The Paleozoic era is the Carboniferous period. Carboniferous period, animals of the Carboniferous period

Once upon a time, the waters of the World Ocean covered the entire planet, and the land appeared on its surface as separate islands. Scientists indicate these islands with great accuracy. How? Through coal seams scattered throughout the globe, even in polar countries. Each area where coal is found was then an island, around which the waves of the World Ocean boiled. By the extent of the coal deposits, one can determine the approximate size of the forests that covered the islands. And by the thickness of the coal seams they know how long they grew here. Millions of years ago, these island forests captured enormous reserves of energy from the sun's rays and buried them with them in the stone graves of the Earth.

They did a great job, these primeval forests. Coal reserves around the globe amount to trillions of tons. It is believed that with the extraction of two billion tons per year, humanity will be provided with fossil coals for millennia! And Russia ranks first in the world in terms of coal reserves.

Natural engravings imprinted by nature itself, depicting the vegetation of forests of past periods, have been preserved in the ground. Pieces of coal, shale, and brown coal often contain strikingly clear imprints of plants that are their contemporaries.

Sometimes nature preserved parts of plants in amber; inclusions of animal origin were also found in it. Amber was highly valued in ancient world as decoration. Caravans of ships followed him to the shores of the foggy Baltic. But what is amber itself? The Roman writer and naturalist Pliny conveys a touching Greek legend about its origin: the frozen tears of girls, daughters of Apollo, inconsolably mourning the death of their brother Phaethon...

The origin of amber was not known even in the Middle Ages, although the demand for it increased greatly. He used it to make rich monastic rosaries.

The secret of amber was revealed by M. V. Lomonosov: “Amber is a product of the plant kingdom.” This is the frozen resin of coniferous trees that once grew in the places where amber is now mined.

Remains of pollen and spores of ancient plants were discovered in rock layers using a microscope.

Finds from different layers are compared with each other and with modern plants and thus studied flora distant times. “Nature reveals many underground secrets in this way,” - this is how one can say about this in the words of M. V. Lomonosov.

Most often they are not at all similar to our plants, sometimes they resemble them to some extent and yet are sharply different. It was a different plant world, and only sometimes, mainly in tropical countries, are plants found - a living reminder of ancient times.

From the prints it is possible to reconstruct forest landscapes of the Carboniferous period and later. “We can even recreate these landscapes with such completeness,” writes German researcher Karl Müller in the book “The World of Plants. An experience of space botany,” as if nature had handed over to us a collection of all the plants of that time.”

… The forests of the Carboniferous period rose straight out of the water; they occupied low-lying shores and swampy plains inside the islands. Nothing like modern forests any latitudes of the earth with their life forms and paints.

In the middle of the Carboniferous period, giant forms of clubmosses developed - lepidodendrons and sigillaria, whose powerful trunks, up to two meters in diameter, reached 20-30 meters in height. They have narrow bristle-like leaves scattered along the trunk. Somewhat lower were giant horsetails - calamites.

Lepidodendrons and sigillaria settled on muddy banks, where other plants without such branched roots with vertical outgrowths for breathing were suffocating.

Real ferns with wide pinnately divided plates - fronds - also appeared. But their position was much more modest than that of club mosses and horsetails. They did not produce such gigantic forms, but they surpassed mosses and horsetails in diversity: from tree-like to delicate herbaceous. Their thin dark brown trunks with thickenings and scars from fallen leaves, overgrown with green mosses, raised bunches of huge, beautifully dissected leaves, like magnificent fans, to the then eternally gloomy sky. Climbing species of ferns entwined the trunks of tree species and mixed below with the grassy cover of ferns.

Above the gentle arch of the green canopy stretched a dark sky with heavy clouds. Frequent showers, thunderstorms, evaporation, warm and even temperatures created conditions extremely favorable for the development of ferns. Luxurious bush-like forms grew under the tree ferns. The soil, where mosses and algae had rotted, was covered with herbaceous ferns. But these forests presented a monotonous and dull picture: only about 800 plant species have been discovered so far, including more than 200 species of ferns.

In prints on coal there are often traces of real trees - cordaites, the ancestors of gymnosperms. This tall trees with long, belt-shaped leaves collected in dense bunches. Cordaites grew on the edges of swamps, preferring them to muddy swamps.

In the southeast of North America, on the Mississippi River, swamp cypress forests rose in the peat bogs flooded by its waters. Trees felled by a storm or rotted over time fell to the ground and, together with ferns and mosses, slowly decomposed with poor air access.

There was silence in the forests. Only occasionally will a huge, clumsy amphibian rustle among the ferns. It crawls slowly under the foliage, hiding from the daylight. Yes, somewhere in the heights a rare insect will fly - a novelty of that period, with wings up to 70 centimeters in span. No birds singing, no grasshoppers chirping.

Before the appearance of ferns and mosses, there were no fertile soils on Earth. There were clays and sands, but they were not yet soil in our modern understanding, because they did not contain humus. In coal forests, the accumulation of plant residues and the formation of a dark layer - humus - begins. Together with clays and sands, it gave rise to fertile soils.

In brown coal deposits there are whole trees, with bark and leaves. A piece of fossil coal under a microscope told about anatomical structure these plants. It turned out to be the same as that of modern conifers. Consequently, brown coal was formed later, when conifers took a dominant position on Earth, pushing aside pteridophytes. This could happen with an increase in land mass and climate change towards greater dryness: from island to continental.

Above the thick layers of coal in our largest coal basins - Kuznetsk, Donetsk, Moscow Region and others - the lights of big cities sparkle, the laughter of children and the songs of youth are heard, trains run, airplanes fly. There is an inexhaustible search by man for a better life... And once upon a time there were marshy shores of small sea bays, covered with the vegetation of the humid tropics. This was learned from a microscopic section of petrified wood, made in the form of a thin section. Petrified trunks from the Donetsk basin turned out to lack the growth rings typical of northern trees.

Such rings are formed in the wood of modern trees temperate latitudes because they grow vigorously in spring and summer, but stop growing in winter. And in the cross section you can immediately distinguish the wide summer layers of wood from the narrow winter ones. The wood of many tropical plants does not have growth rings. This means that in those distant times, in the territory of the modern Donetsk basin, there was even warm and humid weather all year round, as in humid equatorial forests.

In the northern regions of the USSR, in ancient stone layers of the earth, the remains of laurels, magnolias, cypresses, that is, the Mediterranean flora, are found. On Spitsbergen, where only small herbs and shrubs currently grow, remains of plane trees and walnuts are found.

Lush palm trees once grew in the lower reaches of the Volga. On the shores of modern Baltic Sea Mediterranean vegetation flourished. Tree ferns, laurels, famous mammoth trees, palm trees - everything that we now see in botanical gardens grew under our sky.

Greenland is even more amazing. Under solid ice magnolia, oaks, and grapes were found in the ground. In India, on the contrary, the flora of the Carboniferous period was characterized by low growth, coarse dense leaves, and the development of shrubs and grasses. And this is evidence of a colder and drier climate.

“In the northern regions in ancient times there were great heat waves,” wrote M.V. Lomonosov, “where elephants could be born and reproduce, as well as ordinary plants near the equator, it was possible to stay.”

What explanation does science give for these amazing facts? Once upon a time, all the continents made up a single continent, which then split into parts that moved apart into different sides. The movement of continents caused a shift in the earth's axis. Together with it, the positions of the points of the North and Skin poles lying on it changed, and, consequently, the equator.

If we agree with this theory, then in the Carboniferous period the equator did not pass where it passes now, but further north: through Central Europe and the Caspian Sea. And the entire Donetsk basin was in a wet zone equatorial forests, which is confirmed by its fossil vegetation. The subtropics went far to the north, and the point of the North Pole then lay somewhere off the eastern coast of America. On the continents of the Southern Hemisphere - Australia, Africa, South America, which were not yet separated at that time, the climate was cold. This explains the absence of tropical vegetation in the Carboniferous terrestrial strata on the continents of the Southern Hemisphere.

It is believed that the Carboniferous forests grew more than two hundred million years ago and that in the next, Permian, period, the dominance of ferns ended. Carboniferous forests died for various reasons. In some places, the sea flooded forests on the sunken parts of the earth's surface. Sometimes they died, captured by swamps.

In many cases, climate change has caused their demise. The sun in their heyday never burned with its rays: they were softened by heavy clouds hanging low over the forest. Now the sky became cloudless and the sun sent burning rays to the plants. For ferns these conditions were unbearable, and they became noticeably smaller, taking refuge only in the shade of the more hardy gymnosperms.

With their death, the Middle Ages began for the forests of the Earth, leaving their traces in the stone book of our planet.

The climate on Earth, in connection with the processes of mountain building, became more diverse. Mountain ranges stood as a wall in the path of moist sea winds and fenced off the interior spaces of the continents, turning them into deserts.

On the territory of the European part of the USSR, a majestic mountain range - the Ural - rose from the bottom of what was then the Ural Sea. Now we know it as decrepit, dilapidated, but in the days of its youth the Urals were mighty, and eternal snow crowned its peaks. In place of the Donetsk Sea, a mountain range appeared - Donetsk, completely smoothed by time.

Central Europe gradually moved from the equator zone to the zone of subtropical steppes and deserts, and then to the temperate zone. In a drier and colder climate, people from the cold countries of the Southern Hemisphere, where warming has begun, felt great.

In dry and hot climates early Middle Ages The most ancient coniferous araucaria and interesting gymnosperms - ginkgo - developed. This plant looks ordinary broadleaf tree. But its “leaf” is a wide bipartite fan-shaped needle with a forked arrangement of veins. There were no longer any lepidodendrons, no sigillarias, no cordaites; Only the seed ferns survived.

The climate has changed again: it has become wetter and milder. Along the shores of the tropical seas that covered the southern regions of the USSR and washed the Far East and Turkestan, gymnosperm forests grew luxuriantly, especially the so-called cycads and bennetites. But they did not remain masters of the situation for long, and now only fossil finds testify to them. In Mexico they found a layer 600 meters thick; at one time it was a whole forest of Bennettites. We found their remains in the vicinity of Vladivostok and Turkestan.

Darwin encountered fossilized conifers in the Cordillera at an altitude of more than 2000 meters; eleven of them stood in the form of trees, although petrified, and thirty to forty others had already turned into white lime spar, and their stumps stuck out above the ground. Once upon a time they extended their branches over the very ocean, which at that time approached the foot of the Cordillera. They were nurtured by volcanic soil that rose above sea level. Then the area became the seabed again and the waves rolled over the tops of the flooded trees. The sea dragged sand, gravel, pebbles onto them, and lavas from underwater volcanoes lay on top. Hundreds of millennia passed... The seabed rose again and was exposed. Valleys and ravines cut it apart. An ancient grave was opened, and the hidden monuments of the past appeared on the surface of the earth. The soil that once nourished them, and they themselves turned to stone.

Many conifers have survived to this day, having endured violent upheavals of mountain formations, climate changes and, most importantly, surviving even with the advent of the most advanced flora - angiosperms.

In just half a million years, this group of plants captured the entire globe from the poles to the equator, settled everywhere and gave rise to the highest number of species in the entire long history of plants on Earth.

From a geological point of view, half a million years is a short period. The victory of the angiosperms, compared with the entire history of vegetation over hundreds of millions of years, and perhaps more than a billion, is like a flood that suddenly engulfed our entire planet. Like an explosion of new plant species!

But what ensured such a victory for angiosperms? Many reasons: amazing flexibility in adapting to different conditions life, different climates, soils, temperatures. The appearance and development simultaneously with angiosperms of pollinating insects: butterflies, flies, bumblebees, bees, beetles. The birth of a perfect flower with a green calyx and a bright corolla, with a delicate aroma, with ovules protected by the ovary.

But the main thing is different. The fact is that angiosperms on land fulfill their cosmic role in nature better than all other green plants. Their crown, branches, leaves are widely spread in the air and receive solar energy and carbon dioxide on several floors. No other group of plants had such capabilities.

Green algae in the world's oceans, first caught sunbeam using chlorophyll grains, multicellular algae, mosses and lichens, ferns, gymnosperms, angiosperms - all the links of the great green chain on Earth eternally serve a single purpose: to catch the sun's ray. But angiosperms improved in this direction better than other plants.

We have turned over only a few pages from the chronicle, but they are also vivid witnesses to the panorama of forests on our planet, eternally moving in space and time.

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 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, 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. 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... >>>

From 360 to 286 million years ago.
At the beginning of the Carboniferous period (Carboniferous), most of the earth's land was collected into two huge supercontinents: Laurasia in the north and Gondwana in the south. During the Late Carboniferous, both supercontinents steadily moved closer to each other. This movement pushed up new mountain ranges that formed along the edges of the plates earth's crust, and the edges of the continents were literally flooded by streams of lava erupting from the bowels of the Earth. The climate cooled noticeably, and while Gondwana was “swimming” through South Pole, the planet has experienced at least two glacial periods.

In the Early Carboniferous, the climate over most of the earth's land surface was almost tropical. Huge areas were occupied by shallow coastal seas, and the sea constantly flooded the low-lying coastal plains, forming vast swamps there. In this warm and humid climate, virgin forests of giant tree ferns and early seed plants became widespread. They released a lot of oxygen, and by the end of the Carboniferous, the oxygen content in the Earth's atmosphere almost reached modern levels.
Some trees growing in these forests reached 45 m in height. The plant mass increased so quickly that the invertebrate animals living in the soil simply did not have time to eat and decompose the dead plant material in time, and as a result it became more and more numerous. In the humid climate of the Carboniferous period, this material formed thick deposits of peat. In swamps, peat quickly sank under water and became buried under a layer of sediment. Over time, these sedimentary layers turned into coal-bearing strata
cabbage soup deposits of sedimentary rocks, layered with coal, formed from the fossilized remains of plants in peat.

Reconstruction of a coal swamp. It is home to many large trees, including sigillaria (1) and giant club mosses (2), as well as dense stands of calamites (3) and horsetails (4), ideal habitat for early amphibians such as Ichthyostega (5) and Crinodon (6). . Arthropods are swarming all around: cockroaches (7) and spiders (8) scurry in the undergrowth, and the air above them is plowed by giant meganeura dragonflies (9) with a wingspan of almost a meter. Because of rapid growth Such forests accumulated a lot of dead leaves and wood, which sank to the bottom of the swamps before they had time to decompose, and over time turned into peat, and then into coal.
Insects are everywhere

At that time, plants were not the only living organisms that colonized land. Arthropods also emerged from the water and gave rise to a new group of arthro-nodes, which turned out to be extremely viable, insects. From the moment insects first appeared on the stage of life, their triumphal march began, but
planet. Today there are at least a million species of insects known to science on Earth, and, according to some estimates, about 30 million more species remain to be discovered by scientists. Truly our time could be called the era of insects.
Insects are very small and can live and hide in places inaccessible to animals and birds. The bodies of insects are designed in such a way that they easily master any means of movement - swimming, crawling, running, jumping, flying. Their hard exoskeleton is the cuticle (consisting of a special substance - chitin) -
passes into the oral part, capable of chewing hard leaves, sucking plant juices, and also piercing the skin of animals or biting prey.

HOW COAL IS FORMED.
1. The coal forests grew so quickly and lushly that all the dead leaves, branches and tree trunks that accumulated on the ground simply did not have time to rot. In such “coal swamps,” layers of dead plant remains formed deposits of water-soaked peat, which was then compressed and turned into coal.
2. The sea advances on land, forming deposits on it from the remains of marine organisms and layers of silt, which subsequently turn into clay shales.
3. The sea recedes, and rivers deposit sand on top of the shale, from which sandstones are formed.
4. The area becomes more swampy, and silt is deposited on top, suitable for the formation of clayey sandstone.
5. The forest grows back, forming a new coal seam. This alternation of layers of coal, shale and sandstone is called a coal-bearing strata

Great Carboniferous Forests

Among the lush vegetation of the Carboniferous forests, huge tree ferns, up to 45 m high, with leaves predominated longer than a meter. In addition to them, giant horsetails, club mosses and recently emerged seed-bearing plants grew there. The trees had an extremely shallow root system, often branching above the surface
soil, and they grew very close to each other. The area was probably littered with fallen tree trunks and piles of dead branches and leaves. In these impenetrable jungle the plants grew so quickly that the so-called ammonifiers (bacteria and fungi) simply did not have time to cause decay of organic remains in the forest soil.
In such a forest it was very warm and humid, and the air was constantly saturated with water vapor. The many creeks and swamps provided ideal spawning grounds for countless insects and early amphibians. The air was filled with the buzzing and chirping of insects - cockroaches, grasshoppers and giant dragonflies with a wingspan of almost a meter, and the undergrowth was teeming with silverfish, termites and beetles. The first spiders had already appeared, and numerous centipedes and scorpions were scurrying across the forest floor.

Fragment of a fossilized Aletopteris fern from a coal-bearing strata. Ferns thrived in the damp, wet Carboniferous forests, but they were ill-adapted to the drier climate that developed during the Permian period. When germinating, fern spores form a thin, fragile plate of cells - prothallium, in which male and female reproductive organs are developed over time. Prothallium is extremely sensitive to moisture and dries quickly. Moreover, male reproductive cells, sperm secreted by prothallium, can reach the female egg only through a film of water. All this interferes with the spread of ferns, forcing them to adhere humid environment habitats where they are found to this day
Plants of coal swamps

The flora of these huge forests would seem very strange to us.
Ancient clubmoss plants, relatives of modern clubmosses, looked like real trees - 45 m high. Heights of up to 20 m reached the top of giant horsetails, strange plants with rings of narrow leaves growing directly from thick jointed stems. There were also ferns the size of good trees.
These ancient ferns, like their living descendants, could only exist in humid areas. Ferns reproduce by producing hundreds of tiny spores in a hard shell, which are then carried by air currents. But before these spores can develop into new ferns, something special must happen. First, tiny fragile gametophytes (plants of the so-called sexual generation) grow from the spores. They, in turn, produce small calyces containing male and female reproductive cells (sperm and eggs). To swim to the egg and fertilize it, sperm need a film of water. And only then can a new fern, the so-called sporophyte (asexual generation) develop from the fertilized egg life cycle plants).

Meganeura were the largest dragonflies ever to live on Earth. Moisture-saturated coal forests and swamps provided shelter for many smaller flying insects, which served as easy prey for them. The huge compound eyes of dragonflies give them almost all-round visibility, allowing them to detect the slightest movement of a potential victim. Perfectly adapted to aerial hunting, dragonflies have undergone very little changes over the past hundreds of millions of years.
Seed plants

Fragile gametophytes can only survive in very wet places. However, towards the end of the Devonian period, seed ferns appeared, a group of plants that managed to overcome this disadvantage. Seed ferns were in many ways similar to modern cycads or cyathea and reproduced in the same way. Their female spores remained on the plants that gave birth to them, and there they formed small flask-shaped structures (archegonia) containing eggs. Instead of floating sperm, seed ferns produced pollen that was carried by air currents. These pollen grains germinate into female spores and release male reproductive cells into them, which then fertilize the egg. Now plants could finally colonize the arid regions of the continents.
The fertilized egg developed inside a cup-shaped structure called the ovule, which then developed into a seed. The seed contained reserves of nutrients, and the embryo could quickly germinate.
Some plants had huge cones up to 70 cm long, which contained female spores and formed seeds. Now plants could no longer depend on water, which previously required male reproductive cells (gametes) to reach eggs, and the extremely vulnerable gametophytic stage was excluded from their life cycle.

Warm Late Carboniferous swamps abounded in insects and amphibians. Butterflies (1), giant flying cockroaches (2), dragonflies (3) and mayflies (4) fluttered among the trees. Giant two-legged centipedes feasted in the rotting vegetation (5). Labiopods hunted on the forest floor (6). Eogyrinus (7) is a large amphibian, up to 4.5 m long, which may have hunted like an alligator. And the 15-centimeter microbrachia (8) fed on the smallest animal plankton. The tadpole-like Branchiosaurus (9) had gills. Urocordilus (10), Sauropleura (1 1) and Schincosaurus (12) looked more like newts, but the legless dolichosoma (13) looked a lot like a snake.
Time for amphibians

The bulging eyes and nostrils of the first amphibians were located at the very top of the wide and flat head. This “design” turned out to be very useful when swimming on the water surface. Some of the amphibians may have lay in wait for their prey while half submerged in water, in the manner of today's crocodiles. Perhaps they were like giant salamanders. These were formidable predators with hard and sharp teeth with which they grabbed their prey. A large number of their teeth are preserved as fossils.
Evolution soon gave rise to many different forms of amphibians. Some of them reached 8 m in length. The larger ones still hunted in the water, and their smaller counterparts (microsaurs) were attracted by the abundance of insects on land.
There were amphibians with tiny legs or no legs at all, something like snakes but without scales. They may have spent their entire lives buried in the mud. Microsaurs looked more like small lizards with short teeth, with which they split the covers of insects.

A Nile crocodile embryo inside an egg. Such eggs, resistant to drying out, protect the embryo from shocks and contain enough food in the yolk. These properties of the egg allowed reptiles to become completely independent of water.
First reptiles

Towards the end of the Carboniferous period, a new group of four-legged animals appeared in the vast forests. Basically, they were small and in many ways similar to modern lizards, which is not surprising: after all, these were the first reptiles on Earth. Their skin, more waterproof than that of amphibians, gave them the opportunity to spend their entire lives out of water. There was plenty of food for them: worms, centipedes and insects were at their complete disposal. And after a relatively short time, more large reptiles, which began to eat their smaller relatives.

Everyone has their own pond

The need for reptiles to return to water to reproduce has disappeared. Instead of laying soft eggs that hatched into floating tadpoles, these animals began laying eggs in a hard, leathery shell. The babies that hatched from them were exact miniature copies of their parents. Inside each egg there was a small bag filled with water, where the embryo itself was located, another bag with the yolk, which it fed on, and, finally, a third bag where feces accumulated. This shock-absorbing layer of liquid also protected the embryo from shock and damage. The yolk contained a lot of nutrients, and by the time the baby hatched, it no longer needed a pond (instead of a pouch) to mature: it was already old enough to get its own food in the forest.
rum If you moved them up and down, you could warm up even faster - let's say, like you and I warm up when running in place. These "flaps" became larger and larger, and the insect began to use them to glide from tree to tree, perhaps to escape predators such as spiders.

FIRST FLIGHT
Carboniferous insects were the first creatures to take to the air, and they did this 150 million years before birds. Dragonflies were the pioneers. They soon became the “kings of the air” of the coal swamps. The wingspan of some dragonflies reached almost a meter. Butterflies, moths, beetles and grasshoppers then followed suit. But how did it all start?
In the damp corners of your kitchen or bathroom, you may have noticed small insects called scale insects (right). There is a species of silverfish with a pair of tiny flap-like plates protruding from their bodies. Perhaps some similar insect and became the ancestor of all flying insects. Maybe it spread these plates in the sun to quickly warm up in the early morning.

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 can no longer cope with side effects oxygen breathing.

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.

The first large group is reptiliomorphs (13% of all genera). These animals were more terrestrial than water image life (although not all), many of them did not spawn, but laid eggs with a strong shell, and these eggs hatched not into tadpoles, but into fully formed reptiliomorphs that needed to grow, but no longer needed to radically change their body structure. By the standards of the Carboniferous period, these were very advanced animals, they already had normal nostrils and ears (not auricles, but hearing aids inside the head). The most numerous subgroup of reptiliomorphs are synapsids (6% of all genera). Let's start looking at synapsids with their largest group, the ophiacodonts. These were moderately large (50 cm – 1.3 m) “lizards”, not particularly remarkable. The word “lizards” is put in quotation marks because they have nothing to do with modern lizards, the resemblance is purely external. Here, for example, is the smallest of the ophiacodonts, Archaeotiris:

Other synapsids - varanopids - had anatomical features that were more reminiscent of modern monitor lizards than lizards. 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 teeth at the corners of their jaws. powerful fangs. 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's move on to the second one now. large group carboniferous tetrapods – amphibians (11% of all genera). Their largest subgroup were temnospondyls (6% of all Carboniferous genera). Previously, together with anthracosaurs, they 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 the 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. Largest subclass cartilaginous fish– 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. Most large squad Carboniferous sharks – 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 generally not 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 are believed to have hunted 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 the 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, mostly small fish– up to 60 cm.

Now let's move from elasmobranchs to the second and last large subclass of cartilaginous fish - whole-headed (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.

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 You can find information about the Dynasty Foundation 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. The Carboniferous period accounts for their further development and blossoming.

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. Except that 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 food along the equator. tropical climate, and closer to the poles it is cooler. Moreover, in the deposits of the late Carboniferous in 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 to judge 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 “Flora of the Earth Quaternary period" According to his report, it turns out that you and I, dear reader, live in extreme 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 modern map world Angarida is called Siberia, and Gondwana is united Africa, South America, Antarctica, Australia and the Indian subcontinent. The Eurasian region is, as the name implies, Europe together with North America. The vegetation of these areas varied greatly. So, if the Euramerian region was dominated spore plants, then in Gondwana and Angarida, starting from the middle of the Carboniferous - gymnosperms. Moreover, the difference in the floras of these areas increased throughout the Carboniferous and at the beginning of the Permian period.

Rice. 8. Cordaite. Possible ancestor of conifers. Carboniferous period.

What other important events originated 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 coniferous plants, 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 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 translated 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.

Photo 22. Imprints of leaves of gymnosperms Alethopteris (aletopteris) and Neuropteris (neuropteris). Carboniferous period. Rostov region.

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 very peculiar type, not found today. Previously, these plants, Voinovskiaceae, were classified as cordaites. Now they are allocated 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.

Photo 23. Fossil seeds of Voinovskie. Lower Permian. Cis-Urals.

Photo 24. Imprints of Voinovskiy leaves.

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 a bone of any four-legged animal or the wing of an insect. It was quiet in the thicket."

But we still have a lot of interesting things ahead. Let's hurry on further, to last period the Paleozoic era, or the era of ancient life, - in the Permian.

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