Post on the evolution of reptiles. Evolutionary development of reptiles. Excerpt from the Origin of Reptiles

). They lived near water bodies and were closely related to them, since they multiplied only in water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

Carboniferous period

The remains of the most ancient reptiles are known from the Upper Carboniferous (about 300 million years ago). It is believed that isolation from amphibian ancestors should have begun, apparently, in the Middle Carboniferous (320 million years), when from anthracosaurs like Diplovertebron, the forms were isolated, apparently better adapted to the terrestrial way of life. From such forms a new branch arises - the Seymuryomorphs ( Seymouriomorpha), the remains of which were found in the Upper Carboniferous - Middle Permian. Some paleontologists classify these animals as amphibians.

Permian period

From the upper Permian deposits North America, Western Europe, Russia and China are known for the remains of cotylosaurs ( Cotylosauria). According to a number of signs, they are still very close to stegocephals. Their skull was in the form of a solid bone box with holes only for the eyes, nostrils and the parietal organ, cervical spine the spine was poorly formed (although there is a structure characteristic of modern reptiles of the first two vertebrae - atlanta and epistrophy), the sacrum had from 2 to 5 vertebrae; in the shoulder girdle, kleitrum, a skin bone characteristic of fish, was preserved; the limbs were short and widely spaced.

Further evolution of reptiles was conditioned by their variability due to the influence of various living conditions that they encountered during reproduction and dispersal. Most of the groups have become more mobile; their skeleton has become lighter, but at the same time and stronger. Reptiles used a more varied diet than amphibians. The technique of obtaining it changed. In this regard, the structure of the limbs, axial skeleton and skull underwent significant changes. The majority of the limbs became longer, the pelvis, gaining stability, was attached to two or more sacral vertebrae. In the shoulder girdle disappeared "fish" bone cleithrum. The solid carapace of the skull underwent partial reduction. In connection with the more differentiated muscles of the jaw apparatus, pits and bony bridges dividing them - arcs, which served to attach a complex system of muscles, appeared in the temporal region of the skull.

Synapsids

The main ancestral group that gave all the variety of modern and fossil reptiles were cotylosaurs, but the further development of reptiles went in different ways.

Diapsids

The next group to separate from the cotylosaurs were diapsid ( Diapsida). Their skull has two temporal cavities, located above and below the postorbital bone. Diapsids at the end of the Paleozoic (Permian) gave extremely wide adaptive radiation to systematic groups and species, which are found both among extinct forms and among today's reptiles. Among the diapsids, two main groups of Lepidosauromorphs ( Lepidosauromorpha) and Archosauromorphs ( Archosauromorpha). The most primitive diapsids from the Lepidosaur group are the Eosuchia order ( Eosuchia) - were the ancestors of the Beakheads order, from which only one genus has survived - the tuatara.

At the end of the Permian, scaly ( Squamata), which became numerous in the Cretaceous. Towards the end of the Cretaceous period, snakes evolved from lizards.

Origin of archosaurs

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Literature

• N.P. Naumov, N.N. Kartashev Part 2. Reptiles, birds, mammals // Zoology of vertebrates. - M.: graduate School, 1979 .-- S. 272.

View this template Evolutionary processes Evolution factors Population genetics Origin of life Historical concepts Contemporary theories Evolution of taxa

Excerpt from the Origin of Reptiles

I remember how just a few weeks before that terrible day, my grandfather and I sat in the garden and "listened" to the sunset. For some reason, grandfather was quiet and sad, but this sadness was very warm and light, and even some kind of deeply kind ... Now I understand that he already knew then that he would be leaving very soon ... But, unfortunately, not I knew that.
- Someday, in many, many years ... when I am no longer by your side, you will also look at the sunset, listen to the trees ... and maybe sometimes remember your old grandfather, - grandfather's voice murmured in a quiet stream. - Life is very dear and beautiful, baby, even if at times it will seem cruel and unfair to you ... Whatever happens to you, remember: you have the most important thing - your honor and yours human dignity that no one can take away from you, and no one can drop them, except you ... Keep it, baby, and do not let anyone break you, and everything else in life is replenished ...
He rocked me like little child, in their dry and always warm hands. And it was so surprisingly calm that I was afraid to breathe, so as not to accidentally frighten off this wonderful moment when the soul warms up and rests, when the whole world seems huge and so unusually kind ... when suddenly the meaning of his words reached me !!!
I jumped up like a disheveled chicken, panting with indignation, and, as luck would have it, not finding in my "rebellious" head such necessary words at this moment. It was so offensive and completely unfair! .. Why, on such a wonderful evening, he suddenly needed to start talking about the sadly inevitable that (even I already understood) sooner or later would have to happen ?! My heart did not want to listen to this and did not want to accept such "horror". And it was completely natural - after all, all of us, even children, do not want to admit this sad fact to ourselves so much that we pretend that it will never happen. Maybe with someone, somewhere, sometime, but not with us ... and never ...
Naturally, all the charm of our wonderful evening disappeared somewhere and I no longer wanted to dream of anything else. Life again let me understand that no matter how hard we tried, not so many of us are really given the right to have positions in this world ... The death of my grandfather really turned my whole life in the literal sense of the word. He died in my childish arms when I was only six years old. It happened in an early sunny morning, when everything around seemed so happy, affectionate and kind. In the garden, the first awakened birds happily echoed, cheerfully passing each other latest news... The rosy-cheeked dawn, softened by the last morning sleep, was just opening its eyes, washed by the morning dew. The air was fragrant with surprisingly "tasty" smells of summer riot of flowers.
Life was so pure and beautiful! .. And it was in no way possible to imagine that such a fabulously wonderful world could suddenly ruthlessly burst into trouble. She just had no right to do it !!! But, it is not in vain that it is said that trouble always comes uninvited, and never asks permission to enter. So she came to us this morning without knocking, and playfully destroyed my seemingly well protected, tender and sunny children's world, leaving only unbearable pain and a terrible, cold emptiness of the first loss in my life ...
This morning my grandfather and I, as usual, were going to go to our beloved forest for strawberries, which I loved very much. I was quietly waiting for him on the street, when suddenly it seemed to me that a piercing icy wind blew from somewhere and a huge black shadow fell to the ground. It became very scary and lonely ... There was no one in the house except my grandfather at that moment, and I decided to go and see if something had happened to him.
Grandpa was lying on his bed very pale and for some reason I immediately realized that he was dying. I rushed to him, hugged him and began to shake, trying by all means to bring him back. Then she began to scream and call for help. It was very strange - for some reason no one heard me and did not come, although I knew that everyone was somewhere nearby and should hear me for sure. I didn’t understand then that it was my soul screaming ...
I had an eerie feeling that time had stopped and that we were both outside it at that moment. It was as if someone had placed both of us in a glass ball, in which there was neither life, nor time ... And then I felt all the hairs on my head stand on end. I will never forget this sensation, even if I live a hundred years! .. I saw a transparent luminous essence that left my grandfather's body and, swam up to me, began to gently pour into me ... At first I was very scared, but immediately felt a calming warmth and for some reason I realized that nothing bad could happen to me. The essence flowed in a luminous stream, easily and softly pouring into me, and became smaller and smaller, as if “melting” a little ... And I felt my body huge, vibrating and unusually light, almost “flying”.
It was a moment of merging with something extraordinarily significant, all-encompassing, something incredibly important to me. And then there was a terrible, all-consuming pain of loss ... That surged in a black wave, sweeping away any attempt to resist it on its way ... I cried so much during the funeral that my parents began to fear that I would get sick. The pain completely took possession of my childish heart and did not want to let go. The world seemed frighteningly cold and empty ... I could not come to terms with the fact that my grandfather would be buried now and I would never see him again! .. I was angry with him for leaving me, and angry with myself that I could not to rescue. Life was cruel and unfair. And I hated her for having to bury him. This is probably why they were the first and last funeral, at which I was present for the rest of my life ...

After that, for a very long time I could not come to my senses, became withdrawn, and spent a lot of time alone, which upset all my relatives to the depths of my soul. But, little by little, life took its toll. And, after some time, I slowly began to get out of that deeply isolated state into which I plunged myself, and it turned out to be very, very difficult to get out of it ... My patient and loving parents tried to help me as best they could. But with all their efforts, they did not know that in reality I was no longer alone - that after all my experiences, an even more unusual and fantasy world than the one I've lived in for a while. A world that surpassed in its beauty any imaginary fantasies, and which (again!) My grandfather gave me with his extraordinary essence. It was even more amazing than everything that happened to me before. Only for some reason this time I no longer wanted to share this with anyone ...
Days went by. In my Everyday life I was an absolutely normal six-year-old child who had his own joys and sorrows, desires and sorrows and such unrealizable, iridescent childhood dreams ... I chased pigeons, loved to walk with my parents to the river, played children's badminton with friends, helped, according to my abilities , to my mother and grandmother in the garden, read my favorite books, learned to play the piano. In other words, she lived the most normal, ordinary life of all small children. Only the trouble was that by that time I already had two Lives ... I seemed to live in two completely different worlds: the first - it was our ordinary world, in which we all live every day, and the second - it was my own "hidden" world, in which only my soul lived. It became more and more difficult for me to understand why what was happening to me did not happen to any of my friends?
I began to notice more often that the more I shared my “incredible” stories with someone from my environment, the more often I felt strange alienation and childish wariness on their part. It hurt and made me feel very sad. Children are curious, but they don't like the incomprehensible. They always try to get to the bottom of what is happening with their childish mind as quickly as possible, acting on the principle: “what is this and what is it with?” ... And if they cannot understand this, it becomes “alien” to their everyday environment and is very quickly disappears into oblivion. This is how I started to become a little bit "alien" ...

The appearance of reptiles on Earth - greatest event in evolution.

It had tremendous consequences for the whole of nature. The origin of reptiles is one of the important questions in the theory of evolution, the process that resulted in the appearance of the first animals belonging to the Reptilia class. The first terrestrial vertebrates appeared in the Devonian (more than 300 million years ago). These were shell-headed amphibians - stegocephals. They were closely related to water bodies, since they multiplied only in water, lived near water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

Carboniferous period

Seymuria

All reptiles can be divided into three groups:

1) anapsids - with a solid cranial shell (cotilosaurs and turtles);

2) synapsids - with one zygomatic arch (bestial, plesiosaurs and possibly ichthyosaurs) and

3) diapsids - with two arches (all other reptiles).

Anapsid group is the oldest branch of reptiles with many common features with fossil stegocephals, since not only many of their early forms (cotylosaurs), but even some modern ones (some turtles) have a continuous cranial shell. Turtles are the only living representatives of this ancient group of reptiles. They separated, apparently, directly from the cotylosaurs. Already in the Triassic, this ancient group was fully formed and, thanks to its extreme specialization, has survived to the present time, almost unchanged, although in the process of evolution some groups of turtles several times passed from a terrestrial lifestyle to an aquatic one, in connection with which they almost lost their bony shields then acquired them again.

Synapsid group. Marine fossils of reptiles - ichthyosaurs and plesiosaurs - separated from the group of cotylosaurs. Plesiosauria, which are synaptosaurs, were marine reptiles. They had a wide, barrel-shaped, flattened body, two pairs of powerful limbs modified into swimming fins, a very long neck ending in a small head, and a short tail. The skin was bare. Numerous sharp teeth sat in separate cells. The sizes of these animals varied over a very wide range: some species were only half a meter in length, but there were also giants, reaching 15 m. While the plesiosaurs, having adapted to aquatic life, still retained the appearance of terrestrial animals, the ichthyosauria (Ichthyosauria), belonging to the ichthyoptergia, acquired similarities with fish and dolphins. The body of the ichthyosaurs was fusiform, the neck was not pronounced, the head was elongated, the tail had a large fin, the limbs were in the form of short flippers, and the hind ones were much smaller than the front ones. The skin was bare, numerous sharp teeth (adapted to feeding on fish) sat in a common furrow, there was only one zygomatic arch, but of an extremely peculiar structure. The sizes varied from 1 to 13 m.

Diapsid group includes two subclasses: lepidosaurs and archosaurs. The earliest (Upper Permian) and most primitive group of lepidosaurs is the order of eosuchia (Eosuchia). They are still very poorly studied, lounginia is better known than others - a small reptile resembling a lizard in physique, with relatively weak limbs that had the usual reptilian structure. Its primitive features are expressed mainly in the structure of the skull, the teeth are located both on the jaws and on the palate.

Now there are about 7000 species of reptiles, that is, almost three times more than modern amphibians. The living reptiles are divided into 4 groups:

· Scaly;

· Turtles;

· Crocodiles;

· Beakheads.

The most numerous order of scaly (Squamata), including about 6,500 species, is the only currently thriving group of reptiles, widespread in the globe and constituting the bulk of the reptiles of our fauna. This order includes lizards, chameleons, amphisbens and snakes.

Much less turtles (Chelonia) - about 230 species, represented in the animal kingdom of our country by several species. This is a very ancient group of reptiles that have survived to this day thanks to a kind of protective device - the shell in which their body is chained.

Crocodiles (Crocodylia), of which there are about 20 known species, inhabit the continental and coastal water bodies of the tropics. They are direct descendants of the ancient highly organized reptiles of the Mesozoic.

The only species of modern beak-headed (Rhynchocephalia) - the tuatara has many extremely primitive features and has survived only in New Zealand and the adjacent small islands.

Reptiles lost their dominant position on the planet mainly due to competition with birds and mammals against the background of a general cooling, which is confirmed by the current ratio of the number of species of different classes of terrestrial vertebrates. If the share of amphibians and reptiles, most dependent on the temperature of the environment, on a global scale is quite high (10.5 and 29.7%), then in the CIS, where the area of ​​warm regions is relatively small, they amount to only 2.6 and 11.0% ...

Reptiles, or reptiles, of Belarus are the northern "outpost" of this diverse class of vertebrates. Of the more than 6500 species of reptiles that now live on our planet, only 7 are represented in the republic.

In Belarus, which does not differ in the warmth of the climate, there are only 1.8% of reptiles and 3.2% of amphibians. It is important to note that the decrease in the proportion of amphibians and reptiles in the fauna of northern latitudes occurs against the background of a decrease in the total number of species of terrestrial vertebrates. Moreover, out of four orders of modern reptiles, only two live in the CIS and Belarus (turtles and scaly ones).

The Cretaceous period was marked by the collapse of the reptiles, the almost complete extinction of the dinosaurs. This phenomenon presents a mystery to science: how a huge, prosperous, occupying everything ecological niches the army of reptiles, which had representatives from the smallest creatures to unimaginable giants, so suddenly died out, leaving only relatively small animals?

It is these groups at the beginning of modern Cenozoic era took a dominant position in the animal kingdom. And among the reptiles of 16-17 orders that existed in the heyday, only 4 survived. Of these, one is represented by the only primitive species - tuberculosis, preserved only on two dozen islands near New Zealand.

Two other orders - turtles and crocodiles - unite a relatively small number of species - about 200 and 23, respectively. And only one order - scaly ones, which includes lizards and snakes, can be assessed as thriving in the current evolutionary era. It is a large and varied group of over 6,000 species.

Reptiles are distributed throughout the globe, except for Antarctica, but extremely unevenly. If in the tropics their fauna is the most diverse (in some regions, 150-200 species live), then only a few species penetrate into high latitudes (in Western Europe, only 12).

). They lived near water bodies and were closely related to them, since they multiplied only in water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

Carboniferous period

The remains of the most ancient reptiles are known from the Upper Carboniferous (about 300 million years ago). It is believed that isolation from amphibian ancestors should have begun, apparently, in the Middle Carboniferous (320 million years), when from anthracosaurs like Diplovertebron, the forms were isolated, apparently better adapted to the terrestrial way of life. From such forms a new branch arises - the Seymuryomorphs ( Seymouriomorpha), the remains of which were found in the Upper Carboniferous - Middle Permian. Some paleontologists classify these animals as amphibians.

Permian period

Remains of cotylosaurs ( Cotylosauria). According to a number of signs, they are still very close to stegocephals. Their skull was in the form of a solid bone box with holes only for the eyes, nostrils and the parietal organ, the cervical spine was poorly shaped (although there is a structure characteristic of modern reptiles of the first two vertebrae - atlanta and epistrophy), the sacrum had from 2 to 5 vertebrae; in the shoulder girdle, kleitrum, a skin bone characteristic of fish, was preserved; the limbs were short and widely spaced.

Further evolution of reptiles was conditioned by their variability due to the influence of various living conditions that they encountered during reproduction and dispersal. Most of the groups have become more mobile; their skeleton has become lighter, but at the same time and stronger. Reptiles used a more varied diet than amphibians. The technique of obtaining it changed. In this regard, the structure of the limbs, axial skeleton and skull underwent significant changes. The majority of the limbs became longer, the pelvis, gaining stability, was attached to two or more sacral vertebrae. In the shoulder girdle disappeared "fish" bone cleithrum. The solid carapace of the skull underwent partial reduction. In connection with the more differentiated muscles of the jaw apparatus, pits and bony bridges dividing them - arcs, which served to attach a complex system of muscles, appeared in the temporal region of the skull.

Synapsids

The main ancestral group that gave all the variety of modern and fossil reptiles were cotylosaurs, but the further development of reptiles went in different ways.

Diapsids

The next group to separate from the cotylosaurs were diapsid ( Diapsida). Their skull has two temporal cavities, located above and below the postorbital bone. Diapsids at the end of the Paleozoic (Permian) gave extremely wide adaptive radiation to systematic groups and species, which are found both among extinct forms and among today's reptiles. Among the diapsids, two main groups of Lepidosauromorphs ( Lepidosauromorpha) and Archosauromorphs ( Archosauromorpha). The most primitive diapsids from the Lepidosaur group are the Eosuchia order ( Eosuchia) - were the ancestors of the Beakheads order, from which only one genus has survived - the tuatara.

At the end of the Permian, scaly ( Squamata), which became numerous in the Cretaceous. Towards the end of the Cretaceous period, snakes evolved from lizards.

Origin of archosaurs

see also

Write a review on the article "The Origin of Reptiles"

Notes (edit)

Literature

• N.P. Naumov, N.N. Kartashev Part 2. Reptiles, birds, mammals // Zoology of vertebrates. - M .: Higher school, 1979 .-- S. 272.

Evolutionary processes Evolution factors Population genetics Origin of life Historical concepts Contemporary theories Evolution of taxa

Excerpt from the Origin of Reptiles

He wanted to say something else, but at that time Prince Vasily got up with his daughter, and two young men stood up to give them a way.
“Excuse me, my dear Viscount,” said Prince Vasily to the Frenchman, gently pulling him by the sleeve down to the chair so that he would not get up. “This unfortunate holiday at the messenger’s place deprives me of pleasure and interrupts you. I am very sad to leave your delightful evening, ”he said to Anna Pavlovna.
His daughter, Princess Helene, slightly holding the folds of her dress, walked between the chairs, and her smile shone even brighter on her beautiful face. Pierre looked with almost frightened, enthusiastic eyes at this beauty when she passed him.
“Very good,” said Prince Andrew.
“Very much,” said Pierre.
Passing by, Prince Vasily grabbed Pierre by the hand and turned to Anna Pavlovna.
“Form this bear for me,” he said. - Here he has been living with me for a month, and for the first time I see him in the light. Nothing is so necessary young man as a society of smart women.

Anna Pavlovna smiled and promised to take care of Pierre, who, she knew, was a relative of Prince Vasily's father. An elderly lady, who had previously sat with ma tante, hastily got up and overtook Prince Vasily in the hall. All the pretense of interest had disappeared from her face. Her kind, tearful face expressed only concern and fear.
- What do you tell me, prince, about my Boris? She said, catching up with him in the hall. (She pronounced the name Boris with a special emphasis on o). - I cannot stay longer in Petersburg. Tell me, what news can I bring my poor boy?
Despite the fact that Prince Vasily listened reluctantly and almost impolitely to the elderly lady and even showed impatience, she smiled affectionately and touchingly at him and, so that he would not leave, took his hand.
“That you should say a word to the sovereign, and he will be directly transferred to the guard,” she asked.
- Believe me, I will do everything that I can, princess, - answered Prince Vasily, - but it is difficult for me to ask the sovereign; I would advise you to turn to Rumyantsev, through Prince Golitsyn: that would be smarter.
The elderly lady bore the name of Princess Drubetskaya, one of the best surnames in Russia, but she was poor, long gone out of the world and lost her former connections. She has come now to procure a determination in her guard. only son... Only then, in order to see Prince Vasily, she introduced herself and came to Anna Pavlovna's for the evening, only then she listened to the history of the viscount. She was frightened by the words of Prince Vasily; once that beautiful face expressed bitterness, but this lasted only a minute. She smiled again and grabbed the arm of Prince Vasily more tightly.
“Listen, prince,” she said, “I never asked you, I never will, I never reminded you of my father’s friendship with you. But now, I conjure you by God, do it for my son, and I will consider you a benefactor, ”she added hastily. - No, you are not angry, but you promise me. I asked Golitsyn, he refused. Soyez le bon enfant que vous avez ete, [Be the kind guy you were,] she said, trying to smile, while there were tears in her eyes.
“Dad, we'll be late,” said Princess Helene, who was waiting at the door, turning her beautiful head on antique shoulders.
But influence in the world is capital that must be protected so that it does not disappear. Prince Vasily knew this, and, once realizing that if he began to ask for everyone who asked him, then soon he would not be able to ask for himself, he rarely used his influence. In the affair of Princess Drubetskoy, he felt, however, after her new call, something like a reproach of conscience. She reminded him of the truth: he owed his first steps in the service to her father. In addition, he saw from her receptions that she was one of those women, especially mothers, who, once having taken something in their heads, would not lag behind until their desires were fulfilled, and otherwise they were ready for the daily, every minute harassment and even on the stage. This last consideration shook him.
“Chere Anna Mikhailovna,” he said with his usual familiarity and boredom in his voice, “it's almost impossible for me to do what you want; but in order to prove to you how I love you and honor the memory of your late father, I will do the impossible: your son will be transferred to the guard, here is my hand for you. Are you satisfied?
- My dear, you are a benefactor! I didn’t expect anything else from you; I knew how kind you are.
He wanted to leave.
- Wait, two words. Une fois passe aux gardes ... [Since he will go to the guard ...] - She hesitated: - You are good with Mikhail Ilarionovich Kutuzov, recommend Boris to him as an adjutant. Then I would be at peace, and then ...
Prince Vasily smiled.
“I don’t promise that.” You do not know how Kutuzov has been besieged since he was appointed commander-in-chief. He told me himself that all the Moscow ladies had conspired to give him all their children as adjutants.
- No, promise, I will not let you in, dear, my benefactor ...
- Dad! - Again the beauty repeated in the same tone, - we will be late.
- Well, au revoir, [goodbye] goodbye. See?
- So tomorrow you will report to the sovereign?
- Certainly, but I do not promise Kutuzov.
“No, promise, promise, Basile, [Vasily],” Anna Mikhailovna said after him, with the smile of a young coquette, which once must have been peculiar to her, but now did not go like that to her emaciated face.
She, apparently, forgot her years and used, out of habit, all the old women's remedies. But as soon as he left, her face again assumed the same cold, feigned expression that had been on him before. She returned to the circle in which the viscount continued to tell, and again pretended to listen, waiting for the time to leave, since her work was done.
- But how do you find all this last comedy du sacre de Milan? [the Milanese anointing?] - said Anna Pavlovna. Et la nouvelle comedie des peuples de Genes et de Lucques, qui viennent presenter leurs voeux a M. Buonaparte assis sur un trone, et exaucant les voeux des nations! Adorable! Non, mais c "est a en devenir folle! On dirait, que le monde entier a perdu la tete. [And here is a new comedy: the peoples of Genoa and Lucca express their wishes to Monsieur Bonaparte. And Monsieur Bonaparte sits on the throne and fulfills the wishes of the peoples. 0! It's amazing! No, it can go crazy. You'd think the whole world has lost its head.]
Prince Andrey grinned, looking straight into Anna Pavlovna's face.
“Dieu me la donne, gare a qui la touche,” he said (the words of Bonaparte, spoken at the laying on of the crown). - On dit qu "il a ete tres beau en prononcant ces paroles, [God gave me a crown. Trouble is to the one who touches it. - They say he was very good, pronouncing these words,] - he added and repeated these words again in Italian: "Dio mi la dona, guai a chi la tocca".
- J "espere enfin," Anna Pavlovna continued, "que ca a ete la goutte d" eau qui fera deborder le verre. Les souverains ne peuvent plus supporter cet homme, qui menace tout. [Hope it was finally the drop that will overflow the glass. Sovereigns can no longer tolerate this man who threatens everything.]
- Les souverains? Je ne parle pas de la Russie, said the Viscount, courteously and hopelessly: Les souverains, madame! Qu "ont ils fait pour Louis XVII, pour la reine, pour madame Elisabeth? Rien," he continued, animating. "Et croyez moi, ils subissent la punition pour leur trahison de la cause des Bourbons. Les souverains? Ils envoient des ambassadeurs complimenter l "usurpateur. [Sovereigns! I'm not talking about Russia. Sovereigns! But what did they do for Louis XVII, for the queen, for Elizabeth? Nothing. And believe me, they are being punished for their betrayal of the Bourbon cause. Sovereigns! They send ambassadors to greet the thief of the throne.]
And with a contemptuous sigh, he changed his position again. Prince Hippolyte, who had been looking at the viscount in his lorgnette for a long time, suddenly at these words turned his whole body to the little princess and, asking her for a needle, began to show her, drawing with a needle on the table, the coat of arms of Condé. He interpreted this coat of arms to her with such a significant air, as if the princess had asked him about it.
- Baton de gueules, engrele de gueules d "azur - maison Conde, [A phrase that cannot be translated literally, since it consists of conventional heraldic terms that are not quite accurately used. The general meaning is this: The coat of arms of Condé represents a shield with red and blue narrow jagged stripes ,] - he said.

Carboniferous period

Seymuria

Anapsid group

Synapsid group.

Diapsid group

• Scaly;
• Turtles;
• Crocodiles;
• Beakheads.

tuberculosis,

The answer left the guest

The body is subdivided into the head, neck, torso, tail, and five-fingered limbs.
The skin is dry, devoid of glands and covered with a horny covering that protects the body from drying out. The growth of the animal is accompanied by periodic molt.
The skeleton is strong, ossified. The spine consists of five sections: cervical, thoracic, lumbar, sacral and caudal. The shoulder and pelvic girdles of the limbs are strengthened and connected to the axial skeleton. The ribs and chest are developed.
The musculature is more differentiated than that of amphibians. Cervical and intercostal muscles, subcutaneous muscles are developed. The movements of the parts of the body are more varied and faster.
The digestive tract is longer than that of amphibians, and is more clearly differentiated into sections. Food is captured by jaws with numerous sharp teeth. Walls oral cavity and the esophagus are equipped with powerful muscles that push large portions of food into the stomach. At the border of the small and large intestines, there is a cecum, which is especially well developed in herbivorous land turtles.
Respiratory organs - lungs - have a large respiratory surface due to the cellular structure. Developed airways - the trachea, bronchi, in which the air is moistened and does not dry out the lungs. Ventilation of the lungs occurs by changing the volume chest.
The heart is three-chambered, but there is an incomplete longitudinal septum in the ventricle, which prevents complete mixing of arterial and venous blood. Most of the body of reptiles is supplied with mixed blood with a predominance of arterial, therefore, the metabolic rate is higher than that of amphibians.

What animals did the reptiles come from? When did the ancestors of reptiles live?

However, reptiles, like fish and amphibians, are poikilothermic (cold-blooded) animals, the body temperature of which depends on the temperature of the environment.
The excretory organs are the pelvic kidneys. Through the ureters, urine flows into the cloaca, and from it into the bladder. In it, water is additionally sucked into the blood capillaries and returned to the body, after which the urine is excreted. The end product of nitrogen metabolism excreted in the urine is uric acid.
The brain has a larger relative size than that of amphibians. Better developed large hemispheres forebrain with rudiments of the cortex and cerebellum. The forms of behavior of reptiles are more complex. The senses are better adapted to the terrestrial lifestyle.
Fertilization is only internal. The eggs, protected from drying out by a leathery or shell shell, are laid by reptiles on land. The embryo in the egg develops into aquatic shell... Direct development.

The origin of reptiles

Reptile pedigree

About 300 million

years ago, the first amphibians appeared on Earth. However, already at the end of this period and further, the climate became dry again, and the descendants of the first amphibians began to develop in two directions. Some remained near the water and turned into modern amphibians. Others, on the contrary, began to adapt to the dry climate and turned into reptiles.

What changes did they have? First of all, a dense shell appeared on the eggs, so that they could be laid on land. In addition, reptiles began to lay large eggs, with big amount yolk. The development of the embryo lengthened, but it was not a helpless larva that began to hatch, but a fully formed animal, differing from the adult only in smaller size, already fully adapted to the conditions of life on land.

Adult reptiles have also acquired the changes necessary for life on land. They have dense keratinized skin that prevents evaporation. Oxygen does not pass through such skin. Therefore, the lungs have changed: they have acquired a cellular structure, that is, their working surface has greatly increased. In addition, ribs appeared, a chest was formed, and the breathing process became an active way of expanding and contracting the chest. A septum has appeared in the ventricle of the heart, although it is not completely complete, so that partially the blood in it is mixed. The division of venous and arterial blood in reptiles is much more perfect than in amphibians. However, they remain cold-blooded animals, their body temperature depends on the ambient temperature.

In the skeleton, along with the appearance of ribs, the cervical region was greatly lengthened and the head became more mobile. When seizing prey, reptiles do not turn with their whole body, as fish and amphibians do, but only turn their head. The senses have also improved. The improvement of the brain should be especially noted. Due to the more varied movements, the cerebellum, which is responsible for the coordination of movements, increased. The brain and sensory organs have a more complex structure, as well as the behavior of reptiles in comparison with amphibians.

Ancient extinct reptiles - tyrannosaurus, tailed flying lizard, brontosaurus, ichthyosaurus

The heyday and extinction of ancient reptiles

So, the reptiles became much more active and, not afraid to move away from the water, spread widely across the Earth. Gradually, many species were formed among them. The appearance of giant reptiles is especially characteristic of this time. So, some dinosaurs ("terrible lizards") were up to 30 meters long and weighing up to 50 tons - the largest terrestrial vertebrates that have ever existed on Earth. Such giants were even forced to return to a semi-aquatic lifestyle again - their mass decreases in water. They roamed the shallow waters and fed on coastal and aquatic plants, reaching them with the help of their long necks. Then there were predators, also very large, up to 10 meters long. Some reptiles that lived then even completely returned to the aquatic lifestyle, although they did not lose pulmonary respiration. Such, for example, was the ichthyosaurus, or fish-lizard, in shape very similar to the modern dolphin. Finally, there were also flying lizards - pterodactyls.

Thus, reptiles have mastered all habitats - terrestrial, water and air. They formed many species and became the dominant animals on Earth.

But 70-90 million years ago, the climate on most of the Earth changed dramatically, became cold. At the same time, there are more diverse species of warm-blooded mammals competing with reptiles. This led to the fact that most of the reptiles, primarily all giant forms, became extinct, since the giants cannot hide in shelters for wintering. Few reptiles have survived to this day - turtles, crocodiles, lizards and snakes. By the way, among them, the largest are found only in warm countries and are aquatic or semi-aquatic.

The origin and evolution of reptiles. Brief description of the main groups of fossil reptiles.

The appearance of reptiles on Earth is the greatest event in evolution.

It had tremendous consequences for the whole of nature. The origin of reptiles is one of the important questions in the theory of evolution, the process that resulted in the appearance of the first animals belonging to the Reptilia class. The first terrestrial vertebrates appeared in the Devonian (more than 300 million years ago). These were shell-headed amphibians - stegocephals. They were closely related to water bodies, since they multiplied only in water, lived near water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

Carboniferous period

Seymuria

All reptiles can be divided into three groups:

1) anapsids - with a solid cranial shell (cotilosaurs and turtles);

2) synapsids - with one zygomatic arch (bestial, plesiosaurs and possibly ichthyosaurs) and

3) diapsids - with two arches (all other reptiles).

Anapsid group is the oldest branch of reptiles, which have many common features in the structure of the skull with the fossil stegocephals, since not only many of their early forms (cotylosaurs), but even some modern ones (some turtles) have a continuous cranial shell. Turtles are the only living representatives of this ancient group of reptiles. They separated, apparently, directly from the cotylosaurs. Already in the Triassic, this ancient group was fully formed and, thanks to its extreme specialization, has survived to the present time, almost unchanged, although in the process of evolution some groups of turtles several times passed from a terrestrial lifestyle to an aquatic one, in connection with which they almost lost their bony shields then acquired them again.

Synapsid group. Marine fossils of reptiles - ichthyosaurs and plesiosaurs - separated from the group of cotylosaurs. Plesiosauria, which are synaptosaurs, were marine reptiles. They had a wide, barrel-shaped, flattened body, two pairs of powerful limbs modified into swimming fins, a very long neck ending in a small head, and a short tail. The skin was bare. Numerous sharp teeth sat in separate cells. The sizes of these animals varied over a very wide range: some species were only half a meter in length, but there were also giants, reaching 15 m. While the plesiosaurs, having adapted to aquatic life, still retained the appearance of terrestrial animals, the ichthyosauria (Ichthyosauria), belonging to the ichthyoptergia, acquired similarities with fish and dolphins. The body of the ichthyosaurs was fusiform, the neck was not pronounced, the head was elongated, the tail had a large fin, the limbs were in the form of short flippers, and the hind ones were much smaller than the front ones. The skin was bare, numerous sharp teeth (adapted to feeding on fish) sat in a common furrow, there was only one zygomatic arch, but of an extremely peculiar structure. The sizes varied from 1 to 13 m.

Diapsid group includes two subclasses: lepidosaurs and archosaurs. The earliest (Upper Permian) and most primitive group of lepidosaurs is the order of eosuchia (Eosuchia). They are still very poorly studied, lounginia is better known than others - a small reptile resembling a lizard in physique, with relatively weak limbs that had the usual reptilian structure. Its primitive features are expressed mainly in the structure of the skull, the teeth are located both on the jaws and on the palate.

Now there are about 7000 species of reptiles, i.e.

Reptiles are ... Reptiles: photos

That is, almost three times more than modern amphibians. The living reptiles are divided into 4 groups:

• Scaly;
• Turtles;
• Crocodiles;
• Beakheads.

The most numerous order of scaly (Squamata), including about 6500 species, is the only currently thriving group of reptiles, widespread across the globe and making up the bulk of the reptiles of our fauna. This order includes lizards, chameleons, amphisbens and snakes.

Much less turtles (Chelonia) - about 230 species, represented in the animal kingdom of our country by several species. This is a very ancient group of reptiles that have survived to this day thanks to a kind of protective device - the shell in which their body is chained.

Crocodiles (Crocodylia), of which there are about 20 known species, inhabit the continental and coastal water bodies of the tropics. They are direct descendants of the ancient highly organized reptiles of the Mesozoic.

The only species of modern beak-headed (Rhynchocephalia) - the tuatara has many extremely primitive features and has survived only in New Zealand and the adjacent small islands.

Reptiles lost their dominant position on the planet mainly due to competition with birds and mammals against the background of a general cooling, which is confirmed by the current ratio of the number of species of different classes of terrestrial vertebrates. If the share of amphibians and reptiles, most dependent on the temperature of the environment, on a global scale is quite high (10.5 and 29.7%), then in the CIS, where the area of ​​warm regions is relatively small, they amount to only 2.6 and 11.0% ...

Reptiles, or reptiles, of Belarus are the northern "outpost" of this diverse class of vertebrates. Of the more than 6500 species of reptiles that now live on our planet, only 7 are represented in the republic.

In Belarus, which does not differ in the warmth of the climate, there are only 1.8% of reptiles and 3.2% of amphibians. It is important to note that the decrease in the proportion of amphibians and reptiles in the fauna of northern latitudes occurs against the background of a decrease in the total number of species of terrestrial vertebrates. Moreover, out of four orders of modern reptiles, only two live in the CIS and Belarus (turtles and scaly ones).

The Cretaceous period was marked by the collapse of the reptiles, the almost complete extinction of the dinosaurs. This phenomenon is a mystery to science: how did a huge, prosperous, ecological reptile army, which had representatives from the smallest creatures to unimaginable giants, so suddenly died out, leaving only relatively small animals?

It was these groups that at the beginning of the modern Cenozoic era occupied a dominant position in the animal kingdom. And among the reptiles of 16-17 orders that existed in the heyday, only 4 survived. Of these, one is represented by the only primitive species - tuberculosis, preserved only on two dozen islands near New Zealand.

Two other orders - turtles and crocodiles - unite a relatively small number of species - about 200 and 23, respectively. And only one order - scaly ones, which includes lizards and snakes, can be assessed as thriving in the current evolutionary era. It is a large and varied group of over 6,000 species.

Reptiles are distributed throughout the globe, except for Antarctica, but extremely unevenly. If in the tropics their fauna is the most diverse (in some regions, 150-200 species live), then only a few species penetrate into high latitudes (in Western Europe, only 12).

The origin and evolution of reptiles. Brief description of the main groups of fossil reptiles.

The appearance of reptiles on Earth is the greatest event in evolution.

It had tremendous consequences for the whole of nature. The origin of reptiles is one of the important questions in the theory of evolution, the process that resulted in the appearance of the first animals belonging to the Reptilia class. The first terrestrial vertebrates appeared in the Devonian (more than 300 million years ago). These were shell-headed amphibians - stegocephals. They were closely related to water bodies, since they multiplied only in water, lived near water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

Carboniferous period

Seymuria

All reptiles can be divided into three groups:

1) anapsids - with a solid cranial shell (cotilosaurs and turtles);

2) synapsids - with one zygomatic arch (bestial, plesiosaurs and possibly ichthyosaurs) and

3) diapsids - with two arches (all other reptiles).

Anapsid group is the oldest branch of reptiles, which have many common features in the structure of the skull with the fossil stegocephals, since not only many of their early forms (cotylosaurs), but even some modern ones (some turtles) have a continuous cranial shell. Turtles are the only living representatives of this ancient group of reptiles. They separated, apparently, directly from the cotylosaurs. Already in the Triassic, this ancient group was fully formed and, thanks to its extreme specialization, has survived to the present time, almost unchanged, although in the process of evolution some groups of turtles several times passed from a terrestrial lifestyle to an aquatic one, in connection with which they almost lost their bony shields then acquired them again.

Synapsid group. Marine fossils of reptiles - ichthyosaurs and plesiosaurs - separated from the group of cotylosaurs. Plesiosauria, which are synaptosaurs, were marine reptiles. They had a wide, barrel-shaped, flattened body, two pairs of powerful limbs modified into swimming fins, a very long neck ending in a small head, and a short tail. The skin was bare. Numerous sharp teeth sat in separate cells. The sizes of these animals varied over a very wide range: some species were only half a meter in length, but there were also giants, reaching 15 m.

The origin of reptiles

V While the plesiosaurs, having adapted to aquatic life, still retained the appearance of terrestrial animals, the ichthyosauria (Ichthyosauria), belonging to the ichthyoptergia, acquired similarities with fish and dolphins. The body of the ichthyosaurs was fusiform, the neck was not pronounced, the head was elongated, the tail had a large fin, the limbs were in the form of short flippers, and the hind ones were much smaller than the front ones. The skin was bare, numerous sharp teeth (adapted to feeding on fish) sat in a common furrow, there was only one zygomatic arch, but of an extremely peculiar structure. The sizes varied from 1 to 13 m.

Diapsid group includes two subclasses: lepidosaurs and archosaurs. The earliest (Upper Permian) and most primitive group of lepidosaurs is the order of eosuchia (Eosuchia). They are still very poorly studied, lounginia is better known than others - a small reptile resembling a lizard in physique, with relatively weak limbs that had the usual reptilian structure. Its primitive features are expressed mainly in the structure of the skull, the teeth are located both on the jaws and on the palate.

Now there are about 7000 species of reptiles, that is, almost three times more than modern amphibians. The living reptiles are divided into 4 groups:

• Scaly;
• Turtles;
• Crocodiles;
• Beakheads.

The most numerous order of scaly (Squamata), including about 6500 species, is the only currently thriving group of reptiles, widespread across the globe and making up the bulk of the reptiles of our fauna. This order includes lizards, chameleons, amphisbens and snakes.

Much less turtles (Chelonia) - about 230 species, represented in the animal kingdom of our country by several species. This is a very ancient group of reptiles that have survived to this day thanks to a kind of protective device - the shell in which their body is chained.

Crocodiles (Crocodylia), of which there are about 20 known species, inhabit the continental and coastal water bodies of the tropics. They are direct descendants of the ancient highly organized reptiles of the Mesozoic.

The only species of modern beak-headed (Rhynchocephalia) - the tuatara has many extremely primitive features and has survived only in New Zealand and the adjacent small islands.

Reptiles lost their dominant position on the planet mainly due to competition with birds and mammals against the background of a general cooling, which is confirmed by the current ratio of the number of species of different classes of terrestrial vertebrates. If the share of amphibians and reptiles, most dependent on the temperature of the environment, on a global scale is quite high (10.5 and 29.7%), then in the CIS, where the area of ​​warm regions is relatively small, they amount to only 2.6 and 11.0% ...

Reptiles, or reptiles, of Belarus are the northern "outpost" of this diverse class of vertebrates. Of the more than 6500 species of reptiles that now live on our planet, only 7 are represented in the republic.

In Belarus, which does not differ in the warmth of the climate, there are only 1.8% of reptiles and 3.2% of amphibians. It is important to note that the decrease in the proportion of amphibians and reptiles in the fauna of northern latitudes occurs against the background of a decrease in the total number of species of terrestrial vertebrates. Moreover, out of four orders of modern reptiles, only two live in the CIS and Belarus (turtles and scaly ones).

The Cretaceous period was marked by the collapse of the reptiles, the almost complete extinction of the dinosaurs. This phenomenon is a mystery to science: how did a huge, prosperous, ecological reptile army, which had representatives from the smallest creatures to unimaginable giants, so suddenly died out, leaving only relatively small animals?

It was these groups that at the beginning of the modern Cenozoic era occupied a dominant position in the animal kingdom. And among the reptiles of 16-17 orders that existed in the heyday, only 4 survived. Of these, one is represented by the only primitive species - tuberculosis, preserved only on two dozen islands near New Zealand.

Two other orders - turtles and crocodiles - unite a relatively small number of species - about 200 and 23, respectively. And only one order - scaly ones, which includes lizards and snakes, can be assessed as thriving in the current evolutionary era. It is a large and varied group of over 6,000 species.

Reptiles are distributed throughout the globe, except for Antarctica, but extremely unevenly. If in the tropics their fauna is the most diverse (in some regions, 150-200 species live), then only a few species penetrate into high latitudes (in Western Europe, only 12).

Late Devonian. These were shell-headed amphibians (the outdated name is stegocephalus; now most of these animals are included in the labyrinthodonts). They lived near water bodies and were closely related to them, since they multiplied only in water. The development of areas remote from water bodies required a significant restructuring of the organization: adaptation to protecting the body from drying out, breathing oxygen from the atmosphere, efficient movement on a solid substrate, and the ability to reproduce outside the water. These are the basic prerequisites for the emergence of a qualitatively different new group of animals - reptiles. These rearrangements were quite complex, for example, it required the design of powerful lungs, a change in the nature of the skin.

From the point of view of the progressive method of classification - cladistics, which considers the position of organisms in terms of their origin, and not the features of organization (in particular, the classic "reptilian" signs of crocodiles, such as cold-bloodedness and limbs located on the sides of the torso, are secondary), reptiles are all developed amniotes, with the exception of taxa included in the clade of synapsids and, possibly, anapsids.

Carboniferous period

The remains of the most ancient reptiles are known from the Upper Carboniferous (about 300 million years ago). It is believed that isolation from amphibian ancestors should have begun, apparently, in the Middle Carboniferous (320 Ma), when from anthracosaurs like Diplovertebron, the forms were isolated, apparently better adapted to the terrestrial way of life. From such forms, a new branch appears - Seymouriomorpha, the remains of which were found in the Upper Carboniferous - Middle Permian. Some paleontologists classify these animals as amphibians.

Permian period

Remains of Cotylosauria are known from the Upper Permian deposits of North America, Western Europe, Russia and China. According to a number of signs, they are still very close to stegocephals. Their skull was in the form of a solid bone box with holes only for the eyes, nostrils and the parietal organ, the cervical spine was poorly shaped (although there is a structure characteristic of modern reptiles of the first two vertebrae - atlanta and epistrophy), the sacrum had from 2 to 5 vertebrae; in the shoulder girdle, kleitrum, a skin bone characteristic of fish, was preserved; the limbs were short and widely spaced.

Further evolution of reptiles was conditioned by their variability due to the influence of various living conditions that they encountered during reproduction and dispersal. Most of the groups have become more mobile; their skeleton has become lighter, but at the same time and stronger. Reptiles used a more varied diet than amphibians. The technique of obtaining it changed. In this regard, the structure of the limbs, axial skeleton and skull underwent significant changes. The majority of the limbs became longer, the pelvis, gaining stability, was attached to two or more sacral vertebrae. In the shoulder girdle disappeared "fish" bone cleithrum. The solid carapace of the skull underwent partial reduction. In connection with the more differentiated muscles of the jaw apparatus, pits and bony bridges dividing them - arcs, which served to attach a complex system of muscles, appeared in the temporal region of the skull.

Synapsids

The main ancestral group, which gave all the variety of modern and fossil reptiles, was probably cotylosaurs, but the further development of reptiles went in different ways.

Diapsids

The next group to separate from the cotylosaurs was the Diapsida. Their skull has two temporal cavities, located above and below the postorbital bone. Diapsids at the end of the Paleozoic (Permian) gave extremely wide adaptive radiation to systematic groups and species, which are found both among extinct forms and among today's reptiles. Among the diapsids, there are two main groups: Lepidosauromorpha and Archosauromorpha. The most primitive diapsids from the group of lepidosaurs - the order eosuchia (Eosuchia) - were the ancestors of the order Beakheads, of which only one genus has survived, the tuatara.

At the end of the Permian, scaly diapsids (Squamata) separated from primitive diapsids, which became numerous in the Cretaceous. Towards the end of the Cretaceous period, snakes evolved from lizards.

Origin of archosaurs

see also

• Temporal arches

Notes (edit)

Literature

• N.P. Naumov, N.N. Kartashev Part 2. Reptiles, birds, mammals// Zoology of vertebrates. - M.: Higher school, 1979 .-- S. 272.

Transitional form

A transitional form is an organism with an intermediate state, which necessarily exists with a gradual transition from one biological type of structure to another. Transitional forms are characterized by the presence of more ancient and primitive (in the sense of primary) traits than their later relatives, but, at the same time, the presence of more progressive (in the sense of later) traits than their ancestors. As a rule, when speaking of intermediate forms, they mean fossil species, although intermediate species should not necessarily die out. Many transitional forms are known, illustrating the origin of tetrapods from fish, reptiles from amphibians, birds from dinosaurs, mammals from theriodonts, cetaceans from land mammals, horses from a five-toed ancestor, and humans from ancient hominids.

Reptiles

Reptiles, or reptiles (Latin Reptilia), are a class of predominantly terrestrial vertebrates, including modern turtles, crocodiles, beak-headed and scaly ones. Cladists are classified as reptiles and birds, since otherwise the former are obtained by the paraphyletic group.

V XVIII-XIX centuries together with amphibians they united in a group of reptiles - cold-blooded terrestrial vertebrates. Traditionally, this group included various vertebrates that, according to their initial ideas, were similar in their organization to modern reptiles (for example, some synapsids - the ancestors of modern mammals). However, at present, questions about the physiology of many extinct groups of organisms remain open, and data on their genetic and evolutionary relationships do not support this kind of classification.

Many authors adhering to traditional taxonomy believe that archosaurs (crocodiles, pterosaurs, dinosaurs, etc.) should be removed from the class of reptiles and combined into one class with birds, since birds are actually a specialized group of dinosaurs. About 10,885 species of non-avian reptiles are known in the world; 77 species live on the territory of Russia.

The largest land animals belonged to dinosaurs - representatives of ancient reptiles, currently represented only by birds. Reptiles flourished during the Mesozoic era, when they dominated land, sea and air. Late Cretaceous most of reptiles became extinct. Modern non-avian reptiles are only scattered remnants of that world. However, the ancient reptiles gave rise to the currently thriving group of animals - birds, and many adaptations that determined the evolutionary success of this group appeared even in its archosaurian ancestors, which were a specialized group of diapsids (warm-bloodedness, heat-insulating body cover - feathers, developed brain, and etc).