Carboniferous, Carboniferous period. Forests and plants of the Carboniferous period When was the Carboniferous period

The Carboniferous period began 360 million years ago and ended 300 million years ago. The Carboniferous lasted about 60 million years. It was at this time that limestone deposits near Moscow were formed, so that almost the entire Paleozoic fauna of the Moscow region dates back to the Carboniferous period.

The period owes its name to the huge deposits of coal. Coal arose from a huge amount of dead plants, which accumulated and were gradually buried without having time to decompose. These plants, primarily lycophytes and horsetails, sometimes reached 30 meters in height. The first differentiation of vegetation into 4 phytogeographic regions occurred.

Terrestrial vertebrates have become noticeably more diverse. In addition to amphibians, the land was inhabited by parareptiles and true reptiles - lepidosaurs and lizards. Unlike amphibians, which are forced to stay near water, reptiles had skin that could hold water, and their eggs were enclosed in a shell that prevented them from drying out. The land was mastered by gastropods - snails with a pulmonary type of breathing.

Terrestrial arthropods, and primarily insects, experienced a particular flourishing - some dragonflies had a wingspan of up to 1 meter. In the forests there were giant meter-long centipedes, which could be formidable predators. It was warm on Earth, there was a lot of carbon dioxide in the atmosphere, which increased the greenhouse effect. Apparently, there was also more oxygen than now, since the size of insects is limited by the oxygen concentration in the atmosphere.

However, apparently, it was not always warm and not everywhere. There is evidence that during the Carboniferous period there were several eras of glaciation. Sea level changed frequently. Thus, among the deposits of the Carboniferous period in the Moscow region there are land deposits with coal deposits, and deposits of the river mouth, and typically marine deposits.

In the seas, brachiopods, bryozoans, echinoderms - crinoids and sea urchins, mollusks - gastropods and cephalopods - nautiloids, flourish. Corals build reefs, and fusulinid foraminifera in some places multiply so much that fusulinid limestones are formed from their shells.

Aquatic vertebrates are represented mainly by sharks and ray-finned fish. Trilobites and straight-shelled cephalopods, which were numerous in previous periods, become rare, and it is felt that these groups are gradually dying out.

A couple of weeks ago, returning to Moscow, near the Freser railway station, a small pile of motley clays and limestones was noticed. The fact that these are precisely limestones and clays (and, for example, not a pile of broken bricks and concrete) is clearly visible from the train, since the dump is located near the tracks, on the left (if you go towards Moscow) almost immediately as the platform ends, near the garages. Today we were able to take a closer look at the dump itself. Unfortunately, no significant finds... >>>

Paleoclub The purpose of creating the club is the desire to unite children and their parents who are interested not only in the nature around us, but also in what life looked like many millions of years ago before humans appeared on the planet, how it changed and what it looked like in different geological periods. Get to know more closely the fossil remains of animals and plants that inhabited our planet many millions of years ago, not only through the glass of a museum showcase, but also by holding in your hands an antiquity you found with your own hands! ... >>>

I present to your attention the continuation of a series of publications on the fauna of the Carboniferous forest accompanying plants. It must be said that a paradoxical situation has arisen with the study of insects from the Carboniferous period of Donbass; with more than three centuries of history of the study and development of coal deposits and other minerals in Donbass, they have practically not been studied. Single finds of insects in deposits of the upper Carboniferous in the 20s of the last century and in the early 2000s the finds of insects made by me were described... >>>

Carboniferous period (Carboniferous)

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According to geochronological scale Carboniferous period, or, as it is more often called - carbon, is the penultimate period of the Paleozoic era, occurring after the Devonian and before the Permian. It began 358 million years ago, lasted about 60 million years and ended 298 million years ago. Carboniferous was notable for the fact that it was during this period that huge accumulations of coal deposits were deposited in the earth's crust, and the outlines of the ancient supergiant continent of Pangea first appeared on the globe.

Main subsections of the Carboniferous period, its geography and climatic features

The Carboniferous period is usually divided into two superdivisions: Pennsylvanian and Mississippian. The Pennsylvanian is in turn divided into the Upper and Middle Carboniferous, the Mississippian equally corresponds to the Lower. The Upper Carboniferous includes the Gzhel and Kasimov stages, the Middle is subdivided into the Moscow and Bashkir, and the Lower Carboniferous consists of three stages - Serpukhovian, Visean and ends it, like the entire Carboniferous as a whole - Tournaisian.

Throughout the Carboniferous, the southern continent of Gondwana moved closer and closer to the more northern Laurasia, which ended with their partial reunification by the end of the Carboniferous period. Before the collision, under the influence of tidal forces, Gondwana turned clockwise so that its eastern part, which later provided the basis for the creation of India, Australia and Antarctica, moved south, and its western part, from which present-day Africa and South America later emerged, ended up on north. The result of this turn was the formation of the Tethys Ocean in the eastern hemisphere, and the disappearance of the old Rhea Ocean. Simultaneously with these processes, the smaller continental elements of the Baltic and Siberia converged, until, finally, the ocean between them completely ceased to exist, and these continents collided. All this continental restructuring was accompanied by the emergence of new mountain ranges and violent volcanic activity.

By the beginning of the Carboniferous period, the coastal mountain landscape, which did not allow moist air masses to pass to the territory of the continents, and which caused heat and drought in large parts of the land in the Devonian, due to the advance of the seas, was washed away and collapsed into the abyss of water. As a result, a warm and humid climate, akin to the current tropical one, was established throughout the continents, which contributed to the further development and prosperity of organic life on the planet.

Sedimentation in the Carboniferous period

Sedimentary deposits of the seas in the Carboniferous period were formed from clay, sandstone, limestone, shale and rocks of volcanic activity. Clay, sandstone and small amounts of other rocks accumulated on land. In some areas of land, namely in places where carbon forests grew, the main sedimentary rocks at this stage were coal, after which this period was named.

Intense mountain-building processes, accompanied by active volcanic activity, caused the release of huge masses of volcanic ash into the atmosphere of the planet, which, distributed over land, served as an excellent fertilizer for Carboniferous soils. This created the preconditions for primeval forests, finally breaking away from wet swamps, lagoons and other coastal areas, to move deeper into the continents. Carbon dioxide, actively released from the bowels of the earth during volcanic processes, also contributed to the increasing growth of greenery. And along with the forests, land and living creatures moved deeper into the continents.

Rice. 1 - Animals of the Carboniferous Period

But it’s still worth starting with the ancestors of all living things - the oceanic, sea depths and other bodies of water.

Underwater animals of the Carboniferous period were even more diverse than in the Devonian. Foraminifera of various species became widely developed, and later, by the middle of the period, Schwagerina spread. Basically, they were the main source of limestone accumulation. Among the corals, there was a displacement of the tabulaids by chaetetids, of which almost none remained by the end of the Carboniferous period. Brachiopods have also developed unusually. Among them, the most noticeable are productides and spirepherides. In some places, the seabed was completely covered with sea urchins. Also, large areas of the bottom plains are overgrown with thickets of crinoids. Conodonts are also especially numerous at this time. Cephalopods in the Carboniferous were mainly represented by a group of ammonoids with a simple structure of partitions, which included, for example, goniatites and agoniatites, whose lobed lines and shell sculpture underwent a number of evolutionary improvements, becoming much more complex. But nautiloids did not take root in the Carboniferous. By the end of the period, almost all of them disappeared, only some varieties of nautiluses remained, which have safely survived to this day. All kinds of gastropods and bivalves also received an impetus in their development, and the latter populated not only the depths of the sea, but also moved to freshwater inland rivers and lakes.

During the Carboniferous period, almost all trilobites died out; just a few periods ago, they reigned supreme over the entire territory of the aquatic world and witnessed the emergence of terrestrial life. This happened for two main reasons. The body structure of trilobites was flawed and retarded in development compared to other inhabitants of the depths. The shells could not protect their soft bellies, and over time they never grew organs of attack and defense, which is why they often became prey for sharks and other underwater predators. The second reason was the unusually expanded and multiplied mollusks, which ate the same food as they did. Often, the passing army of mollusks destroyed everything edible in its path, thereby dooming the hapless and helpless trilobites to starvation. Some species of trilobites held on to existence until the last, having learned, like today's armadillos, to curl up into a hard chitinous ball. But by that time, many predatory fish of the Carboniferous period had developed their jaws to such an extent that it was not difficult for them to bite through some chitinous ball.

And on land at that time there was a paradise for insects. And despite the fact that many of their ancient species, which descended from branching varieties of Ordovician trilobites, became extinct in the Upper Carboniferous, this served as a surge in the emergence of an even greater variety of insects. While various scorpions and crustaceans were breeding in the puddles and swamp slush, their renewed relatives were intensively exploring the airspace. The smallest flying insects were 3 centimeters long, while the wingspan of some Stenodicty and Meganeuron dragonflies reached 1 meter (Fig. 2). It is noteworthy that the body of the ancient meganeura dragonfly consisted of 21 segments, 6 of which were on the head, 3 on the chest, 11 on the abdomen, and the terminal segment was very similar to the awl-shaped tail of distant relatives - trilobites. The insect had many pairs of segmented legs, with the help of which it both walked and swam beautifully. Meganeuras were born in water and for some time led the life of trilobites, until the molting process began, after which the insect was reborn in its new dragonfly-like appearance.

Rice. 2 - Meganeura (insect of the Carboniferous period)

Not only dragonflies, but also the first termites, and Eurypterus gave rise to ants, evolved from extinct ancient Orthoptera. But be that as it may, almost everything insects of the Carboniferous period could reproduce only in water, and therefore were tied to sea coasts, inland rivers, seas, lakes and swampy areas. For insects living near small bodies of water, drought turned into a real disaster.

Meanwhile, the depths of the sea were filled with a host of species of predatory fish and sharks (Fig. 3). Of course, they were still far from the sharks of modern times, but be that as it may, for the seas of those times they were real killing machines. Their reproduction sometimes reached the point where they had nothing to eat, since they had already exterminated all the living creatures in the area. Then they began to hunt each other, which forced them to acquire all sorts of sharp spines for protection, to grow additional rows of teeth for a more effective attack, and some even began to change the structure of their jaws, turning their heads into all kinds of swords, or even into saws. This entire army of predators, as a result of active reproduction, led to overpopulation of the seas, as a result of which predators of the Carboniferous period, like the current locusts, destroyed all mollusks with relatively soft shells, single corals, trilobites and other inhabitants of water basins.

The danger of dying from the jaws of sharks served as another incentive for the relocation of aquatic life to land. Other species of enamel-scaled lobe-finned fish that lived in freshwater bodies also continued to come to land. They were excellent at jumping along the coast, feeding on small insects. And, in the end, life finally spilled out onto the vast expanses of land.

Rice. 3 - Carboniferous Shark

Ancient amphibians could so far only live at the water's edge, since they still laid eggs in reservoirs for reproduction. Their skeletons were not yet completely bone, but this did not prevent some varieties from growing up to 5 meters in size. As a result, the multiplied stegocephals began to produce varieties. Many were similar in structure to newts and salamanders. Legless snake-like species also appeared. Amphibians are different in that their skull, not counting the mouth, had not 4, but 5 holes - 2 for the eyes, 2 for the ears and 1 in the middle of the forehead - for the parietal eye, which later, as unnecessary, turned into the pineal gland and became an appendage of the brain. The backs of amphibians were naked, and soft scales grew on their bellies.

Flora of the Carboniferous Period(Fig. 4) consisted of ferns, mosses and arthroplastes that had already developed significantly at the beginning. Towards the end of the period, the first horsetails began to appear.

Some lycophytes reached a height of up to 40 m with a 2-meter width of the initial trunk. Their wood did not yet contain growth rings; often it was simply an empty trunk, branched from above by a dense crown. Horsetail leaves sometimes reached a meter in length, and plant buds developed at their ends. At that time, this type of propagation was very justified, and the plants developed with enormous intensity. There were extremely many species of club mosses; there were also club-moss-shaped lepidodendrons, the trunk of which was delimited into rhomboid sections and stiglaria, with hexagonal demarcations. The trunk had no branches at all; only sporongia grew on it for reproduction.

The arthropods gave rise to two main varieties - calamites and cuneate. Wedge-leaved plants grew in coastal areas in water, holding onto it with the help of stem branches in the lower part. Their leaves grew directly from the stem, rarely alternating with kidney-shaped spore-containing structures. They first appeared in the Middle Carboniferous, but could not survive the Permian period, during which they all became extinct.

Rice. 4 - Plants of the Carboniferous period

Calamites had a tree-like structure and reached 30 meters in height. Some of them, in the second half of the Carboniferous period, began to grow lateral branches from the stem, and their wood acquired rings. Many coastal or swampy areas were so overgrown with these plants that they turned into an impassable thicket, the flesh up to the crowns clogged with fallen, dead predecessors. Sometimes dozens of them fell into the swampy slurry, settling there to the bottom and becoming increasingly compressed.

Ferns also multiplied abundantly. In general, during the humid and warm season Carboniferous climate Reproduction using spores gave amazing results. The forests grew to such an extent that the dead plants were no longer able to fall to the ground, there was simply no room for this, and they remained sticking out between living plants. Over time, the interior forest began to resemble a giant tree sponge. The bacteria could no longer cope with such an amount of wood, and therefore the slowly compressed and settling wood remained in its original form, turning into coal concentrate over the years. And new plants, meanwhile, grew right on top of their “compressed” ancestors, which led to gigantic accumulations of anthracite.

By the end of the Carboniferous period, with the appearance of the first horsetails, the earth was covered with grass. Ferns gave rise to tree-like forms, which subsequently began to reproduce by seeds. But not so many gymnosperms are known from the Carboniferous; the competition from the clubmoss, pteridophytes and arthropods was too enormous. But their advantage was that they had an extensive root system, much more efficient and extensive than others. Carboniferous plants, as a result of which they could grow at a considerable distance from the reservoir. Subsequently, these plants began to move further and further away from the water, populating ever larger areas of land.

Also during the Carboniferous, the first mushrooms and bryophyte-type plants began to appear.

Minerals of the Carboniferous Period

The main mineral resource of the Carboniferous period is coal. Over 60 million years, so much woody sedimentary rocks have accumulated that there will be enough “black gold” for many more tens, if not hundreds of years. Also, half of all earthly oil reserves can be attributed to the Carboniferous. Deposits of bauxite (Severo-Onezhsk), copper ores (Dzheskazgan) and lead-zinc deposits (Karatau ridge) were formed in small quantities in certain areas of the earth.

Tsimbal Vladimir Anatolyevich is a plant lover and collector. For many years he has been studying the morphology, physiology and history of plants, and has been conducting educational work.

In his book, the author invites us into the amazing and sometimes mysterious world of plants. Accessible and simple even for an unprepared reader, the book tells about the structure of plants, the laws of their life, and the history of the plant world. In a fascinating, almost detective form, the author talks about many mysteries and hypotheses related to the study of plants, their emergence and development.

The book contains a large number of drawings and photographs by the author and is intended for a wide range of readers.

All drawings and photographs in the book belong to the author.

The publication was prepared with the support of the Dmitry Zimin Dynasty Foundation.

The Dynasty Foundation for Non-Profit Programs was founded in 2001 by Dmitry Borisovich Zimin, honorary president of VimpelCom. The Foundation's priority areas of activity are support for fundamental science and education in Russia, popularization of science and education.

“Library of the Dynasty Foundation” is a project of the Foundation to publish modern popular science books selected by scientific experts. The book you are holding in your hands was published under the auspices of this project.

More detailed information about the Dynasty Foundation can be found at www.dynastyfdn.ru.

On the cover is Ginkgo biloba against the background of a leaf imprint of the probable ancestor of the ginkgos - Psygmophyllum expansum.

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The next period in the history of the Earth is the Carboniferous, or, as it is often called, the Carboniferous. One should not think that, for some magical reason, changing the name of a period entails changes in the flora and fauna. No, the plant worlds of the Early Carboniferous and Late Devonian are not much different. Even in the Devonian, higher plants of all divisions, except angiosperms, appeared. Their further development and flourishing occurred during the Carboniferous period.

One of the important events that occurred during the Carboniferous period was the emergence of different plant communities in different geographical areas. What does this mean?

At the beginning of the Carboniferous, it was difficult to tell the difference between the plants of Europe, America, and Asia. There are some minor differences between the plants of the northern and southern hemispheres. But by the middle of the period, several regions with their own set of genera and species clearly stand out. Unfortunately, there is still a very widespread opinion that the Carboniferous is a time of universally warm, humid climate, when the entire Earth was covered with forests of huge, up to 30 m high, lycophytes - lepidodendrons and sigillaria, and huge tree-like “horsetails” - calamites and ferns. All this luxurious vegetation grew in swamps, where, after death, they formed coal deposits. Well, to complete the picture, we need to add giant dragonflies - meganeuras and two-meter herbivorous centipedes.

It wasn't quite like that. More precisely, this was not the case everywhere. The fact is that in the Carboniferous, as now, the Earth was the same spherical and also rotated around its axis and revolved around the Sun. This means that even then on Earth there was a belt of hot tropical climate along the equator, and closer to the poles it was cooler. Moreover, in the sediments of the end of the Carboniferous in the southern hemisphere, undoubted traces of very powerful glaciers were found. Why is it that even in textbooks we are still told about a “warm and wet swamp”?

This idea of ​​the Carboniferous period developed back in the 19th century, when paleontologists and, in particular, paleobotanists knew fossils only from Europe. And Europe, like America, was precisely in the tropics during the Carboniferous period. But judging the flora and fauna by only one tropical zone, to put it mildly, is not entirely correct. Imagine that some paleobotanist, after many millions of years, having excavated the remains of the current vegetation of the tundra, will give a report on the topic “The flora of the Earth in the Quaternary period.” According to his report, it turns out that you and I, dear reader, live in extremely harsh conditions. That the entire Earth is covered with extremely poor flora, consisting mainly of lichens and mosses. Only here and there can unfortunate people stumble upon a dwarf birch and rare blueberry bushes. After describing such a bleak picture, our distant descendant will certainly conclude that a very cold climate prevailed everywhere on Earth, and will decide that the reason for this is the low content of carbon dioxide in the atmosphere, low volcanic activity, or, in extreme cases, some another meteorite that shifted the earth's axis.

Unfortunately, this is the usual approach to the climates and inhabitants of the distant past. Instead of trying to collect and study samples of fossil plants from different regions of the Earth, find out which of them grew at the same time, and analyze the data obtained, although, of course, this is difficult and requires a significant investment of effort and time, people strive to disseminate that knowledge , which he obtained by observing the growth of an indoor palm tree in the living room, throughout the history of plants.

But we still note that in the Carboniferous period, around the end of the Early Carboniferous, scientists already distinguished at least three large areas with different vegetation. This is a tropical region - Euramerian, northern extratropical - Angara region or Angarida and southern extratropical - Gondwana region or Gondwana. On the modern world map, Angarida is called Siberia, and Gondwana is the united Africa, South America, Antarctica, Australia and the Hindustan Peninsula. The Eurasian region is, as the name implies, Europe together with North America. The vegetation of these areas varied greatly. So, if spore plants dominated in the Euramerian region, then in Gondwana and Angarida, starting from the middle of the Carboniferous, gymnosperms dominated. Moreover, the differences in the floras of these areas increased throughout the Carboniferous and early Permian periods.

What other important events occurred in the plant kingdom of the Carboniferous period? It is necessary to note the appearance of the first conifers in the mid-Carboniferous. When we talk about conifers, our usual pine and spruce trees automatically come to mind. But the Carboniferous conifers were a little different. These were apparently low trees, up to 10 meters; in appearance they were slightly reminiscent of modern Araucaria. The structure of their cones was different. These ancient conifers probably grew in relatively dry places, and descended from... it is still unknown what ancestors. Again, the accepted view of almost all scientists on this issue is that conifers descended from the cordaites. Cordaites, which apparently appeared at the beginning of the Carboniferous period, and also originated from an unknown source, are very interesting and peculiar plants (Fig. 8). These were trees with leathery, lanceolate leaves collected in bunches at the ends of the shoots, sometimes very large, up to a meter long. The reproductive organs of cordaites were long thirty-centimeter shoots with male or female cones sitting on them. It should be noted that the cordaites were very different. There were tall, slender trees, and there were also inhabitants of shallow waters - plants with well-developed aerial roots, similar to modern inhabitants of mangroves. There were also bushes among them.

In the Carboniferous, the first remains of cycads (or cycads) were also found - gymnosperms, not numerous today, but very common in the Mesozoic era following the Paleozoic.

As you can see, the future “conquerors” of the Earth - conifers, cycads, some pteridosperms existed for a long time under the canopy of coal forests and accumulated strength for a decisive offensive.

You certainly noticed the name “seed ferns”. What kind of plants are these? After all, if there are seeds, it means the plant cannot be a fern. That's right, this name may not be very good. After all, we don’t call amphibians “fish with legs.” But this name very well shows the confusion that the scientists experienced when they discovered and studied these plants.

This name was proposed at the beginning of the 20th century by the outstanding English paleobotanists F. Oliver and D. Scott, who, while studying the remains of plants of the Carboniferous period, considered ferns, discovered that seeds were attached to leaves similar to the leaves of modern ferns. These seeds sat at the ends of the feathers or directly on the rachis of the leaf, like in the leaves of the genus Alethopteris(photo 22). Then it turned out that most of the plants of the coal forests, which were previously mistaken for ferns, are seed plants. It was a good lesson. Firstly, this meant that in the past there lived plants completely different from modern ones, and secondly, scientists realized how deceptive external signs of similarity can be. Oliver and Scott gave this group of plants the name "pteridosperms", which means "seed ferns". The names of genera with the ending - pteris(translated as feather), which were traditionally given to fern leaves, remained. This is how the leaves of gymnosperms acquired “fern” names: Alethopteris, Glossopteris and many others.

But what was worse was that after the discovery of pteridosperms, all gymnosperms that were not similar to modern ones began to be classified as seed ferns. The peltaspermaceae, a group of plants with seeds attached to an umbrella-shaped disk - peltoid (from the Greek “peltos” - shield) on its lower side, and the keitoniaceae, in which the seeds were hidden in a closed capsule, and even glossopterids, were also included there. In general, if a plant was a seed plant, but did not fit into any of the existing groups, then it was immediately classified as a pteridosperm. As a result, almost the entire huge variety of ancient gymnosperms turned out to be united under one name - pteridosperms. If we follow this approach, then, without a doubt, we must classify both modern ginkgo and cycads as seed ferns. Nowadays, seed ferns are considered by most paleobotanists to be a collective, formal group. However, class Pteridospermopsida still exists. But we will agree to call pteridosperms only gymnosperms with single seeds attached directly to the pinnately dissected fern-like leaf.

There is another group of gymnosperms that appeared in the Carboniferous - glossopterids. These plants covered the expanses of Gondwana. Their remains were found in deposits of the Middle and Late Carboniferous, as well as the Permian, on all southern continents, including India, which was then in the southern hemisphere. We will talk about these peculiar plants in more detail a little later, since their heyday is the Permian period following the Carboniferous.

The leaves of these plants (photo 24) were similar, at first glance, to the leaves of Euramerian cordaites, although in the Angara species they are usually smaller in size and differ in microstructural characters. But the reproductive organs differ radically. In Angara plants, the organs that carried seeds more closely resemble conifer cones, although of a very peculiar type, not found today. Previously, these plants, Voinovskiaceae, were classified as cordaites. Now they are distinguished in a separate order, and in the recent publication “The Great Turning Point in the History of the Plant World” S.V. Naugolnykh even places them in a separate class. Thus, in the department of gymnosperms, along with the already listed classes, such as conifers or cycads, another one appears - Voinovskiaceae. These peculiar plants appeared at the end of the Carboniferous, but grew widely throughout almost the entire territory of the Angarides in the Permian period.

What else needs to be said about the Carboniferous period? Well, perhaps, it got its name for the reason that the main reserves of coal in Europe were formed precisely at this time. But in other places, in particular in Gondwana and Angarida, coal deposits were formed, for the most part, in the following Permian period.

Generally speaking, the flora of the Carboniferous period was very rich, interesting and diverse and certainly deserves a more detailed description. The landscapes of the Carboniferous period must have looked absolutely fantastic and unusual for us. Thanks to artists such as Z. Burian, who depicted the worlds of the past, we can now imagine the forests of the Carboniferous. But, knowing a little more about the ancient plants and climate of those times, we can imagine other, completely “alien” landscapes. For example, forests of small, two to three meters high, slender, straight tree-like mosses on a polar night, not far from the north pole of that time, in the current extreme northeast of our country.

Here is how S. V. Meyen describes this picture in his book “Traces of Indian Grasses”: “A warm Arctic night was approaching. It was in this darkness that the thickets of lycophytes stood.

Strange landscape! It’s hard to imagine it... Along the banks of rivers and lakes stretches a dull brush of sticks of various sizes. Some fell over. The water picks them up and carries them, knocking them into heaps in the creeks. In places the brush is interrupted by thickets of fern-like plants with rounded, feathery leaves... Autumn leaf fall probably hasn’t happened yet. Along with these plants you will never find the bones of any four-legged animal or the wings of an insect. It was quiet in the thicket."

But we still have a lot of interesting things ahead. Let us hurry further, to the last period of the Paleozoic era, or the era of ancient life, to Perm.

In the Devonian, plants and animals were just beginning to develop land; in the Carboniferous, they mastered it. At the same time, an interesting transition effect was observed - plants have already learned to produce wood, but fungi and animals have not yet learned to effectively consume it in real time. Because of this effect, a complex multi-stage process was initiated, as a result of which a significant part of the Carboniferous land turned into vast swampy plains, littered with unrotted trees, where layers of coal and oil formed under the surface of the earth. Most of these minerals were formed during the Carboniferous period. Due to the massive removal of carbon from the biosphere, the oxygen content in the atmosphere more than doubled - from 15% (in the Devonian) to 32.5% (now 20%). This is close to the limit for organic life - at high concentrations of oxygen, antioxidants no longer cope with the side effects of oxygen respiration.

Wikipedia describes 170 genera dating back to the Carboniferous period. The dominant type, as before, is vertebrates (56% of all genera). The dominant class of vertebrates is still lobe-finned fish (41% of all genera), they can no longer be called lobe-finned fish, because the lion's share of lobe-finned fish (29% of all genera) acquired four limbs and ceased to be fish. The classification of Carboniferous tetrapods is very tricky, confusing and contradictory. When describing it, it is difficult to use the usual words “class”, “order” and “family” - small and similar families of Carboniferous tetrapods gave rise to huge classes of dinosaurs, birds, mammals, etc. To a first approximation, the four-legged Carbonifera are divided into two large groups and six small ones. Let's consider them gradually, in descending order of diversity.

Other synapsids, varanopids, were more reminiscent of modern monitor lizards than lizards in their anatomical features. But they had nothing to do with monitor lizards; these are all tricks of parallel evolution. In the Carboniferous they were small (up to 50 cm).

The third group of Carboniferous synapsids is edaphosaurs. They became the first large herbivorous vertebrates, occupying the ecological niche of modern cows for the first time. Many edaphosaurs had a folding sail on their back, allowing them to more effectively regulate body temperature (for example, to warm up, you need to go out into the sun and open the sail). Edaphosaurs of the Carboniferous period reached 3.5 m in length, their mass reached 300 kg.

The last group of Carboniferous synapsids worthy of mention are the sphenacodonts. These were predators who, for the first time in the history of four-legged animals, grew powerful fangs at the corners of their jaws. Sphenacodonts are our distant ancestors; all mammals descended from them. Their sizes ranged from 60 cm to 3 m, they looked something like this:

With this topic of synapsids covered, let’s look at other, less prosperous groups of reptiliomorphs. In second place (4% of all genera) are anthracosaurs - the most primitive reptiliomorphs, possibly the ancestors of all other groups. They did not yet have eardrums in their ears, and as children they may have still been going through the tadpole stage. Some anthracosaurs had a weakly defined caudal fin. The sizes of anthracosaurs ranged from 60 cm to 4.6 m

The third large group of reptiliomorphs is sauropsids (2% of all Carboniferous genera). These were small (20-40 cm) lizards, without quotation marks, in contrast to the lizard-like synapsids. Hylonomus (in the first picture) is the distant ancestor of all turtles, petrolacosaurus (in the second picture) is the distant ancestor of all other modern reptiles, as well as dinosaurs and birds.

To finally expand on the topic of reptiliomorphs, let us mention the strange creature Soledondosaurus (up to 60 cm), which is generally not clear to which branch of reptiliomorphs to be attributed:

So, the topic of reptiliomorphs is covered. Let us now move on to the second large group of Carboniferous tetrapods - amphibians (11% of all genera). Their largest subgroup were temnospondyls (6% of all Carboniferous genera). Previously, they, together with anthracosaurs, were called labyrinthodonts; later it turned out that the unusual structure of teeth in anthracosaurs and temnospondyls was formed independently. Temnospondyls are similar to modern newts and salamanders, the largest reaching a length of 2 m.

The second and last large group of Carboniferous amphibians are the lepospondyls (thin-vertebrates), which include 5% of all genera of the Carboniferous period. These creatures completely or partially lost their limbs and became like snakes. Their sizes ranged from 15 cm to 1 m.

So, all the large thriving groups of tetrapods have already been considered. Let us briefly consider small groups that are almost no different from those described above, but are not closely related to them. These are transitional forms or dead-end branches of evolution. So, let's go. Baphetids:

and other, very small groups:

With this the topic of four-legged animals is finally covered, let’s move on to fish. Lobe-finned fishes (namely fish, excluding tetrapods) make up 11% of all genera in the Carboniferous, with the breakdown approximately as follows: 5% are tetrapodomorphs that did not go through the development of land, another 5% are coelacanths, and the remaining 1% are pitiful remnants of Devonian diversity lungfish. In the Carboniferous, tetrapods replaced lungfishes from almost all ecological niches.

In the seas and rivers, lobe-finned fish have been greatly replaced by cartilaginous fish. Now they are no longer just a few births, as in the Devonian, but 14% of all births. The largest subclass of cartilaginous fish is elasmobranchs (9% of all genera), the largest superorder of elasmobranchs is sharks (6% of all genera). But these are not at all the same sharks that swim in modern seas. The largest order of Carboniferous sharks is eugeneodonts (3% of all genera)

The most interesting feature of this order is the dental spiral - a long soft projection on the lower jaw, studded with teeth and usually curled into a spiral. Perhaps during a hunt, this spiral shot out of the mouth like a “mother-in-law’s tongue,” and either grabbed the prey or cut it like a saw. Or maybe it was intended for something completely different. However, not all eugeneodonts have a dental helix expressed in all its glory; some eugenodonts, instead of a dental helix, had dental arches (one or two), which are not at all clear why they are needed. A typical example is edestus

Eugeneodonts were large fish - from 1 to 13 m,Campodusbecame the largest animal of all time, breaking the Devonian record of Dunkleosteus.

However, the helocoprion was only a meter shorter

The second large order of Carboniferous sharks is the symmoriids (2% of all genera). This includes stethacanthus, already familiar to us from the Devonian review. Symmoriids were relatively small sharks, no more than 2 m in length.

The third order of Carboniferous sharks that deserves mention is the xenacanthids. These were moderately large predators, from 1 to 3 m:

An example of a Late Carboniferous xenocanthus is pleuracanthus, one of the most studied representatives of ancient sharks. These sharks were found in the fresh waters of Australia, Europe and North America; complete remains were dug up in the mountains near the city of Pilsen. Despite their relatively small size - 45-200 cm, usually 75 cm - pleuracanths were formidable enemies for acanthodias and other small fish of that time. Attacking a fish, the pleuracanth instantly destroyed it with its teeth, each of which had two diverging points. Moreover, they were believed to hunt in packs. According to scientists, pleuracanths laid eggs, connected by a membrane, in shallow corners of small reservoirs rich in sunlight. Moreover, both freshwater and brackish water reservoirs. Pleuracanths were also found in the Permian - their numerous remains were found in the Permian strata of the Central and Western

Pleuracanth

Europe. Then pleuracanths had to coexist with many other sharks adapted to the same living conditions.

It is impossible to ignore one of the most remarkable ctenocanthus sharks, which is also the property of the Carboniferous. I mean bandringa. The body of this shark did not exceed 40 cm in length, but almost half of it was occupied by... the snout, the rostrum! The purpose of such an amazing invention of nature is unclear. Maybe the bandringas used the tip of their snout to probe the bottom in search of food? Maybe, like on a kiwi's beak, the nostrils were located at the end of the shark's rostrum and helped it sniff everything around, since they had poor eyesight? No one knows this yet. The bandringa's occipital spine was not found, but it most likely had one. Amazing long-nosed sharks lived in both fresh and salt waters.

The last ctenocanthus became extinct in the Triassic period.

This concludes the topic of carbon sharks. Let us mention a few more elasmobranch fishes that are similar to sharks, but are not them; these are focal points of parallel evolution. Such “pseudo-sharks” include 2% of all Carboniferous genera; these were mainly small fish - up to 60 cm.

Now let's move on from elasmobranchs to the second and last large subclass of cartilaginous fish - whole-headed fish (5% of all Carboniferous genera). These are small fish, similar to modern chimeras, but more diverse. Chimeras also belong to the whole-headed species and already existed in the Carboniferous.

This concludes the topic of cartilaginous fish. Let's briefly look at the two remaining classes of fish from the Carboniferous period: ray-finned fish (7-18 cm):

and acanthodes (up to 30 cm):

Both of these classes vegetated quietly in carbon fiber. As for armored fish and almost all jawless fish, they became extinct at the end of the Devonian and, thus, the review of fish of the Carboniferous period is completed. Let us briefly mention that in the Carboniferous there were here and there primitive chordates and hemichordates that did not have a true backbone, and let us move on to the next large type of Carboniferous animals - arthropods (17% of all genera).

The main news in the world of arthropods is that during the transition from the Devonian to the Carboniferous, trilobites almost became extinct, leaving only one small detachment that continued their miserable existence until the next great extinction at the end of the Permian period. The second big news was the appearance of insects (6% of all genera). The abundance of oxygen in the air allowed these creatures not to form a normal respiratory system, but to use poor tracheas and feel no worse than other terrestrial arthropods. Contrary to popular belief, the diversity of insects in the Carboniferous period was small, most of them were very primitive. The only large order of Carboniferous insects are dragonflies, the largest of which (Meganeur, shown in the picture) reached a wingspan of 75 cm, and in weight approximately corresponded to a modern crow. However, most Carboniferous dragonflies were much smaller.