Mesozoic period. Mesozoic era

The Carboniferous By the end of the Devonian, the flowing waters had eroded and greatly flattened the mountain ranges that rose along the ocean coasts. Wet sea ​​winds began to freely sweep over the continents. The sea began to attack the land again. shallow

Permian period At the end of the last century, much in the history of life on Earth was still unclear and mysterious. One of the great mysteries was the Permian - following the Carboniferous - period, the last period of the ancient era. Scientists have established a slender

Chapter IX From the greatest extinction to the Mesozoic realignment (Triassic, Jurassic and Cretaceous periods: 248 - 65 million years ago) I am an ichthyosaur, plesiosaur, pliosaurus, ferocious; I cut the water; streamlined, silent, fast and light, like a shadow of blue - the toothy blue itself! Bye

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The origin of birds: "ornithization" (end of the Jurassic - Cretaceous period) Few of the ancient inhabitants of the Earth can compare in popularity with the famous Archeopteryx, eight skeletons of which were found in Germany in Late Jurassic deposits. This creature

The Cretaceous period is considered the longest period of the Mesozoic, as it lasted about 79 million years.

Geography

The divided parts of the Pangea supercontinent drifted apart. The Tethys Ocean still separated the northern continent of Laurasia from southern Gondwana. The North and South Atlantic were still inaccessible. By the middle of the period, ocean levels were much higher; most of the land known to us was still under water. By the end of the period, the continents acquired outlines close to modern ones. Africa and South America took on their distinctive forms; but India had not yet collided with Asia, and Australia remained part of Antarctica.

Climate

During the Cretaceous period, climate conditions on Earth became warmer. It was colder at the poles. Fossils of tropical plants and ferns support this assumption.

Animals lived everywhere, even in colder areas. For example, fossil hadrosaurs dating back to the Late Cretaceous have been found in Alaska.

When the asteroid hit, the world likely experienced a so-called "nuclear winter" when dust particles blocked many of the sun's rays from reaching the land surface.

Vegetable world

One of hallmarks Cretaceous period was the development of flowering plants. The oldest angiosperm fossil Archaefructus liaoningensis- was found in China. This plant is believed to be most similar to modern black pepper and is at least 122 million years old.

It used to be that pollinating insects like bees and wasps evolved around the same time as angiosperms, a process called coevolution (co-evolution). However, a new study indicates that insect pollination was likely prevalent even before the first flowers. While the oldest fossil bee is about 80 million years old, evidence has been found that bees or wasps built their nests in Arizona's Petrified Forest ( national park Petrified Forest).

These nests, found by Stefan Chasiotis and his team at the University of Colorado, are at least 207 million years old. It is now thought that competition for insect attention likely contributed to the relatively rapid success and diversification of flowering plants. As a variety of flower forms attracted insects for pollination, the insects adapted to different ways collecting nectar and moving pollen, thus creating the complex co-evolutionary systems we are familiar with today.

There is limited evidence that dinosaurs ate angiosperms. According to a study published at the 2015 Annual Meeting of the Society of Paleontologists. Two coprolites (fossilized excrement) of dinosaurs have been found in Utah that contained particles of angiosperms. This conclusion, as well as others (including the presence of angiosperm fruits in the intestines of early Cretaceous ankylosaurs), suggests that some animals fed on flowering plants.

Animal world

During the Cretaceous more began to fly, joining pterosaurs in the air. The origin of flights is debated by many experts. In the tree-down theory, it is thought that small reptiles may have evolved from hopping behavior. The ground-up hypothesis suggests that the small theropods may have jumped high to grab prey and developed the ability to fly. Feathers probably evolved from early integument, the main function of which, most likely, was thermoregulation.

If anything, it is clear that birds were quite successful and became widely diversified during the Cretaceous. Confuciusornis (125-120 million years ago) - a bird with a modern beak and huge claws at the fingertips. Iberomesornis was the size of a sparrow, could run, and probably fed on insects.

By the end of the Jurassic, some large sauropods such as Apatosaurus and Diplodocus became extinct. But other giant sauropods, including titanosaurs, flourished, especially during the late Cretaceous.

Large herds of herbivorous ornithischian dinosaurs also flourished during the Cretaceous, including iguanodonts, ankylosaurs, and horned dinosaurs. Theropods, including Tyrannosaurus rex, continued to remain on top until the end of the Cretaceous.

Mass Cretaceous-Paleogene (K-T) extinction

About 66 million years ago, almost all large and many tropical species died out. Geologists call this event the Cretaceous-Paleogene extinction because it marks the boundary between the Cretaceous and Paleogene periods.

In 1979, a geologist studying rock layers between the Cretaceous and Paleogene discovered a thin layer of gray clay separating the two eras. Other scientists have found this gray layer around the world, and tests have shown that it contains high concentrations of iridium, which is rare on Earth but common in most meteorites.

Also present in this layer are signs of "shocked quartz" and tiny glass particles called tektites, formed as a result of rapid heating and rapid cooling of rock, as occurs when an extraterrestrial object hits the Earth with great force.

The Chicxulub crater on the Yucatan Peninsula dates back to this time. The size of the crater is over 180 kilometers in diameter, and chemical analysis shows that sedimentary rocks areas were melted and mixed together depending on the impact of an asteroid impact with a diameter of about 10 km.

When the asteroid hit the Earth, it caused shock waves, massive tsunamis, and sent a large cloud of hot rocks and dust into the atmosphere. As the hot debris fell to Earth, it triggered numerous Forest fires that raised the ambient temperature.

A rain of dust and rocks raised the planet's global temperature in the hours after the impact and wiped out animals that were too big to seek shelter. Small fauna, hiding under the ground or water, in caves or large tree trunks, probably managed to survive this catastrophe.

Tiny fragments most likely remained in the atmosphere, blocking some of the sun's rays for several months or years. With a reduction in the number sunlight plants could not participate in and died, as did the animals that fed on them.

Smaller, land animals such as mammals, lizards, turtles, and birds may have been able to survive as scavengers by feeding on the carcasses of dead dinosaurs, fungi, roots, and rotting plant matter.

There is also evidence that a series of huge volcanic eruptions occurred along the tectonic boundary between India and Asia, and began just before the Cretaceous-Paleogene extinction event. It is likely that these regional catastrophes have affected many living organisms on the planet.

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Mesozoic era (248-65 million years ago) - the fourth epoch in the evolutionary process of the life of our planet. Its duration is 183 million years. The Mesozoic era is divided into 3 periods: Triassic, Jurassic and Cretaceous.

Periods of the Mesozoic Era

Triassic period (Triassic). The initial erathem of the Mesozoic era lasts 35 million years. This is the time of the formation of the Atlantic Ocean. The single continent of Pangea again begins to break into two parts - Gondwana and Laurasia. Inland continental water bodies begin to dry up actively. The depressions remaining from them are gradually filled with rock deposits. New mountain heights and volcanoes appear, which show increased activity. A huge part of the land is also occupied by desert zones with weather conditions unsuitable for the life of most species of living beings. Salt levels in water bodies are rising. During this time period, representatives of birds, mammals and dinosaurs appear on the planet.

Jurassic period (Jura)- the most famous period of the Mesozoic era. It got its name thanks to the sedimentary deposits of that time found in the Jura (mountains of Europe). The average period of the Mesozoic era lasts about 69 million years. The formation of modern continents begins - Africa, America, Antarctica, Australia. But they are not yet in the order to which we are accustomed. Deep bays and small seas appear, separating the continents. The active formation of mountain ranges continues. The Arctic Sea floods the north of Laurasia. As a result, the climate is humidified, and vegetation forms on the site of deserts.

Cretaceous (Cretaceous). The final period of the Mesozoic era takes a time interval of 79 million years. Angiosperms appear. As a result of this, the evolution of representatives of the fauna begins. The movement of the continents continues - Africa, America, India and Australia are moving away from each other. The continents of Laurasia and Gondwana begin to disintegrate into continental blocks. Huge islands are formed in the south of the planet. The Atlantic Ocean is expanding. The Cretaceous period is the heyday of flora and fauna on land. Due to the evolution of the plant world, fewer minerals enter the seas and oceans. The number of algae and bacteria in water bodies is reduced.

In details periods of the mesozoic era will be considered in the following lectures.

The climate of the Mesozoic era

The climate of the Mesozoic era at the very beginning there was one on the whole planet. The air temperature at the equator and the poles was kept at the same level. At the end of the first period of the Mesozoic era, a drought reigned on Earth for most of the year, which was briefly replaced by rainy seasons. But, despite the arid conditions, the climate became much colder than it was during the Paleozoic period. Some species of reptiles are fully adapted to cold weather. Mammals and birds would later evolve from these animal species.

In the Cretaceous, it gets even colder. All continents have their own climate. Tree-like plants appear, which lose their foliage during the cold season. Snow begins to fall at the North Pole.

Plants of the Mesozoic Era

At the beginning of the Mesozoic, the continents were dominated by club mosses, various ferns, the ancestors of modern palms, conifers and ginkgo trees. In the seas and oceans, the dominance belonged to the algae that formed the reefs.

The increased humidity of the climate of the Jurassic period led to the rapid formation of the plant mass of the planet. The forests consisted of ferns, conifers and cycads. Tui and araucaria grew near water bodies. In the middle of the Mesozoic era, two belts of vegetation formed:

1. Northern, dominated by herbaceous ferns and ginkgo trees;
2. Southern. Tree ferns and cicadas reigned here.

In the modern world, ferns, cycads (palm trees reaching a size of 18 meters) and cordaites of that time can be found in tropical and subtropical forests. Horsetails, club mosses, cypresses and spruce trees practically did not have any differences from those that are common in our time.

The Cretaceous period is characterized by the appearance of plants with flowers. In this regard, butterflies and bees appeared among insects, thanks to which flowering plants could quickly spread across the planet. Also at this time, ginkgo trees begin to grow with foliage falling in the cold season. Coniferous forests of this time period are very similar to modern ones. They include yews, firs and cypresses.

The development of higher gymnosperms lasts throughout the Mesozoic era. These representatives of the terrestrial flora got their name due to the fact that their seeds did not have an outer protective shell. The most widespread are cycads and bennettites. In appearance, cycads resemble tree ferns or cycads. They have straight stems and massive feather-like leaves. Bennettites are trees or shrubs. Outwardly similar to cycads, but their seeds are covered with a shell. This brings plants closer to angiosperms.

In the Cretaceous, angiosperms appear. From this moment begins new stage in development plant life. Angiosperms (flowering) are at the top rung of the evolutionary ladder. They have special reproductive organs - stamens and pistil, which are located in the flower bowl. Their seeds, unlike gymnosperms, hide dense protective shell. These mesozoic era plants quickly adapt to any climatic conditions and are actively developing. In a short time, angiosperms began to dominate the entire Earth. Their various types and forms have reached modern world- eucalyptus, magnolias, quince, oleanders, walnut trees, oaks, birches, willows and beeches. Of the gymnosperms of the Mesozoic era, now we are only familiar with coniferous species - fir, pine, sequoia and some others. The evolution of plant life of that period significantly overtook the development of representatives of the animal world.

Animals of the Mesozoic Era

Animals in the Triassic period of the Mesozoic era actively evolved. A huge variety of more developed creatures was formed, which gradually replaced the ancient species.

One of these types of reptiles was pelycosaurs, similar to animals - sailing lizards. On their backs was a huge sail, similar to a fan. They were replaced by therapsids, which were divided into 2 groups - predators and herbivores. Their paws were powerful, their tails were short. In terms of speed and endurance, therapsids far surpassed pelycosaurs, but this did not save their species from extinction at the end of the Mesozoic era.

The evolutionary group of lizards, from which mammals would later emerge, are the cynodonts (dog teeth). These animals got their name due to powerful jaw bones and sharp teeth, with which they could easily chew raw meat. Their bodies were covered with thick fur. Females laid eggs, but newborn cubs fed on mother's milk.

At the beginning of the Mesozoic era, formed the new kind pangolins - archosaurs (ruling reptiles). They are the ancestors of all dinosaurs, pterosaurs, plesiosaurs, ichthyosaurs, placodonts, and crocodylomorphs. Archosaurs, adapted to the climatic conditions on the coast, became predatory thecodonts. They hunted on land near water bodies. Most thecodonts walked on 4 legs. But there were also individuals who ran on their hind legs. In this way, these animals developed incredible speed. Over time, thecodonts evolved into dinosaurs.

By the end Triassic period dominated by 2 species of reptiles. Some are the ancestors of the crocodiles of our time. Others have become dinosaurs.

Dinosaurs are not like other lizards in body structure. Their paws are located under the body. This feature allowed the dinosaurs to move quickly. Their skin is covered with waterproof scales. Lizards move on 2 or 4 legs, depending on the species. The first representatives were fast coelophyses, powerful herrerasaurs and huge plateosaurs.

In addition to dinosaurs, archosaurs gave rise to another type of reptile that is different from the rest. These are pterosaurs - the first pangolins that can fly. They lived near water bodies, and ate various insects for food.

Animal world sea ​​depths The Mesozoic era is also characterized by a variety of species - ammonites, bivalves, shark families, bony and ray-finned fish. The most outstanding predators were the underwater lizards that appeared not so long ago. Dolphin-like ichthyosaurs had high speed. One of the giant representatives of ichthyosaurs is Shonisaurus. Its length reached 23 meters, and its weight did not exceed 40 tons.

Lizard-like notosaurs had sharp fangs. Plakadonts, similar to modern newts, were searched on seabed shells of mollusks, which were bitten with teeth. Tanystrophei lived on land. Long (2-3 times the size of the body), slender necks allowed them to catch fish standing on the shore.

Another group of marine dinosaurs of the Triassic period are plesiosaurs. At the beginning of the era, plesiosaurs reached a size of only 2 meters, and by the middle of the Mesozoic evolved into giants.

The Jurassic period is the time of the development of dinosaurs. The evolution of plant life gave impetus to the emergence different types herbivorous dinosaurs. And this, in turn, led to an increase in the number of predatory individuals. Some types of dinosaurs were the size of a cat, while others were as large as giant whales. by the most giant specimens are diplodocus and brachiosaurus, reaching a length of 30 meters. Their weight was about 50 tons.

Archeopteryx is the first creature to stand on the border between lizards and birds. Archeopteryx did not yet know how to fly long distances. Their beak was replaced by jaws with sharp teeth. The wings ended in fingers. Archeopteryx were the size of modern crows. They lived mainly in forests, and ate insects and various seeds.

In the middle of the Mesozoic era, pterosaurs are divided into 2 groups - pterodactyls and rhamphorhynchus. Pterodactyls lacked a tail and feathers. But there were large wings and a narrow skull with a few teeth. These creatures lived in flocks on the coast. During the day they hunted for food, and at night they hid in the trees. Pterodactyls ate fish, shellfish and insects. To take to the skies, this group of pterosaurs had to jump from high places. Ramphorhynchus also lived on the coast. They ate fish and insects. They had long tails, which had a blade at the end, narrow wings and a massive skull with teeth of different sizes, with which it was convenient to catch slippery fish.

The most dangerous predator of the deep sea was Liopleurodon, which weighed 25 tons. Huge coral reefs were formed, in which ammonites, belemnites, sponges and sea mats settled. Representatives of the shark family and bone fish develop. New species of plesiosaurs and ichthyosaurs appeared, sea ​​turtles and crocodiles. Saltwater crocodiles have flippers instead of legs. This feature allowed them to increase their speed in the aquatic environment.

During the Cretaceous period of the Mesozoic era there were bees and butterflies. Insects carried pollen, and flowers gave them food. Thus began a long-term cooperation between insects and plants.

The most famous dinosaurs of that time were predatory tyrannosaurs and tarbosaurs, herbivorous bipedal iguanodons, quadrupedal rhinoceros-like Triceratops and small armored ankylosaurs.

Most of the mammals of that period belong to the subclass Allotherium. These are small animals, similar to mice, weighing no more than 0.5 kg. The only exceptional species is repenomamas. They grew up to 1 meter and weighed 14 kg. At the end of the Mesozoic era, the evolution of mammals takes place - the ancestors of modern animals are separated from allotheria. They were divided into 3 types - oviparous, marsupial and placental. It is they who at the beginning of the next era replace the dinosaurs. From the placental species of mammals, rodents and primates appeared. Purgatorius became the first primates. From the marsupial species, modern opossums originated, and the egg-laying species gave rise to platypuses.

AT airspace early pterodactyls and new types of flying reptiles - orcheopteryx and quetzatcoatl reign. These were the most gigantic flying creatures in the entire history of the development of our planet. Together with representatives of pterosaurs, birds dominate the air. In the Cretaceous period, many ancestors of modern birds appeared - ducks, geese, loons. The length of the birds was 4-150 cm, weight - from 20 g. up to several kilograms.

Huge predators reigned in the seas, reaching a length of 20 meters - ichthyosaurs, plesiosaurs and mososaurs. Plesiosaurs had very long necks and small heads. Large sizes did not allow them to develop high speed. The animals ate fish and shellfish. Mososaurs replaced saltwater crocodiles. These are giant predatory lizards with an aggressive character.

At the end of the Mesozoic era, snakes and lizards appeared, the species of which have reached the modern world without changing. Turtles of this time period also did not differ from those that we see now. Their weight reached 2 tons, length - from 20 cm to 4 meters.

By the end of the Cretaceous period, most reptiles begin to die out en masse.

Minerals of the Mesozoic era

A large number of deposits of natural resources are associated with the Mesozoic era. These are sulfur, phosphorites, polymetals, building and combustible materials, oil and natural gas.

On the territory of Asia, in connection with active volcanic processes, the Pacific belt was formed, which gave the world large deposits of gold, lead, zinc, tin, arsenic and other types of rare metals. In terms of coal reserves, the Mesozoic era is significantly inferior to the Paleozoic era, but even during this period several large deposits brown and hard coal - Kansky basin, Bureinsky, Lensky.

Mesozoic oil and gas fields are located in the Urals, Siberia, Yakutia, Sahara. Phosphorite deposits have been found in the Volga and Moscow regions.

Cretaceous - the Cretaceous period - the last period of the Mesozoic era, began 145.5 million years ago and ended 65.5 million years ago. It lasted about 80 million years.

In the Cretaceous period, angiosperms appeared - flowering plants. This entailed an increase in the diversity of insects that became pollinators of flowers. So the vegetation cover of the Earth in the Cretaceous period would no longer surprise modern man. What can not be said about the animal world of that time.

Among the land animals reigned a variety of dinosaurs. Dinosaurs are divided into two groups - lizards, among which were both predators and herbivorous forms, and ornithischians, exclusively herbivores. The most famous lizard dinosaurs are tyrannosaurs, tarbosaurus, brontosaurs. Among ornithischian lizards, ceratopsians, iguanodons, and stegosaurus are known. This was the heyday of giant lizards - many dinosaurs reached 5-8 meters in height and 20 meters in length.

Winged reptiles - pterodactyls occupied almost all niches of aerial predators, although real birds had already appeared. Thus, in parallel there were flying lizards - pterosaurs, gliding, and maybe flying lizards such as Archeopteryx, enanciornis birds and real fan-tailed birds.

The Cretaceous period, which is considered the era of dinosaurs, was also the time of the appearance of most modern groups of mammals. During the Cretaceous, the first placental mammals, and groups of ungulates, insectivores, predators and primates have already stood out.

Modern lizards and snakes evolved, so snakes are a relatively young group. One of the groups of lizards went into the water - this is how mosasaurs arose, formidable predators of the late Cretaceous period, sometimes reaching 20 meters in length. There were no mammals in the seas yet, but a niche large predators occupied by aquatic reptiles - ichthyosaurs, plesiosaurs, pliosaurs. Sharks were large and numerous, some of them also lived in fresh water.

The variety of marine invertebrates was very great. As in the Jurassic, ammonites and belemnites, brachiopods, bivalves and sea ​​urchins. Among bivalve mollusks, rudists, which appeared at the end of the Jura, played an important role in marine ecosystems - mollusks that look like single corals, in which one valve looked like a goblet, and the second covered it like a kind of lid.

By the end of the Cretaceous, a lot of heteromorphic forms appeared among ammonites. Heteromorphs arose earlier, in the Triassic, but the end of the Cretaceous became the time of their mass appearance. The shells of heteromorphs were not similar to the classical spiral-twisted shells of monomorphic ammonites. These could be spirals with a hook at the end, various balls, knots, unfolded spirals. Paleontologists have not yet come to a unified explanation of the causes of the emergence of such forms and their way of life.

Almost modern octopuses and squids already lived in the seas; paleontologists believe that they arose as early as the end of the Jurassic, although they were rarely preserved in the fossil record due to the lack of shells. Whether they contributed to the extinction of their relatives - ammonites and belemnites, or simply occupied the vacated niches after the global crisis - we do not yet know.

During the Cretaceous period, the split of the continents continued. Laurasia and Gondwana fell apart. South America and Africa were moving away from each other, and the Atlantic Ocean was getting wider and wider. Africa, India and Australia also began to move apart, and giant islands eventually formed south of the equator.

At the end of the Cretaceous period, the most famous and very major extinction many groups of plants and animals. Many gymnosperms, all dinosaurs, pterosaurs, aquatic reptiles died out. Ammonites disappeared, many brachiopods, almost all belemnites. In the surviving groups, 30-50% of the species became extinct.

The causes of the Cretaceous catastrophe are not fully understood. Now the asteroid theory has become the most popular theory - explaining the extinction of dinosaurs and other organisms by the fall of a giant asteroid and the “asteroid winter” that followed. Apparently, this is not entirely true. This version cannot explain why certain organisms survived when others died. In addition, many groups of animals clearly began to die out long before the end of the Cretaceous. The transition of the same ammonites to heteromorphic forms also clearly indicates some kind of instability. It may very well be that many species have already been undermined by some long-term processes and stood in the way of extinction, and the catastrophe - an asteroid, increased volcanism or climate change due to the movement of the continents - simply accelerated the process.

On July 14, a trip planned last summer to a new chalk location in the Yuryev-Polsky district took place Vladimir region. The prehistory of its discovery is as follows: a few years ago, during a strong flood in a stream near the village of Pavlovskoye, many brilliant fragments of mother-of-pearl shells were washed up, which in large numbers look like countless treasures, this naturally attracted attention local residents, from which the employee of the Museum of Nature of Vladimir Dudenkov became aware of the finds... >>>

The Cretaceous period is the last epoch that ends the Mesozoic era. He replaced the Jurassic, according to the calculations of geologists, somewhere around 145 million years ago and lasted about eighty million years, after which the Tertiary period began already another, - the "epoch of new life." This rather long stage of the development of the Earth got its name in connection with the fact that it left us powerful deposits of chalk, marl and sand as a legacy. Although during these eighty million years the Earth did not experience any catastrophes on a planetary scale and, consequently, the extinction of a large number of plant and animal species, nevertheless, the movement tectonic plates, change in the level of the world ocean and climate change have made their own amendments to the process of evolution of living beings.

The Cretaceous period is usually divided into subdivisions: lower and upper Cretaceous. In order to understand how life developed in the seas, on land and in the air space of that time, it is necessary to briefly characterize the tectonic mountain-building processes that took place, starting from the Jurassic stage. To the bottom Cretaceous Gondwana and Laurasia continued to move away from each other. Exactly the same process occurred with Africa and South America. Thus, more and more acquired the outlines familiar to us now. But in the east, Gondwana joined with Laurasia. Australia was where it is today, but only a third of the current territory rose above the water.

The Upper Cretaceous is characterized by the fact that the level of the world's oceans began to rise, and huge areas of Eastern Europe, Western Siberia, all of Arabia and almost all of modern Canada were under water. However, by the end of the Cretaceous period, the Earth began to resemble a modern globe with its outlines.

During the Cretaceous period, the climate also changed. He, of course, was much warmer than modern. The spaces of today's Europe were covered with real tropical jungle. However, in high latitudes, the seasons were already changing, and snow fell in winter. This gave impetus to the fact that, along with spore and gymnosperms, closed-sperm plants appeared. Trees such as beech, birch, ash and walnut, which appeared in the Cretaceous era, survived until today without changes. The earth found the first flowering plants - first magnolias, then roses. The flowering plants had the advantage that their pollen was carried not only by the wind, but also by insects. Fruit plants, hiding the seed in the fruit, spread with the help of animals that ate the fruits. Thus, fruit and flowering plants filled the entire planet.

Changes in flora during the Cretaceous period led to the emergence of new species of fauna. The first butterflies began to flutter in the air and bees began to fly, feeding on the nectar of flowers. The dominance of foraminifera sets in in the sea, the dead and crumbled shells of which gave the name to all this geological time. Along with them, other ammonite molluscs appear. The fish kingdom is dominated by sharks and Animals of the Mesozoic era - first of all, dinosaurs and the first mammals - safely "migrated" from the Jurassic to the Cretaceous. But during the Cretaceous, several dead-end branches of bird-like lizards die out, for example, Archeopteryx. But birds appear - the ancestors of modern geese, plovers, ducks and loons.

(Jurassic period in particular), judging by the famous film, is also known as the era of dinosaurs. In general, the supremacy of the ancient lizards is preserved in the Cretaceous. But during the last period, the stegosaurus disappears from the face of the earth, and the tyrannosaurus rex occupies its niche. The rich flora contributed to the emergence of new species of triceratops, iguanodons, ankylosaurs and others. We can say that in the Cretaceous era, the species diversity of dinosaurs reached its peak. And at this time, hiding from the giants in their minks, the future rulers of the Earth lived - mammals. These rat-like animals rarely reached one meter in length, most species were small oviparous, armored or marsupial animals, up to 500 g in weight. But they were the future.