Reptile class. Class Reptiles, or Reptiles (Reptilia) General characteristics of the class Types of reptiles

Amphibians (amphibians). This is a small group of the most primitive terrestrial vertebrates (Fig. 87). Depending on the stage of development, most of them spend part of their lives in water. The ancestors of amphibians were lobe-finned fish that lived in fresh, drying water bodies.

Rice. 87. Amphibians: 1 - newt; 2- spotted salamander; 3 - proteus; 4 - axolotl (ambistoma larva); 5 - pond frog; 6 - pipa; 7 - worm

In the larval stage (tadpoles), amphibians have great resemblance with fish: they retain gill breathing, have fins, a two-chambered heart and one circle of blood circulation. Adult forms are characterized by a three-chambered heart, two circles of blood circulation, two pairs of limbs. The lungs appear, but they are poorly developed, so additional gas exchange occurs through the skin (see Fig. 85). Amphibians live in warm, humid places, especially common in the tropics, where they have suitable climatic conditions.

These are separate animals. They are characterized by external fertilization and development in water. From caviar tailless amphibian, for example, a frog, a tailed larva comes out - a tadpole with long fins and branched gills. As it develops, the forelimbs appear, then the hind limbs, and the tail begins to shorten. Branched gills disappear, gill slits (internal gills) appear. From the anterior part of the digestive tube, lungs are formed, as they develop, the gills disappear. There are corresponding changes in the circulatory, digestive and excretory systems. The tail resolves, and the young frog comes to land. At tailed amphibians gills remain much longer (sometimes all life), the tail does not resolve.

Amphibians feed animal food(worms, mollusks, insects), but the larvae living in the water can be herbivorous.

There are three groups of amphibians: caudate(newt, salamander, ambistoma), tailless(toads, frogs) legless, or worms(fish snake, worm).

Tailed amphibians the most primitive. They live in and near water, and their limbs are usually poorly developed. Some have feathery gills throughout their lives.

Ambystoma larva - axolotl even starts breeding before reaching the adult stage. Salamanders are the most numerous.

Worms- a very small family. They have no limbs, the body is elongated, reminiscent of a worm or a snake.

The most prosperous group tailless amphibians. They have a short body and well developed limbs. During the breeding season, they "sing" - make various sounds (croak).

Reptiles (reptiles). Reptiles are terrestrial vertebrates. They adapted well to life on land and displaced many of their amphibian ancestors. Reptiles have a three-chambered heart. They begin to separate arterial and venous blood due to the appearance incomplete septum in the ventricle of the heart; better than amphibians, developed nervous system: the hemispheres of the brain are much larger (see Fig. 85). The behavior of reptiles is much more complex than that of amphibians. In addition to congenital unconditional, they also form conditioned reflexes. Digestive, excretory and circulatory system open at cloaca- Part of the intestine.

The body of reptiles is covered with scales. It is formed in the thickness of the skin - the epidermis - and protects the body from drying out. Some species shed their scales during molting (snakes, lizards). The lungs of reptiles are much larger and more voluminous than those of amphibians, due to the cellularity.

Reptiles are dioecious animals. Fertilization is internal. The female lays eggs in the sand or in the soil in small depressions, covered with a leathery shell. Even aquatic life egg development takes place on land. Some species are characterized by live birth.

Reptiles reached their peak in mesozoic era, about 100-200 million years ago, so this era is called the era of reptiles. There were a huge number and variety of them: dinosaurs - on land, ichthyosaurs - in water, pterosaurs - in the air. Among them were species of enormous size, as well as rather small forms, the size of a cat. Almost all of them died out about 70 million years ago. The cause of extinction is still not fully understood. There are several hypotheses: sudden abrupt change climate, the fall of a giant meteorite, etc. But all of them do not fully explain this riddle.

Currently, there are four main groups: turtles, snakes, lizards and crocodiles (Fig. 88).

Rice. 88. Reptiles: 1 - steppe gecko; 2 - agama; 3 - eared round head; four - frilled lizard; 5 - gray monitor lizard; 6 - spectacle snake; 7 - rattlesnake; 8 - already

characteristic feature turtles is the presence of a shell, consisting of bone plates and covered with a horny substance. Representatives of this group can live both on land and in water. Giant and elephant turtles(up to 110 cm long) - the largest of those living on land. They are common in the Galopogos Islands. Pacific Ocean, Madagascar, Indian Ocean Islands.

sea ​​turtles much larger (up to 5 m), have flipper-like legs. They live in water all their lives, but they lay their eggs on land.

lizards very varied. This is the most prosperous group. These include chameleons, geckos, iguanas, agamas, roundheads, monitor lizards and true lizards. Most lizards are characterized by an elongated body, a long tail well developed limbs. Some (yellow bellies) have lost limbs, they resemble snakes.

At snake the main feature is a long, limbless body. They are crawling animals. All snakes are predators; they swallow prey whole or strangle it, squeezing it in the rings of their bodies. The poisonous glands (modified salivary glands) open with a duct at the base of the poisonous tooth. Snakes include: viper, gyurza, cobra, python, boa constrictor, as well as snakes - non-poisonous representatives of this group.

crocodiles Of all reptiles, they are closest to mammals. Their heart can be called four-chambered, there is a bony palate, air enters through the nostrils into the back of the mouth. By structure oral cavity and the position of the tongue, they are closer to mammals than to other reptiles. These are rather large tailed animals that live in the water, along the banks of rivers. On land, they move slowly, but they are excellent swimmers. Females lay calcareous-shelled eggs on land in small pits. They are characterized by caring for offspring: the female guards the clutch and takes care of the cubs.

Reptiles live mainly in warm climates: tropics, subtropics, wet and dry places: deserts, swamps, forests. Their food is also varied: plants, insects, worms, mollusks, and large individuals eat birds and mammals. All reptiles swallow their food whole. Many species feeding on pests Agriculture(insects, rodents) are of great benefit to humans. The venom of snakes is used in the preparation of many medicines. Shoes, handbags are made from the skin of snakes and crocodiles, which used to lead to mass extermination animals. Currently, many species are under protection, they are grown on farms and in nurseries.

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§ 62. Chordates. Fish§ 64. Birds

Snakes are unusual appearance and behavior, attracting the enduring interest of scientists and admirers of reptiles. The appearance of these reptiles on the planet is attributed 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 originated in Africa more than 200 million years ago, subsequently spreading throughout the world, except for Antarctica.

Animal habitats are tropical areas, forests, steppes, mountain slopes and foothills. Reptiles can live in water, on land and trees. sea ​​snakes went into the deep waters of the ocean, breeding far from coastal zones. also inhabit freshwater lakes and rivers. Species diversity There are about 3 thousand snakes, which are combined into 23 families.

General Characteristics of Scaled Reptiles

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

Some species can reach 12 meters in length. The smallest snakes are only 8 cm. Predatory individuals feed on insects, frogs, fish, bird eggs and small mammals. Certain types capable of swallowing prey several times larger than reptiles in size.

The color of the skin of reptiles is varied and often matches the color scheme of the natural environment. environment. At first sight bright colors reliably hide reptiles in tropical forests, among lush greenery.

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

The duality of the image in ancient mythology

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

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

Among the huge variety of reptiles, snakes were a symbol of healing. The snakes were called the snake of Aesculapius and revered in Rome and. Symbol modern medicine depicted as a bowl with medicine entwined with a snake.

Already

In Antiquity, the reptile was a sacred animal to the goddess Athena. In Egypt, the image of the goddess Isis was represented as half woman, half 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

Chinese culture is filled with ancient legends and traditions related to snakes. In most tales, reptiles embody negative symbols and evil. lore Far East do not distinguish between the images of dragons and snakes.

Dragons acted as guardians of the temples, guarding esoteric knowledge and treasures. There is an opinion that represents a snake closed 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. Thanks to the ability to glide without the help of limbs, reptiles were considered an all-pervading creature, able to overcome any obstacles.

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

The embodiment of the image in Christianity

The image of this reptile in Christianity is considered dually, combining wisdom and the chthonic symbol of the devil. The personification of the fall into sin and everything dark that must be overcome by man. The animal wrapping around 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, personified 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 bad guys"serpent's heart", implying the malice and deceitfulness of the images.

Greek legends represent the snake, 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. Often the symbol was associated with fertility, male and female principles, home. Many magical texts contain an appeal to these animals as intermediaries between the worlds.

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

Turtles

Perhaps with a shell - the most famous include both land and sea ​​views, 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, it is believed that they evolved from primitive cotylosaurs. For a long time people liked them - they are practically not 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 they breathe with lungs, and water - with the help of 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 tortoise, one of the reptiles captured was 130 years old. However, in wild nature more impressive figures are possible, but these individuals simply did not fall into the hands of researchers.

Chameleons

Perhaps many people, if they are asked to remember the names of reptiles, will not least say about these lizards. Unusual reptiles live on the branches of trees and are known for their unique camouflage. Their skin can change color according to their surroundings. Not surprisingly, chameleons are often kept at home. But it should be borne in mind 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 deal with the conditions of detention - the chameleon needs a spacious terrarium and special lamps, a small pond and a tree, with excellent ventilation, and insects will have to be bought as food.

iguanas

Listing the names of reptiles that often become domesticated, one cannot fail to mention iguanas. It has become quite popular in last years, and the number of such pets can be measured in tens of thousands. But do not believe the information that keeping such a lizard is as easy as keeping a cat or a dog. The iguana is a finicky creature whose existence requires a lot of attention and Money. A lizard needs a special terrarium with a special temperature regime, as well as food from fresh vegetables, fruits and herbs. If all conditions are met, an iguana can grow up to five kilograms in weight! A unique feature of these creatures is molting - for many reptiles it happens quickly, and for 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 originated from reptiles over fifteen meters in length and have been known since ancient times. Paleontologists have discovered footprints in Europe, North America, India and Africa. Now their sizes are much more modest, but they still remain the largest of the reptiles. Most Crocodiles spend their lives in water, sticking out only their eyes, nose and ears. Webbed tail and paws make swimming easy task, but only a combed variety can swim far into the sea. On land, they build nests, and sometimes they just get 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 rush can cost the unwary traveler limbs or even life.

snakes

This is another reptile whose names are known to everyone. They differ from other reptiles in their long body shape, lack of paired limbs, eyelids, and external auditory meatus. Separate similar signs can be found in lizards, but all together - only in snakes. Now man knows their three thousand species. The body of a snake consists of three parts - head, body and tail. In some species, hind limbs have been preserved in rudimentary form. Many of them are poisonous, with channeled or grooved teeth, which contain a dangerous fluid that comes there from All internal organs are elongated, and bladder missing. The eyes are covered with a transparent cornea, formed from fused eyelids. In snakes leading a daytime lifestyle, the pupil is located transversely, while in nocturnal snakes 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 detachment. For example, snakes are snakes, although some believe that this is 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 water bodies and feed on fish or amphibians. Rarely do they catch small mammal or a bird. Already swallows prey alive without killing it. In case of danger, reptiles pretend to be dead, and when attacked, they secrete a liquid with bad smell. For reproduction, snakes look for a pile of plant debris, manure or wet moss.

monitor lizards

These are very famous reptiles, whose names are most often associated with the Komodo variety. In fact, there are seventy species of them, and they do not only live on certain islands. However, they all differ in impressive size - only short-tailed ones reach up to twenty centimeters, and all others can grow up to a meter. But, of course, Komodo are the largest, with a weight of one and a half centners and a length of three meters. That is why they are called dragons. Monitor lizards have tenacious and strong paws, muscular long tail and large scales. With a long tongue with a bifurcation at the end, lizards smell. The coloration is most often inexpressive, in gray, sandy and brown tones, although juveniles may be striped or spotted. Monitor lizards live in warm countries South or Africa and Australia. According to their habitats, they can be divided into two groups. The first prefers desert terrain and dry bushes, while the second keeps closer to the water in tropical forest. Some monitor lizards like to spend time in trees.

geckos

These are reptiles whose species names are associated with unique ability 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 foot. This feature has been surprising 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 due to the law of interaction between molecules.

The descendants of extinct dinosaurs are numerous reptiles. The list of reptiles includes about ten thousand species. All of them breathe with lungs, and their skin is covered with horny scales that protect it from drying out. Only on the territory of our country there are 72 species of reptiles.

The list of reptiles includes about ten thousand species.

Class characteristic

The reptile class includes a certain group of cold-blooded animals and has a number of anatomical features. The limbs are located on both sides and widely spaced. During movement, the reptile's body drags along the ground, which does not prevent it from remaining fast and agile at the moment of danger or hunting.

In prehistoric times, this species of fauna lived in the water. In the course of evolution, they moved to terrestrial existence thanks to cellular light, dry integuments of the body and internal fertilization. In the process of growth, the animal periodically sheds.

With fish and amphibians, they are united by the body's ability to regulate body temperature according to environmental conditions. AT winter time years they lose activity and fall into hibernation. In southern latitudes with a hot climate, many of them lead night image life. The dense horny cover and the absence of glands in the epidermis prevent the loss of moisture.

Distribution area

Reptiles are common on all continents except Antarctica. Their populations are especially numerous in tropical and subtropical regions.

The most viable species live on the territory of the Russian Federation. The list of names of reptiles inhabiting almost all regions of our country is quite extensive. It includes:

1. - Far Eastern, Mediterranean, leathery, Caspian, European marsh, big-headed.
2. lizards- gray and Caspian gecko, motley and eared roundhead.
3. snakes- vipers, snakes, suckers and yellowbellies.

Reptiles include lizards, snakes, turtles

All members of this class living in temperate climate, they do not differ large size and prefer small areas for living, as they are incapable of long-distance migrations. They are characterized by high fertility. Females lay dozens of eggs. The density of livestock per hectare can reach one hundred and twenty individuals. Features of nutrition play an important role in the biological indication of nature.

Reproduction features

Reptiles breed on the land surface. Even those who spend most of their lives in the water leave their usual habitat. mating season accompanied by increased activity and fights of males. This is especially common in lizards and turtles.

The bulk of reptiles are egg-laying reptiles. In some species, the egg remains in the oviduct until the baby is fully mature. Such animals are ovoviviparous representatives of the fauna.

Reptiles are naturally endowed with a high ability to survive and preserve the species.

Description of individual species

Reptiles are naturally endowed with a high ability to survive and preserve the species. In the wild, there are both herbivorous and predatory reptiles. The list of titles includes:

• turtles;
• crocodiles;
• lizards;
• snake.

Turtles number about three hundred species. Distributed throughout the world. These harmless animals are often kept as pets. They are among the longest living reptiles. Under favorable conditions, they live up to two hundred and fifty years.

A strong shell protects them from predators, and body weight and size depend on belonging to a particular genus and habitat. Sea turtles can weigh up to a ton and have impressive dimensions. Among land species there are tiny specimens weighing 125 grams and a shell length of 10 centimeters.

The head of the animal is small, which makes it possible in case of danger to quickly remove it under the shell. The reptile has four limbs. The paws of terrestrial animals are adapted for digging the soil, marine life they turned into flippers.

crocodiles- the most dangerous reptiles. The names of some species correspond to their habitat. The most famous of them:

• marine or combed;
• Cuban;
• Mississippian;
• Philippine;
• Chinese;
• Paraguayan.

Crocodiles are divided into families of gharials, caimans and alligators. They differ from each other in the shape of the jaws and body size.

lizards- quick representatives of the fauna. Most of them are small in size and have a high regenerative capacity. They inhabit different parts of the world, are well adapted to different climatic latitudes.

The main part of the lizards is small and has a high regenerative capacity.

Most big representative kind of lizards komodo dragon . It is named after the island of the same name on which it lives. Outwardly, it resembles a cross between a dragon and a crocodile. They create a deceptive impression with their sluggishness. However, they are excellent runners and swimmers.

Snakes are included in the list of animal reptiles that are devoid of limbs. Due to the elongated shape of the body, the internal organs acquired an identical structure. More than three hundred pairs of ribs located throughout the body help to make flexible movements. The triangular head allows the snake to swallow its prey whole.

In nature, there are a huge number of different snakes. Most of them are poisonous. The poison of some is able to kill within a few minutes. Scientists have long learned to use snake venom as medicines and antidotes.

Snakes lacking venom glands include common snakes and pythons. The most large snake in the world lives on the banks of the Amazon and is called the anaconda. Kills the victim with the help of powerful muscles, wrapping rings around it.

Due to the pressure of water, sea snakes are deprived of a rounded shape and resemble a wriggling ribbon. They are very dangerous to humans, as they produce a highly toxic poison. Once on land, they die within a few hours. Settle in the mouths of rivers flowing into the sea. They rarely swim far from the shore.

Difference from amphibians

Compared to amphibians, reptiles are better adapted to living on land. Their muscles are well differentiated. This explains their ability to make quick and varied movements.

The digestive system is longer. Jaws equipped sharp teeth helping to chew even the toughest food. The blood supply is mixed, in which arterial blood predominates. Therefore, they have a higher metabolic rate.

Compared to amphibians, reptiles are better adapted to life on land.

The size of the brain relative to the body is larger than that of amphibians. Features of behavior and sense organs are perfectly adapted to life on the surface of the earth.

Unique reptiles

Among the most interesting and rare reptiles, there are those who have unlike other species anatomical features. The most remarkable representative unique fauna is Tuatara. It lives only in one place - New Zealand. At resemblance with a lizard does not belong to the genus of these reptiles. Internal organs similar to snakes.

With an outward resemblance to a lizard, the hatteria does not belong to the genus of these reptiles.

Unlike other animals, it has three eyes, and an additional organ of vision is located in the back of the head. Possessing slow breathing, she is able not to breathe for a minute. The length of the body is half a meter, the weight is about one kilogram.

it nocturnal predator. It feeds mainly on small animals, crawling and flying insects. The maximum life span is 100 years.

The unique features of reptiles are of interest to biologists and lovers of these animals. Some species are not fully understood due to their secretive lifestyle and remote habitats. Even the most dangerous predators for humans contribute to the ecological balance of the planet and need protection from extermination.

Reptiles or reptiles are the oldest class of true vertebrates that have settled on land.

Reptiles include different kinds snakes, crocodiles, turtles and lizards.

They were the largest dinosaurs that dominated the Earth 150 million years ago.

Animals are direct ancestors despite the fact that they now live in swamps - some of them were able to fly, and elongated scales eventually turned into feathers.

Description

The name of the class comes from the word to crawl - to crawl, dragging the stomach along the ground. This is true - reptiles do not have limbs at all, in the rest they are located almost at the level of the spine.

Appearance

Unlike amphibians, which are wet and slippery to the touch, reptiles always have dry skin. This helps to retain moisture inside the body, which is especially important for the inhabitants of arid regions.

Reptiles description

Reptiles are endowed with perfectly protected skin from external influences, including from the scorching sun, the skin is covered with scales. Snakes and lizards periodically molt, that is, shed the skin from which they grew, and then acquire new skin.

Almost all animals of the reptile class are colored in accordance with colors environment, so as not to become easy prey for predators, and so as not to be too visible to their victims.

The chameleon is famous for the fact that it can change color depending on many factors - temperature, humidity, thirst, emotional state.

Food

Animals cannot chew food, they can only tear it into pieces. And snakes generally swallow their prey whole, and often the size of the victim exceeds the size of the snake itself.

Reptiles of our planet

A snake can do such a trick thanks to its ability to open its mouth very wide, its stomach is able to stretch to incredible sizes.

Habitat

Most reptiles live in warm regions - in deserts, semi-deserts and tropical rainforests.

They can also be found in cooler natural areas, in hardwood and mixed forests, but much less frequently.

Unusual reptiles

This is explained by the fact that the body temperature of reptiles practically does not differ from the ambient temperature. Therefore, reptiles living in cold regions have to warm up in the sun for a long time. AT warm time years they lead an active life, and in the cold they hibernate.

reproduction

Reptiles lay their eggs in a hard protective shell and leave them in nests or simply bury them in the sand.

All of them except, don't care about future fate their cubs - hatched from eggs, they are already leading independent life. Some species of lizards and snakes are viviparous.

Red Book

Almost all types of reptiles are listed in the Red Book, some of them are on the verge of extinction.

Reptiles snakes photo

On the part of the governments of some countries, measures are being taken, special farms are being created for the reproduction of one or another species that is about to disappear. But this will not help much, since many species of reptiles have already been so exterminated by man that it is not possible to restore them.

Lifespan

Due to the fact that all processes in the body of reptiles occur very slowly, their life expectancy is very high. Crocodiles live about 70 years, and turtles - more than 150.

1. Reptiles are an important link the food chain– they feed on insects and small rodents and thus regulate their numbers. The reptiles themselves serve as food for some.
2. Snake venom is the basis of many medicines.
3. Expensive shoes and accessories are made from crocodile and snake skin, and jewelry is made from shells.
4. For this, reptiles are grown on special farms so as not to reduce their numbers in the wild.
5. The meat and eggs of crocodiles and turtles are eaten by residents of many tropical countries.