in the water. Only the ears, nose and eyes of the animal appear on the surface. Crocodiles swim with the help of webbed tails and paws. But at great depths, only single representatives of the class can exist - the comb species. Crocodiles' nests are located on land. In some cases, they also crawl out of the water to warm themselves.

Reptiles have a strong, powerful tail and are also characterized by high speed of movement on land. Therefore, crocodiles are extremely dangerous to humans. A sudden sudden burst can take people by surprise. Alligators are considered the most dangerous representatives of crocodiles.

Chameleons

This type of lizard is known to almost everyone. Reptiles are known for their unique coloration, which serves as a camouflage feature. An animal's skin can change color depending on environmental conditions. Chameleons live in trees. Some people keep these cute creatures at home.

Reptiles are quite finicky to care for. They need a spacious terrarium, which is equipped with special lamps. You will need wood, a small pond, heated floors and excellent ventilation. Chameleons feed on insects. Therefore, the owners will also have to take care of their availability.

Iguanas

Currently, there are more and more lovers of pets - iguanas. This representative of lizards also requires special care. Iguanas must be kept in a special terrarium that can maintain a certain temperature regime. For food, domestic iguanas prefer fresh fruits and vegetables, as well as greens. With good care and optimal living conditions, lizards at home can grow quite large. Maximum iguana weight - 5 kg. It is difficult to keep such a pet at home; it will require a large financial investment, as well as significant labor costs.

Iguanas are among those rare species of reptiles that molt. Most reptiles experience this period in two days, but in iguanas it lasts for several weeks.

Monitor lizards

There are about 70 species of monitor lizards. They live in different territories. The size of the animals is very impressive. Short-tailed monitor lizards have a length of about 20 cm, while other representatives have a much longer length (about 1 meter). The largest monitor lizards are the Komodo species. Their dimensions reach three meters in length, and their weight is 1500 kg. It’s not for nothing that such animals are called modern dinosaurs.

Monitor lizards are covered with large scales. They have strong paws with a tenacious grip and powerful long tail. The animal's tongue is also large in size; at the end it is divided in half. Lizards can only smell with their tongue. The color of animals is dominated by gray and brown shades. Young representatives of the class are often found with spotted or striped scales. Monitor lizards live in regions with warm climates. They are most common in Australia, Africa and southern Asia. Depending on their habitat, monitor lizards are divided into two types. The first of them lives in a desert area with dry trees and shrubs. And the second is located closer to tropical forests and reservoirs. Some representatives of monitor lizards live on tree branches.

Geckos

Unique representatives of reptiles that are able to stick to any surface, even the smoothest. Geckos can climb smooth glass walls, hang from ceilings, and many other interesting things. The lizard is able to stay on the surface with just one paw.

Snakes

These are famous representatives of reptiles. The main difference from other species is the body shape. Snakes have a long body, but do not have paired limbs, eyelids or an external auditory canal. Some of these characteristics are present in individual lizard species, but collectively such characteristics are only observed in snakes.

Zmeinoye the body consists of three elements:

• head;
• body;
• tail.

Some representatives retained rudimentary forms of limbs. A large number of snake species are venomous. They have grooved or channeled teeth that contain venom. This dangerous liquid comes from the animal's salivary glands. All internal organs of a snake differ from standard indicators. They have an oblong shape. Animals do not have a bladder. There is before our eyes cornea, which was formed from fused eyelids. Snakes that are diurnal have a transverse pupil, while nocturnal snakes have a vertical pupil. Because Since animals do not have an auditory canal, they can only hear loud sounds.

Snakes

These are representatives of one of the varieties of snakes. Their main feature is that they are not poisonous. Snakes have bright scales with a large ribbed surface. Animals are common near water bodies. Amphibians and fish serve as food for them. Sometimes snakes manage to catch a bird or small mammal. Such snakes do not kill their prey; they swallow it whole.

If the snake senses danger, it pretends to be dead. And when attacked, a liquid with an extremely unpleasant odor is released from the mouth. Snakes breed on plant soils covered with damp moss or natural debris.

The list of modern reptiles can be continued for a very long time. All representatives of the class have certain similarities characteristic of this type of animal, as well as clear differences. Such animals are of great interest to scientists and hobbyists from all over the world. Their unique features can tell a lot.

The topic of this article is reptiles. Species, origin, habitats, as well as some other facts about them will be presented in it.

The word "reptile" comes from a Latin term meaning "to creep" or "to crawl." This implies the nature of movement of representatives of this class. It should be noted, however, that not all reptiles are animals that can only crawl. There are those who jump well, run, swim and even practically fly, gliding like flying squirrels.

Ancient reptiles

These animals lived long before humans appeared on our planet. Reptiles living on Earth today are only relics (minor remnants) of a very diverse and rich class in the past. We are talking about reptiles that reached their greatest prosperity in (approximately 230-67 million years BC). Ancient reptiles were represented in a huge number of forms. Some of their species lived on land. One can note among them the large predatory Tarbosaurus and the giant herbivorous Brontosaurus. Others, such as ichthyosaurs, lived in water. Still others could fly like birds. The amazing world of reptiles of antiquity has not yet been fully studied. Perhaps in the near future scientists will encounter new discoveries.

In 1988, the remains of reptiles were discovered in Scotland. According to experts, these reptiles lived 340 million years ago. It turned out to be the most ancient species of fossil reptile known today. Their body length was only 20.3 cm.

Origin of ancient reptiles

Ancient reptiles evolved from ancient amphibians. This event became the next stage in the adaptation of vertebrates to life on land. Today, amphibians and reptiles coexist. Amphibians are otherwise called amphibians, and reptiles are called reptiles.

Groups of modern reptiles

Reptiles (modern) include the following groups.

1. Crocodiles. These are large animals with a lizard-like body. There are only 23 species, which include true crocodiles, as well as alligators, caimans and gharials.

2. Beakheads. They are represented by only one species of hatteria called Sphenodon punctatus. These reptiles (a photo of one of them is presented below) resemble in appearance (up to 75 cm) with a massive body, five-fingered limbs and large heads.

3. Scaly. This group of reptiles is the most numerous. It includes 7600 species. These include, for example, lizards, the largest group of modern reptiles. These include: monitor lizards, iguanas, lizards, skinks, agamas, chameleons. Lizards are a specialized species that leads a primarily arboreal lifestyle. Scaly animals also include snakes - legless reptiles, as well as amphisbaenas - creatures with a worm-like body and a short tail, externally resembling the head end. Amphisbaenas are adapted to lead a burrowing lifestyle. They very rarely appear on the surface. These reptiles spend most of their lives underground or in the nests of termites and ants, which amphisbaenas feed on. They usually lack limbs. Representatives belonging to the genus Bipes have only front legs. They can move along earthen passages and tail first. Because of this, they are also called two-year-olds. "Amphisbaena" is translated from Greek as "moving in both directions."

4. Another group - turtles. Their bodies are surrounded from below, from the sides and from above by shells. The carapace includes the abdominal (plastron) and dorsal (carapace) shields, which are connected by a bone bridge or tendon ligament. There are about 300 species of turtles.

Together with mammals and birds, reptiles are combined into one group of higher vertebrates.

Where do reptiles live?

Most reptiles lead a terrestrial lifestyle. These are creatures that prefer open landscapes warmed by the sun, including arid deserts practically devoid of vegetation. However, many turtles and all crocodiles live in rivers, lakes or swamps. Some snakes and some turtles also live permanently in the seas.

Reptile skin, unfortunately, is now used for the production of leather products. It is highly valued, and many reptiles suffer because of it. Their future is in our hands.

Habitats of crocodiles

Crocodiles are common in all tropical countries. Basically, these reptiles are animals that live in deep swamps, lakes and rivers. They usually spend most of the day in the water. Crocodiles come out to the coastal shallows in the morning and also in the late afternoon to bask in the sun. Relatively few of their species are tolerant of salty sea water. The saltwater crocodile swims especially far into the open sea - up to 600 km from the coast.

Habitats of tuataria and lizards

Hatterias today survive only on rocky islands located near New Zealand. A special reserve was created here for their sake.

Lizards are distributed almost throughout the planet, except for cold zones. Some types of mountains rise to the border of eternal snow, for example, in the Himalayas - to an altitude of 5.5 km above sea level. Most lizards lead a terrestrial lifestyle.

However, some of them climb trees or bushes, such as roundheads. Others can live permanently in trees and have the ability to glide. Rock-dwelling agamas and geckos can move along vertical surfaces. Also, some lizards live in the soil. They usually have no eyes and their bodies are elongated. The sea lizard lives near the surf line. She has excellent swimming ability. She spends a lot of time in the water, feeding on seaweed.

Where do snakes and turtles live?

Snakes are common everywhere on Earth, except New Zealand, the polar regions and some oceanic islands. They are all good swimmers, and there are even species that spend almost all or all of their time in the water. These are sea snakes. Their tails are compressed laterally in a paddle-like manner. Due to the transition of snakes to a burrowing lifestyle, some of them have smaller eyes and disappeared under the shields, and their tails have also shortened. These are narrow-mouthed snakes and blind snakes.

Freshwater and land turtles are found on many islands, as well as on all continents except Antarctica. Their habitats are very diverse. These are tropical forests, hot deserts, rivers, lakes and swamps, expanses of the ocean and sea coasts. Sea turtles spend their entire lives in water. They come ashore only to lay eggs.

The largest snakes

The largest modern snakes are anacondas (pictured above) and reticulated pythons. They reach 10 meters in length. In Eastern Colombia, a specimen of anaconda was found, unique in size - 11 m 43 cm. The Brahmin blind beetle is a body length of no more than 12 cm.

Sizes of crocodiles

The largest of the crocodiles are the combed and the Nile. They reach a length of 7 m. 1.2 m for females and 1.5 m for males is the maximum body length of the smooth-fronted caiman, the smallest among other species of crocodiles.

The largest and smallest turtles

The largest of the modern turtles is the leatherback sea turtle. Its length can exceed 2 meters. In Great Britain, on the shore in 1988, the dead body of a male was discovered; it had a width of 2.77 m and a length of 2.91. The musk turtle is the smallest of all species. On average, the length of its carapace is 7.6 cm.

Lizard sizes

Among lizards, Virginia round-toed geckos are considered the smallest. The length of their bodies is only 16 mm (excluding the tail). Without a doubt, the largest lizard is the Komodo dragon (its photo is presented below).

The length of its body reaches three or even more meters. The thin-bodied Salvador monitor lizard, which lives in Papua New Guinea, reaches 4.75 m in length, but about 70% of its length is in the tail.

Reptile body temperature

Like amphibians, reptiles do not have any constant body temperature. Their life activity therefore depends to a large extent on the ambient temperature. For example, in dry and warm weather they are especially active and are often seen at this time. On the contrary, in bad weather and cold they become inactive and rarely leave their shelters. At temperatures close to zero, reptiles fall into torpor. That is why they are few in number in the taiga zone. There are only about 5 species here.

Reptiles can control their body temperature simply by taking shelter from hypothermia or overheating. Hibernation, for example, allows reptiles to avoid the cold, and the heat of the day allows them to be active at night.

Breathing Features

Reptiles (photos of some of them are presented in this article), unlike amphibians, breathe only through their lungs. Their lungs retain a sac-like structure, but reptiles have a much more complex internal structure than amphibians. The inner walls of their lung sacs have a folded cellular structure. They resemble a honeycomb. This significantly increases the respiratory surface of reptiles. Unlike amphibians, reptiles do not force air through their mouths. However, most of them are characterized by breathing of the so-called “suction” type. They exhale and inhale air through the nostrils by constricting and expanding the chest. The act of breathing is carried out using the abdominal and intercostal muscles.

However, in turtles, the ribs are immobile due to the presence of a shell, so the species belonging to them have developed a different method of ventilation than other reptiles. They force air into their lungs by swallowing it or by making pumping movements with their front legs.

Reproduction

Reptiles breed on land. Moreover, unlike amphibians, they have direct development, that is, without a larval stage. Reptiles usually lay large, yolk-rich eggs with shell and amniotic (embryonic) membranes, which protect the embryos from mechanical damage and water loss, and also provide gas exchange and nutrition. By the time of hatching, young reptiles reach significant sizes. These are already miniature copies of adult individuals.

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

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

Reptiles are common to all except . Depending on the species, they can live both on land and in water.

The modern classification identifies the following 4 orders of reptiles:

Order Beakheads

Beakheads ( Rhynchocephalia) - an order of lizard-like reptiles that includes only one living genus, tuatara (tuatara). In turn, this genus ( Sphenodon) includes two types: Sphenodon punctatus And 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. Representatives of the order 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 can be traced back to.

Hatteria grows up to 80 cm in length, from head to tail, and weighs up to 1.3 kg. This animal has a spiny crest along its back, which is especially pronounced in males. Tuatara are also distinguished by the presence of a pronounced parietal eye (third eye). Animals can hear, although there is no external ear and hatteria have unique skeletal features.

Tuatara, like many of New Zealand's endemic animals, are endangered due to loss and introduction of invasive species.

Squad Crocodiles

Saltwater crocodile

Crocodiles ( Crocodylia) - a detachment of large, predatory reptiles, which includes 24 species. This includes: caimans, alligators, real crocodiles, gharials, etc. Crocodiles have powerful jaws with a large number of conical teeth and short paws, with claws, and webbed toes. They have a unique body shape that allows the eyes, ears and nostrils to be above the surface of the water while most of the animal's body is submerged. The tail of crocodiles 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 fossil crocodiles have been discovered that lived for more than 200 million years, in the late. They are the largest and heaviest of modern reptiles. The largest representatives of the order are the Nile crocodile ( Crocodylus niloticus) and saltwater 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-faced caimans ( Paleosuchus) and blunt-snouted crocodiles ( Osteolaemus tetraspis), have a length of about 1.7 m.

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 that live on land and in water (fresh and salt) on all continents except.

The earliest known members of this order existed about 220 million years ago, making 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 live in tropical regions and breed year-round. Some turtles rarely see water, while others spend almost their entire lives in it, be it in 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.

Order Scaly

Anaconda

Scaly ( Squamata) - the most numerous order of reptiles, including lizards, chameleons, moths and snakes. Consisting of over 10,000 species, squamates are also the second largest extant order, after the Perciformes (containing about 41% bony fishes).

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 to swallow relatively large prey.

Squamates come in a variety of sizes, from the 16 mm dwarf gecko ( Sphaerodactylus ariasae) to more than 5 m green anaconda ( Eunectes murinus). The order also includes the now extinct mosasaurs, which reached a body length of about 15 m. Among other reptiles, squamates are most closely related to beaked mosasaurs, which closely resemble lizards.

Reptiles, also known as reptiles, are a class of animals, typically terrestrial and vertebrate. It includes creatures such as turtles, crocodiles, lizards, and snakes. Several centuries ago they were combined with amphibians, and now they are considered close to birds. Many reptiles are so unique that studying this class will be interesting even to a non-professional biologist. What types of reptiles are there? Photos and names, as well as some information about each, posted in our article, will help you figure this out.

Turtles

Perhaps with a shell - the most famous include both land and sea species, they are found in many countries of the world, in addition, they are often kept at home even by those who are not a big fan of the exotic. Turtles appeared two hundred million years ago and are believed to have evolved from primitive cotylosaurs. For a long time, people have liked them - they are practically non-dangerous animals that evoke associations only with wisdom and calmness. Turtles are the only ones of the class that have a shell. Inside it is bone, and outside it is formed by horny tissue from many individual elements connected by plates. Land turtles breathe through the lungs, while aquatic turtles breathe through the mucous membrane of the pharynx. In addition, these animals are unique in that they live longer than any other reptiles. The names of the oldest turtles include species such as the Carolina box turtle, one of the reptiles captured was 130 years old. However, more impressive figures are possible in the wild; these individuals simply did not fall into the hands of researchers.

Chameleons

Perhaps many people, if asked to remember the names of reptiles, will not least mention these lizards. The unusual reptiles live on tree branches and are known for their unique camouflage. Their skin can change color according to their surroundings. It's no surprise that chameleons are often kept indoors. But it is worth considering that these are quite demanding reptiles. Photos and names are not all that you need to study before buying an exotic pet. First you need to figure out the conditions of detention - the chameleon needs a spacious terrarium and special lamps, a small pond and a tree, with excellent ventilation, and you will have to buy insects as food.

Iguanas

When listing the names of reptiles that often become domesticated, one cannot fail to mention iguanas. They have become very popular in recent years, and the number of such pets can be measured in tens of thousands. But you shouldn’t believe the information that keeping such a lizard is as easy as keeping a cat or dog. The iguana is a finicky creature whose existence requires a lot of attention and money. The lizard requires a special terrarium with a special temperature regime, as well as food from fresh vegetables, fruits and herbs. If all conditions are met, the iguana can grow to weigh up to five kilograms! A unique feature of these creatures is molting - in many reptiles it happens quickly, but in them it sometimes takes weeks.

Crocodiles

These animals are perhaps the most dangerous and frightening reptiles. The names may be different - crocodiles, gharials, alligators, caimans, but in any case these are creatures from the same order. They are descended from reptiles measuring over fifteen meters in length and have been known since ancient times. Paleontologists have discovered traces in Europe, North America, India and Africa. Now their sizes are much more modest, but they still remain the largest of the reptiles. Crocodiles spend most of their lives in water, exposing only their eyes, nose and ears. The tail and webbed feet make swimming an easy task, but only the combed variety can swim far out to sea. They build nests on land, and sometimes they just go out to bask. The names of the reptiles of this order are different, but both the alligator and the crocodile have one thing in common - they are dangerous to humans. The reptile has incredible speed and a strong tail, so a sudden lunge can cost an unwary traveler his limbs or even his life.

Snakes

These are another reptile whose names are known to everyone. They differ from other reptiles in their long body shape, the absence of paired limbs, eyelids and the external auditory canal. Individual similar signs can be found in lizards, but all together - only in snakes. Nowadays, three thousand species of them are known to man. The body of a snake consists of three parts - head, body and tail. Some species have preserved hind limbs in rudimentary form. Many of them are poisonous, with channeled or grooved teeth, which contain a dangerous liquid that comes there from All internal organs are elongated in shape, and there is no bladder. The eyes are covered by a transparent cornea, formed from fused eyelids. In diurnal snakes, the pupil is located transversely, while in nocturnal ones it is vertical. Due to the reduced ear, only loud sounds are distinguished.

Snakes

They can be very different, despite the fact that they belong to the same order. For example, snakes are snakes, although some believe they are a separate species. In fact, these reptiles are simply not poisonous. However, they are snakes. They are distinguished by expressive scales with large ribs. Most snakes live near bodies of water and feed on fish or amphibians. Less often they manage to catch a small mammal or bird. It swallows prey alive without killing it. When in danger, reptiles pretend to be dead, and when attacked, they secrete a liquid with an unpleasant odor. To reproduce, snakes look for a pile of plant debris, manure or wet moss.

Monitor lizards

These are very famous reptiles, the names of which are most often associated with the Komodo species. In fact, there are seventy species of them, and they do not live only on certain islands. However, they are all distinguished by their impressive sizes - only the short-tailed ones reach up to twenty centimeters, while all the others can grow up to a meter. But, of course, Komodos are the largest, weighing one and a half centners and three meters long. That is why they were called dragons. Monitor lizards have tenacious and strong paws, a muscular long tail and large scales. Lizards sense odors using a long tongue with a fork at the end. The coloring is most often inexpressive, in gray, sand and brown tones, although young individuals can be striped or spotted. Monitor lizards live in warm countries in South or Africa and in Australia. Based on their habitats, they can be divided into two groups. The first prefers desert areas and dry bushes, while the second stays close to water in the tropical forest. Some monitor lizards like to spend time in trees.

Geckos

These are reptiles whose species names are associated with the unique ability to stick to even the smoothest surfaces. A small gecko can climb up a vertical glass wall or even hang from the ceiling. In order to support its weight, the lizard can hold on with one leg. This feature has surprised people for several millennia - Aristotle tried to unravel the skill of geckos.

Modern science knows the answer - the reptile's fingers have small ridges with thin bristles that help it stay on the surface thanks to the law of interaction between molecules.

Reptiles- typical terrestrial animals and their main method of movement is crawling, reptiles on the ground. The most important structural features and biology of reptiles helped their ancestors leave the water and spread widely across the land. These features primarily include internal fertilization And egg laying, rich in nutrients and covered with a dense protective shell, which facilitates their development on land.

The body of reptiles has protective formations in the form scales, covering them with a continuous cover. The skin is always dry, evaporation through it is impossible, so they can live in dry places. Reptiles breathe exclusively with the help of their lungs, which, compared to the lungs of amphibians, have a more complex structure. Intensive lung breathing became possible thanks to the appearance of a new skeletal section in reptiles - chest. The chest is formed by a number of ribs connected on the dorsal side to the spine, and on the abdominal side to the sternum. The ribs, thanks to special muscles, are mobile and contribute to the expansion of the chest and lungs during inhalation and their collapse at the moment of exhalation.

Changes in the structure of the respiratory system are closely related to changes in blood circulation. Most reptiles have a three-chambered heart and two circuits of blood circulation (as do amphibians). However, the structure of the reptile heart is more complex. In its ventricle there is a septum, which at the moment of contraction of the heart almost completely divides it into the right (venous) and left (arterial) halves.

This structure of the heart and the location of the main vessels, different from that of amphibians, more strongly delineates the venous and arterial flows, therefore, the body of reptiles is supplied with blood that is more saturated with oxygen. The main vessels of the systemic and pulmonary circulation are typical of all terrestrial vertebrates. The main difference between the pulmonary circulation of amphibians and reptiles is that in reptiles the cutaneous arteries and veins have disappeared and the pulmonary circulation includes only pulmonary vessels.

About 8,000 currently existing species of reptiles are known, living on all continents except Antarctica. Modern reptiles are divided into orders: protolizards, scaly, crocodiles And turtles.

Reproduction of reptiles

Fertilization in terrestrial reptiles internal: the male injects sperm into the female’s cloaca; they penetrate the egg cells, where fertilization occurs. The female's body develops eggs, which she lays on land (buries in a hole). The outside of the egg is covered with a dense shell. The egg contains a supply of nutrients, due to which the development of the embryo occurs. The eggs do not produce larvae, as in fish and amphibians, but individuals capable of independent life.

First Lizard Squad

TO proto-lizards refers to "living fossil" - tuateria- the only species that has survived to this day only on small islands near New Zealand. This is a sedentary animal, leading a predominantly nocturnal lifestyle and similar in appearance to a lizard. Hatteria in its structure has features that are similar to reptiles and amphibians: the vertebral bodies are biconcave, with a chord preserved between them.

Otrad scaly

Typical representative scaly - quick lizard. Its appearance indicates that it is a terrestrial animal: the five-fingered limbs do not have swimming membranes, the fingers are armed with claws; the legs are short, and therefore the body, when moving, seems to crawl along the ground, every now and then coming into contact with it - reptiles (hence the name).

Lizards

Although the lizard's legs are short, it can run quickly, quickly escaping from its pursuers into its burrow or climbing a tree. This was the reason for its name - quick. The lizard's head is connected to the cylindrical body using the neck. The neck is poorly developed, but will still give the lizard's head some mobility. Unlike a frog, a lizard can turn its head without turning its whole body. Like all land animals, it has through nostrils, and its eyes have eyelids.

Behind each eye, in a small depression, is the eardrum, connected to the middle and inner ear. From time to time, the lizard sticks out of its mouth a long, thin tongue forked at the end - an organ of touch and taste.

The lizard's body, covered with scales, rests on two pairs of legs. The humerus and femur bones are parallel to the surface of the earth, causing the body to sag and drag along the ground. The ribs are attached to the thoracic vertebrae, forming the rib cage, which protects the heart and lungs from damage.

The digestive, excretory and nervous systems of the lizard are basically similar to the corresponding systems of amphibians.

Respiratory organs - lungs. Their walls have a cellular structure, which significantly increases their surface area. The lizard does not have skin respiration.

The lizard's brain is better developed than that of amphibians. Although it has the same five sections, the forebrain hemispheres are larger in size, and the cerebellum and medulla oblongata are much more massive.

The sand lizard is distributed very widely from the Black Sea to the Arkhangelsk region, from the Baltic Sea to Transbaikalia. In the north, it gives way to a viviparous lizard similar to it, but more adapted to the cold climate. The southern regions are home to many different species of lizards. Lizards live in burrows, which in summer weather they leave in the morning and evening, but no further than 10-20 m from the burrow.

They feed on insects, slugs, and in the south - locusts, caterpillars of butterflies and beetles. Within a day, one lizard can destroy up to 70 insects and plant pests. Therefore, lizards deserve protection as very useful animals.

The lizard's body temperature is not constant (the animal is active only in the warm season); it drops sharply even if a cloud approaches the sun. With a longer drop in temperature, the lizard loses mobility and stops eating. During the winter it hibernates; can tolerate freezing and cooling of the body down to -5°, -7°C, while all the life processes of the animal slow down significantly. Gradual warming returns the lizard to active life.

In addition to the sand lizard and viviparous lizard, there are many other species of lizards. Common in Ukraine and the Caucasus large green lizard: in desert areas - agama lizards with a long flexible and unbreakable tail.

Predatory lizard gray monitor lizard, living in the deserts of Central Asia. Its length is up to 60 cm. The monitor lizard eats arthropods, rodents, eggs of turtles and birds. The largest specimens of monitor lizards discovered by herpetologists (the science that studies reptiles) on the island of Komolo reach 36 cm. In the northern regions, the legless lizard is common - spindle.

Chameleons

Chameleons in appearance they resemble medium-sized lizards, with a helmet-shaped outgrowth on the head and a laterally compressed body. This is a highly specialized animal, adapted to an arboreal lifestyle. His fingers are fused together like pincers, with which he tightly grasps the branches of trees. The long and prehensile tail is also used for climbing. The chameleon has a very unique eye structure. The movements of the left and right eyes are not coordinated and independent of each other, which provides some advantages when catching insects. An interesting feature of the chameleon is its ability to change skin color - a protective device. Chameleons are common in India, Madagascar, Africa, Asia Minor and southern Spain.

Snakes

In addition to lizards, the order Squamate includes snakes. Unlike chameleons, snakes are adapted to crawling on their stomachs and swimming. Due to wave-like movements, the legs gradually completely lost their role as organs of locomotion; only some snakes retained their rudiments (a boa constrictor). Snakes move by bending their legless body. Adaptation to crawling was manifested in the structure of the internal organs of snakes, some of them completely disappeared. Snakes have no bladder and only one lung.

Snakes see poorly. Their eyelids are fused, transparent and cover their eyes like a watch glass.

Among snakes there are non-venomous and poisonous species. The largest non-venomous snake is boa- lives in the tropics. There are boas up to 10 m long. They attack birds and mammals, strangling their prey by squeezing it with their body, and then swallowing it whole. Large boa constrictors that live in tropical forests are also dangerous to humans.

Widespread of non-venomous snakes snakes. The common snake is easily distinguished from poisonous snakes by two orange crescent spots on the head and round pupils of the eyes. It lives near rivers, lakes, ponds, feeding on frogs, and sometimes small fish, swallowing them alive.

Poisonous snakes include viper, cobra, or spectacled snake, rattlesnake and etc.

Viper easily recognized by the long zigzag dark stripe running along the back. In the upper jaw of the viper there are two poisonous teeth with tubules inside. Through these tubules, the poisonous liquid secreted by the salivary glands of the snake enters the wound of the victim, and the victim, for example a mouse or small bird, dies.

By destroying huge numbers of mice and locusts, vipers benefit humans. However, their bites can cause long-term illness and even death in animals and even humans. The venom of such snakes as asian cobra, American rattlesnake.

Wounds formed when a person is bitten by a snake look like two red dots. Painful swelling quickly occurs around them, gradually spreading throughout the body. A person develops drowsiness, cold sweats, nausea, delirium, and in severe cases, death occurs.

If a person is bitten by a poisonous snake, it is necessary to immediately take first aid measures., remove excess poison near the wound with blotting paper, cotton wool or a clean cloth, if possible, disinfect the bite site with a manganese solution, strictly protect the wound from contamination, give the victim strong tea or coffee, and ensure rest. Then take him to the hospital as quickly as possible for immediate administration of anti-snake serum. Where there are poisonous snakes, you should not walk barefoot. Care must be taken when picking berries, protecting your hands from snake bites.

Otrad crocodiles

Crocodiles- these are the largest and most highly organized predatory reptiles, adapted to an aquatic lifestyle, living in tropical countries. Nile crocodile Spends most of its life in water, where it swims beautifully, using a strong, laterally compressed tail, as well as hind limbs that have swimming membranes. The crocodile's eyes and nostrils are elevated, so it only needs to raise its head out of the water a little and it can already see what is happening above the water, and also breathe atmospheric air.

On land, crocodiles are slow to maneuver and, when in danger, rush into the water. They quickly drag their prey into the water. These are various animals that the crocodile lies in wait at watering places. It can also attack humans. Crocodiles hunt mainly at night. During the day they often lie motionless in groups on the shallows.

Turtle Squad

Turtles differ from other reptiles in their well-developed, durable shell. It is formed from bone plates, covered on the outside with horny substance, and consists of two shields: the upper convex and the lower flat. These shields are connected to each other from the sides, and there are large gaps in front and behind the joints. The head and forelimbs are exposed from the front, and the hind limbs from the back. Almost all aquatic turtles are predators, while land turtles are herbivores.

Turtles typically lay hard-shelled eggs on land. Turtles grow slowly, but are among the long-livers (up to 150 years). There are giant turtles (soup turtle up to 1 m long, weight - 450 kg, swamp turtle - up to 2 m and up to 400 kg). They are objects of fishing.

Meat, fat, eggs are used for food, and a variety of horn products are made from the shell. We have one species of turtles - marsh turtle, lives up to 30 years. During the winter it hibernates.