The Mesozoic era is older than the Paleozoic. Mesozoic era. Animals of the Mesozoic era

Kaytsukov A.A. 1

Konstantinova M.V. 1 Boeva E.A. 1

1 Municipal budgetary educational institution secondary school 5, Odintsovo

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INTRODUCTION

The world around us is very rich and diverse. We are surrounded by objects of living and inanimate nature. Nature is a beautiful, mysterious, and sometimes little-studied and unknown world. The history of dinosaurs is very interesting, since it represents a huge era in the life of our planet, in comparison with which human history looks like a moment. But no one can say exactly what color and type these amazing animals were, why some species died out while others appeared, why suddenly at the end of the Cretaceous period these animals completely disappeared from the face of the Earth. You can only speculate and study, study, study. One such little-studied page of living nature includes information about dinosaurs - animals that lived on our planet long before the appearance of humans.

From a very early age I liked watching programs about dinosaurs.

My parents started buying me books, the first thing I did was look for pages that talked about dinosaurs, I looked at drawings with dinosaurs, I was interested in what they looked like, I loved drawing them. When I learned to read, I wanted to understand how they lived, what they looked like, why they became extinct, and whether they had relatives in our world. After all, many modern animals are similar to dinosaurs. I wanted to know more about them.

For example:

How do people learn about the life of dinosaurs?

When did dinosaurs live? How did they appear on our planet?

What did they look like and what did they eat?

Why did dinosaurs become extinct?

I will try to answer all these questions in my research.

Purpose of the study : Analyze known scientific facts about the life of dinosaurs, behavior, reproduction and causes of extinction, find and highlight signs of herbivores and predators. And determine the cause of their death. Having studied the available information about the world of dinosaurs, I will try to justify it. Dinosaurs - who are they?

Tasks:

1. Study the Triassic periods of the Mesozoic era, the features of the animal and plant world of each period.

2. The Jurassic period is the middle period of the Mesozoic era.

3. The Cretaceous period is the last period of the Mesozoic era, which was replaced by the Paleogene period of the Cenozoic era.

Hypothesis: The cause of the death of dinosaurs. The extinction of dinosaurs as a result of sudden climate change on our planet.

Chapter 1. Mesozoic era. Age of dinosaurs.

For many years people thought that the world in which they live was created in the state in which it appears now. And the age of the Earth was considered to be several thousand years. But relatively recently it was proven that the age of our planet exceeds 6 billion years, and, accordingly, life originated a very, very long time ago. It arose through chance, through a unique set of circumstances, and continued to progress. Some forms of life were replaced by new, more perfect ones, which, having existed for thousands and millions of years, disappeared into the abyss of time.

Triassic

The first of three periods of the Mesozoic era. The Triassic period in Earth's history marked the beginning of the Mesozoic era. The Triassic period is a time when the remains of the animal world preserved from the Permian period were replaced by new, revolutionary species of animals. The Triassic period is the time when the first dinosaurs appeared. Although some of the life forms of the Permian period existed throughout the Mesozoic era and went extinct along with the dinosaurs.

Tectonics of the Triassic period:

Back to top Triassic period There was a single continent on Earth - Pangea. During Triassic period, Pangea split into two continents: Laurasia in the northern part and Gondwana in the southern part. A large bay that began in the east of Gondwana extended all the way to the northern coast of modern Africa, then turned south, almost completely separating Africa from Gondwana. A long bay stretched from the west, separating the western part of Gondwana from Laurasia. Many depressions appeared on Gondwana, which were gradually filled with continental sediments. The Atlantic Ocean began to form. The continents were connected to each other. The land prevailed over the sea. The level of salinity in the seas has increased. In the middle of the Triassic period, volcanic activity increased. Inland seas dry up and deep depressions form. Along with changes in the distribution of sea and land, new mountain ranges and volcanic areas were formed. IN Triassic period vast territories were covered with deserts with harsh conditions for animal life. Life bubbled only along the banks of reservoirs.

Triassic became a transition period between the Paleozoic and Mesozoic. There was an intensive replacement of some animal and plant forms by others. Only a few families moved from the Paleozoic era to the Mesozoic. And they existed for many millions of years already in the Triassic. But at this time, new forms of reptiles appeared and developed, which replaced the old ones. At first Triassic period the fauna was the same all over the land. Pangea was a single continent and different species could spread unhindered throughout the land. However, when studying the deposits of the Triassic period, one can easily verify that there is no sharp line between them and the Permian deposits; therefore, some forms of plants and animals were replaced by others, probably gradually. The main reason was not catastrophes, but the evolutionary process: more perfect forms gradually replaced less perfect ones.

The seasonal temperature changes of the Triassic period began to have a noticeable effect on plants and animals. Certain groups of reptiles have adapted to cold seasons. It was from these groups that mammals evolved in the Triassic, and somewhat later, birds. At the end of the Mesozoic era, the climate became even colder. Deciduous woody plants appear, which partially or completely shed their leaves during cold seasons. This feature of plants is an adaptation to a colder climate.

The cooling during the Triassic period was insignificant. It manifested itself most strongly in northern latitudes. The rest of the area was warm. Therefore, reptiles felt quite well in the Triassic period. Their most diverse forms, with which small mammals were not yet able to compete, settled across the entire surface of the Earth. The rich vegetation of the Triassic period also contributed to the extraordinary flourishing of reptiles.

Gigantic forms of cephalopods developed in the seas. The diameter of the shells of some of them was up to 5 m. True, even now the seas are inhabited by gigantic cephalopods, for example squids, reaching 18 m in length, but in the Mesozoic era there were much more gigantic forms. The Triassic seas were inhabited by calcareous sponges, bryozoans, leaf-footed crayfish, and ostracods. Starting from the Triassic period, reptiles, which moved to live in the sea, gradually populated increasingly vast areas of the ocean.

The oldest mammal found in the Triassic sediments of North Carolina is called dromaterium, which means “running beast.” This “beast” was only 12 cm in length. Dromatherium belonged to oviparous mammals. They, like the modern Australian echidna and platypus, did not give birth to young, but laid eggs, from which underdeveloped young hatched. Unlike reptiles, which did not care at all about their offspring, Dromatheriums fed their young with milk.

Deposits of oil, natural gases, brown and hard coal, iron and copper ores, and rock salt are associated with deposits of the Triassic period. The composition of the atmosphere of the Triassic period changed little compared to the Permian. The climate became wetter, but deserts remained in the center of the continent. Some plants and animals of the Triassic period have survived to this day in the region of Central Africa and South Asia. This suggests that the composition of the atmosphere and the climate of individual land areas remained almost unchanged during the Mesozoic and Cenozoic eras.

The Triassic period lasted 35 million years. (Appendix 1-2)

Jurassic period

For the first time, deposits of this period were found in the Jura (mountains in Switzerland and France), hence the name of the period. The Jurassic period is divided into three divisions: Leyas, Doger and Malm.

The deposits of the Jurassic period are quite diverse: limestones, clastic rocks, shales, igneous rocks, clays, sands, conglomerates, formed in a wide variety of conditions.

Sedimentary rocks containing many representatives of fauna and flora are widespread.

Intense tectonic movements at the end of the Triassic and the beginning of the Jurassic periods contributed to the deepening of large bays, which gradually separated Africa and Australia from Gondwanaland. The gulf between Africa and America has deepened. Depressions formed in Laurasia: German, Anglo-Paris, West Siberian. The Arctic Sea flooded the northern coast of Laurasia. The lush vegetation of the Jurassic period contributed to the widespread distribution of reptiles. Dinosaurs have evolved significantly. Among them, lizard-hatched and ornithischian are distinguished. Lizards moved on four legs, had five toes on their feet, and ate plants. At this time, huge, the largest land animals that ever existed on Earth appeared: brachiosaurus, apatosaurus, diplodocus, supersaurus, ultrasaurus and seismosaurus. Small gazelles and larger beaked dinosaurs led a group lifestyle. Then came the amazing spiny dinosaurs. Most of them had a long neck, small head and long tail. They had two brains: one small one in the head; the second is much larger in size - at the base of the tail. The largest of the Jurassic dinosaurs was the Brachiosaurus, reaching a length of 26 m and weighing about 50 tons. It had columnar legs, a small head, and a thick long neck. Brachiosaurs lived on the shores of Jurassic lakes and fed on aquatic vegetation. Every day, the brachiosaurus needed at least half a ton of green mass. Dinosaurs were extremely diverse - some were no larger than a chicken, others reached gigantic sizes . [Ushakov's dictionary, p. 332]. Some hunted and picked up carrion, others nibbled grass and swallowed stones. They all found a mate, laid eggs and raised young. Dinosaurs moved in different ways: some on two legs, some on four legs. Many lizards swam, some even tried to fly. They had to fight, escape from pursuers, hide and die. Fossil remains of dinosaurs have been found in literally all parts of the world. This suggests that dinosaurs lived all over the world. They appeared on our planet about 230 million years ago. But 65 million years ago these wonderful animals became extinct. This time period (more than 160 million years) covers three periods of earth's history (Triassic, Jurassic and Cretaceous), which scientists combine into the Mesozoic era. It is also often called the era of dinosaurs. Although the dinosaurs themselves have long since disappeared from the face of the Earth, the memory of them is reliably preserved by stones. Research has shown that a group of reptiles that lived about 230 million years ago acquired a new way of moving on land. Instead of crawling on widely spaced legs, crouching to the ground like crocodiles, they began to walk on straight legs. Presumably these reptiles were the ancestors of all dinosaurs. The first representatives of dinosaurs arose in the Triassic period. . The first typical representatives of dinosaurs of that time were medium-sized bipedal predators.

Soon, larger and increasingly four-legged herbivorous dinosaurs appeared. Finally, at the end of this period, the first small bipedal herbivores arose. The first birds appeared during the Jurassic period. Their ancestors were the ancient reptiles pseudosuchians, which also gave rise to dinosaurs and crocodiles. Ornithosuchia is most similar to birds. She, like a bird, walked on her hind legs, had a strong pelvis and was covered with feather-like scales. Some pseudosuchians moved to live in trees. Their forelimbs were specialized for grasping branches with their fingers. The pseudosuchian skull had lateral depressions, which significantly reduced the mass of the head. Climbing trees and jumping on branches strengthened the hind limbs. Gradually expanding forelimbs supported the animals in the air and allowed them to glide. An example of such a reptile is Scleromochlusa. His long, thin legs indicate that he was a good jumper. Elongated forearms helped animals climb and cling to branches of trees and bushes. The most important moment in the process of transformation of reptiles into birds was the transformation of scales into feathers. The animals' hearts had four chambers, which ensured a constant body temperature. In the Late Jurassic period, the first birds appeared - Archeopteryx, the size of a pigeon. In addition to short feathers, Archeopteryx had seventeen flight feathers on its wings. The tail feathers were located on all tail vertebrae and were directed back and down. Some researchers believe that the bird's feathers were bright, like those of modern tropical birds, others that the feathers were gray or brown, and still others that they were motley. The mass of the bird reached 200 g. Many signs of Archeopteryx indicate its family ties with reptiles: three free fingers on the wings, a head covered with scales, strong conical teeth, a tail consisting of 20 vertebrae. The bird's vertebrae were biconcave, like those of fish. Archeopteryx lived in araucaria and cycad forests. They ate mainly insects and seeds. Predators appeared among mammals. Small in size, they lived in forests and dense bushes, hunting small lizards and other mammals. Some of them have adapted to life in trees.

Deposits of coal, gypsum, oil, salt, nickel and cobalt are associated with Jurassic deposits.

The Jurassic period lasted 55 million years. (Appendix 3)

1.3.Cretaceous period

The Cretaceous period received this name because thick chalk deposits are associated with it. It is divided into two sections: lower and upper.

Mountain-building processes at the end of the Jurassic period significantly changed the outlines of continents and oceans. North America, previously separated from the vast Asian continent by a wide strait, connected with Europe. In the east, Asia merged with America. South America was completely separated from Africa. Australia was located where it is today, but was smaller in size. The formation of the Andes and Cordilleras, as well as individual ridges of the Far East, continues.

During the Upper Cretaceous period, the sea flooded vast areas of the northern continents. Western Siberia and Eastern Europe, most of Canada and Arabia were under water. Thick layers of chalk, sand, and marls accumulate.

At the end of the Cretaceous period, mountain-building processes were again activated, as a result of which the mountain ranges of Siberia, the Andes, the Cordillera and the mountain ranges of Mongolia were formed.

The climate has changed. In the high latitudes in the north, during the Cretaceous period there was already a real winter with snow. Within the boundaries of the modern temperate zone, some tree species (walnut, ash, beech) were no different from modern ones. The leaves of these trees fell for the winter. However, as before, the climate in general was much warmer than today. Ferns, cycads, ginkgos, bennetites, and conifers, in particular sequoias, yews, pines, cypresses, and spruces, were still common.

In the mid-Cretaceous period, flowering plants flourished. At the same time, they displace representatives of the most ancient flora - spore and gymnosperm plants. It is believed that flowering plants originated and developed in the northern regions, and subsequently they spread throughout the planet. Flowering plants are much younger than conifers, known to us since the Carboniferous period. The dense forests of giant tree ferns and horsetails had no flowers. They adapted well to the living conditions of that time. However, gradually the humid air of the primary forests became increasingly dry. There was very little rain, and the sun was unbearably hot. The soil in the areas of primary swamps dried out. Deserts appeared on the southern continents. Plants moved to areas with cooler, wetter climates in the north. And then the rains came again, saturating the damp soil. The climate of ancient Europe became tropical, and forests similar to modern jungles arose on its territory. The sea recedes again, and plants that inhabited the coast in a humid climate found themselves in a drier climate. Many of them died, but some adapted to new living conditions, forming fruits that protected the seeds from drying out. The descendants of such plants gradually populated the entire planet.

The soil also underwent changes. Silt and the remains of plants and animals enriched it with nutrients.

In primary forests, plant pollen was carried only by wind and water. However, the first plants appeared, the pollen of which insects fed on. Some of the pollen stuck to the wings and legs of the insects, and they transferred it from flower to flower, pollinating the plants. In pollinated plants, the seeds ripened. Plants that were not visited by insects did not reproduce. Therefore, only plants with fragrant flowers of various shapes and colors were distributed.

With the advent of flowers, insects also changed. Among them appear insects that cannot live without flowers at all: butterflies, bees. Fruits with seeds developed from pollinated flowers. Birds and mammals ate these fruits and carried the seeds over long distances, spreading the plants to new areas of the continents. Many herbaceous plants appeared and populated the steppes and meadows. The leaves of the trees fell off in the fall and curled up in the summer heat.

The plants spread to Greenland and the islands of the Arctic Ocean, where it was relatively warm. At the end of the Cretaceous period, with the cooling of the climate, many cold-resistant plants appeared: willow, poplar, birch, oak, viburnum, which are also characteristic of the flora of our time.

With the development of flowering plants, by the end of the Cretaceous period the bennetites became extinct, and the number of cycads, ginkgos, and ferns decreased significantly. Along with the change in vegetation, the fauna also changed.

Foraminifera spread significantly, the shells of which formed thick chalk deposits. The first nummulites appear. Corals formed reefs.

Ammonites of the Cretaceous seas had shells of a peculiar shape. If all the ammonites that existed before the Cretaceous period had shells wrapped in one plane, then the Cretaceous ammonites had elongated shells, bent in the form of a knee, and there were spherical and straight shells. The surface of the shells was covered with spines.

According to some researchers, the bizarre forms of Cretaceous ammonites are a sign of aging of the entire group. Although some representatives of ammonites still continued to reproduce at high speed, their vital energy almost dried up during the Cretaceous period.

According to other scientists, ammonites were exterminated by numerous fish, crustaceans, reptiles, and mammals, and the strange forms of Cretaceous ammonites are not a sign of aging, but mean an attempt to somehow protect themselves from excellent swimmers, which by that time had become bony fish and sharks.

The disappearance of ammonites was also facilitated by a sharp change in physical and geographical conditions in the Cretaceous period.

Belemnites, which appeared much later than ammonites, also completely died out during the Cretaceous period. Among the bivalves there were animals of different shapes and sizes that closed the valves with the help of denticles and pits. In oysters and other mollusks that are attached to the seabed, the valves become different. The lower flap looked like a deep bowl, and the upper one looked like a lid. Among the rudists, the lower valve turned into a large thick-walled glass, inside of which only a small chamber remained for the mollusk itself. The round, lid-like upper flap covered the lower one with strong teeth, with the help of which it could rise and fall. Rudists lived mainly in the southern seas.

In addition to bivalves, whose shells consisted of three layers (outer horny, prismatic and mother-of-pearl), there were mollusks with shells that had only a prismatic layer. These are mollusks of the genus Inoceramus, widely distributed in the seas of the Cretaceous period - animals that reached one meter in diameter.

During the Cretaceous period, many new species of gastropods appeared. Among sea urchins, the number of irregular heart-shaped forms especially increases. And among sea lilies, varieties appear that do not have a stem and float freely in the water with the help of long feathery “arms”.

Great changes have also occurred among fish. In the seas of the Cretaceous period, ganoid fish gradually became extinct. The number of bony fishes is increasing (many of them still exist today). Sharks are gradually acquiring a modern appearance.

Numerous reptiles still lived in the sea. The descendants of the ichthyosaurs that became extinct at the beginning of the Cretaceous period reached 20 m in length and had two pairs of short flippers.

New forms of plesiosaurs and pliosaurs appear. They lived on the open sea. Crocodiles and turtles inhabited freshwater and saltwater basins. The territory of modern Europe was inhabited by large lizards with long spines on their backs and huge pythons.

Of the terrestrial reptiles, trachodons and horned lizards were especially characteristic of the Cretaceous period. Trachodons could move on both two and four legs. They had membranes between their fingers that helped them swim. Trachodons' jaws resembled a duck's beak. They had up to two thousand small teeth.

Triceratops had three horns on their heads and a huge bone shield that reliably protected the animals from predators. They lived mainly in dry places. They ate vegetation. Styracosaurs had nasal projections - horns and six horny spines on the posterior edge of the bony shield. Their heads reached two meters in length. The spines and horns made Styracosaurus dangerous to many predators.

The most terrible predatory lizard was the Tyrannosaurus. It reached a length of 14 m. Its skull, more than a meter long, had large sharp teeth. The tyrannosaurus moved on powerful hind legs, supported by a thick tail. Its front legs were small and weak. The tyrannosaurs left fossilized footprints 80 cm long. The tyrannosaurus's step was 4 m. Flying lizards still continued to exist. The huge pteranodon, whose wingspan was 10 m, had a large skull with a long bony crest on the back of its head and a long toothless beak. The animal's body was relatively small. Pteranodons ate fish. Like modern albatrosses, they spent most of their lives in the air. Their colonies were located by the sea. Recently, the remains of another pteranodon were found in the Cretaceous sediments of America. Its wingspan reached 18 m. Birds appeared that could fly well. Archeopteryx became completely extinct. However, some birds had teeth.

In Hesperornis, a waterfowl, the long finger of the hind limbs was connected to three others by a short swimming membrane. All the fingers had claws. All that remained of the forelimbs were slightly bent humerus bones in the form of a thin stick. Hesperornis had 96 teeth. Young teeth grew inside the old ones and replaced them as soon as they fell out. Hesperornis is very similar to the modern loon. It was very difficult for him to move on land. Raising the front part of the body and pushing off the ground with its feet, Hesperornis moved in small jumps. However, he felt free in the water. He dived well, and it was very difficult for fish to avoid his sharp teeth. In the Late Cretaceous period, toothless birds appeared, whose relatives - flamingos - still exist today. There are many hypotheses regarding the reasons for the extinction of dinosaurs. Some researchers believe that the main reason for this was mammals, of which many appeared at the end of the Cretaceous period. Predatory mammals exterminated dinosaurs, and herbivores intercepted plant food from them. A large group of mammals ate dinosaur eggs. According to other researchers, the main reason for the mass death of dinosaurs was a sharp change in physical and geographical conditions at the end of the Cretaceous period. Cold temperatures and droughts led to a sharp decrease in the number of plants on Earth, as a result of which the giant dinosaurs began to feel a lack of food. They were dying. And the predators for whom dinosaurs served as prey also died, since they had nothing to eat. Perhaps the sun's heat was not enough for the embryos to mature in dinosaur eggs. In addition, cold temperatures also had a detrimental effect on adult dinosaurs. Not having a constant body temperature, they depended on the temperature of the environment. Like modern lizards and snakes, they were active in warm weather, but moved sluggishly in cold weather, could fall into winter torpor and became easy prey for predators. Dinosaurs' skin did not protect them from the cold. And they hardly cared about their offspring. Their parental functions were limited to laying eggs. Unlike dinosaurs, mammals had a constant body temperature, and therefore suffered less from cold snaps. In addition, they were protected by wool. And most importantly, they fed their cubs with milk and took care of them. Thus, mammals had certain advantages over dinosaurs. Birds that had a constant body temperature and were covered with feathers also survived. They incubated eggs and fed chicks.

Among the reptiles that survived were those that took refuge from the cold in burrows and lived in warm areas. From them came modern lizards, snakes, turtles and crocodiles.

The deposits of the Cretaceous period are associated with large deposits of chalk, coal, oil and gas, marls, sandstones, and bauxites.

The Cretaceous period lasted 70 million years. (Appendix 4.)

Chapter 2. Causes of the death of dinosaurs. According to paleontologists, dinosaurs went extinct about 65 million years ago.

Scientists put forward various hypotheses about the reasons for the death of dinosaurs:

Asteroid impact - about 65 million years ago, an asteroid collided with the Earth. this led to the formation of a dust cloud that blocked the Earth from direct sunlight and caused cooling on the planet.

Increased volcanic activity, which led to the release of large amounts of ash into the atmosphere, which covered the Earth from direct sunlight, causing a sharp cooling.

A sharp change in the polarity of the Earth's magnetic field.

An excess amount of oxygen in the atmosphere and water of the Earth, which exceeded its threshold content for dinosaurs, that is, they were simply poisoned by it.

Widespread epidemic among dinosaurs.

The emergence of flowering plants - dinosaurs were unable to adapt to the change in vegetation type.

All these reasons can be divided into two opposing points of view:

The dinosaurs were destroyed by some planetary upheaval.

Dinosaurs simply “didn’t keep up” with the usual but steady change in the Earth’s biosphere.

In modern paleontology, the biosphere version of the extinction of dinosaurs dominates - this is the appearance of flowering plants and gradual climate change. At the same time, insects feeding on flowering plants appeared, and previously existing insects began to die out.

Animals actively adapted to feeding on green mass. Small mammals appeared whose food was only plants. This led to the emergence of corresponding predators, which also became mammals. Small-sized mammalian predators were harmless to adult dinosaurs, but they fed on their eggs and young, creating difficulties for dinosaurs in reproduction.

As a result, unfavorable conditions were created, which led to the cessation of the emergence of new species. The “old” species of dinosaurs existed for some time, but gradually died out completely. At the same time as the dinosaurs, marine reptiles very different from them in their way of life, all flying lizards, many mollusks and other inhabitants of the sea became extinct.

It can also be assumed that dinosaurs did not become extinct at all, but underwent evolutionary development. Thus, American paleontologist John Ostrom came to the sensational conclusion that birds descend directly from small predatory running dinosaurs. He came to this conclusion when he compared the skulls of dinosaurs and modern birds. In his opinion, birds are descendants of not even one, but several branches of dinosaurs.

While excavating, scientists discovered hundreds of different species of dinosaurs. Researchers were able to restore the skeletons of these animals and recreate a picture of their life. Today, in many countries around the world there are museums that display dinosaur specimens. In Russia, the remains of dinosaurs can be seen in the paleontological museum named after Yu.A. Orlova in Moscow. This is one of the largest natural history museums in the world, rich in a collection of dinosaur fossils. In 1815 in England, not far from Oxford, in a quarry where lime was mined, fossilized bones of a giant reptile were discovered. In 1842, the English scientist Richard Owen first used the term “dinosaurs” (terrible lizards) to refer to animals whose three fossilized skeletons were somewhat different from other found skeletons of reptiles.

Conclusion.

From all of the above, we can draw the following conclusions: Dinosaurs lived on earth for a long time (about 160 million years), long before the appearance of humans;

More than a thousand species of dinosaurs existed on Earth during this period;

Dinosaurs became extinct as a result of severe climate change.

When we began research on the topic, I had to sort through a large number of books and magazines dedicated to the Mesozoic era - THE ERA OF DINOSAURS. It turns out that hundreds more questions can be answered on this topic. Therefore, we will continue this work.

Literature:

1M. Avdonina, "Dinosaurs". Complete encyclopedia, M.: Eksmo, 2007.

2.David Burney, translation from English by I.D. Andrianova, Children's encyclopedia “Prehistoric World”;

3.K. Clark, “These Amazing Dinosaurs and Other Prehistoric Animals,” Swallowtail Publishing, 1998.

4. Roger Coote, translation from English by E.V. Komissarova, I want to know everything “Dinosaurs and Planet Earth”;

5.Sheremetyev “Dinosaurs. What? For what? Why?"

6.https://ru.wikipedia.org/wiki/Daming

7.https://yandex.ru/images/search

8. Ushakov’s dictionary, page 332

Annex 1.

Mesozoic era. Age of dinosaurs.

Appendix 2.

Triassic

Appendix 3

Jurassic period

Appendix 4

Cretaceous period

Page 1 of 4

Mesozoic era(248-65 million years ago) - the fourth era in the evolutionary process of life on 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 erathema of the Mesozoic era lasts 35 million years. This is the time of formation of the Atlantic Ocean. The single continent of Pangea again begins to break into two parts - Gondwana and Laurasia. Inland continental reservoirs are beginning to actively dry up. The depressions left from them are gradually filled with rock deposits. New mountain heights and volcanoes are appearing and exhibiting increased activity. A huge part of the land is still occupied by desert zones with weather conditions unsuitable for the life of most species of living beings. The salt level in water bodies is 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 received its name due to the sedimentary deposits of that time found in the Jura (mountain ranges 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 located in the order to which we are accustomed. Deep bays and small seas appear, separating the continents. Active formation of mountain ranges continues. The Arctic Sea floods the north of Laurasia. As a result, the climate is moistened, and vegetation forms in place of deserts.

Cretaceous period (Cretaceous). The final period of the Mesozoic era occupies a time period of 79 million years. Angiosperms appear. As a result of this, the evolution of fauna representatives begins. The movement of continents continues - Africa, America, India and Australia are moving away from each other. The continents of Laurasia and Gondwana begin to break up into continental blocks. Huge islands are forming 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 amount of algae and bacteria in water bodies decreases.

In details periods of the Mesozoic era will be discussed in the following lectures.

Climate of the Mesozoic era

Climate of the Mesozoic era at the very beginning there was one on the entire planet. The air temperature at the equator and poles remained at the same level. At the end of the first period of the Mesozoic era, drought reigned on Earth for most of the year, which was briefly replaced by rainy seasons. But, despite the arid conditions, the climate became significantly colder than it was during the Paleozoic period. Some species of reptiles have fully adapted to cold weather. From these species of animals mammals and birds would later develop.

During the Cretaceous period it becomes 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 lycophytes, various ferns, the ancestors of modern palms, conifers and ginkgo trees. In the seas and oceans, the dominance belonged to algae that formed reefs.

The increased humidity of the climate of the Jurassic period led to the rapid formation of plant matter on the planet. The forests consisted of ferns, conifers and cycads. Thujas and araucarias grew near the ponds. In the middle of the Mesozoic era, two vegetation belts formed:

Northern, which was dominated by herbaceous ferns and gingkovic trees;
Southern. Tree ferns and cycads reigned here.

In the modern world, ferns, cycads (palm trees reaching 18 meters in size) and cordaites of that time can be found in tropical and subtropical forests. Horsetails, mosses, cypresses and spruce trees had practically no 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 were able to quickly spread throughout the planet. Also at this time, ginkgo trees with leaves that fall off during the cold season begin to grow. Coniferous forests of this time period are very similar to modern ones. These include yews, firs and cypresses.

The development of higher gymnosperms lasts throughout the Mesozoic era. These representatives of the earth's 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, cicadas resemble tree ferns or cycads. They have straight stems and massive leaves that look like feathers. Bennettites are trees or shrubs. They are similar in appearance to cycads, but their seeds are covered with a shell. This brings the plants closer to angiosperms.

Angiosperms appeared in the Cretaceous period. From this moment a new stage in the development of plant life begins. Angiosperms (flowering plants) are at the top rung of the evolutionary ladder. They have special reproductive organs - stamens and pistil, which are located in the flower cup. Their seeds, unlike gymnosperms, are hidden by a dense protective shell. These plants of the Mesozoic era quickly adapt to any climatic conditions and actively develop. In a short time, angiosperms began to dominate the entire Earth. Their various types and forms have reached the modern world - eucalyptus, magnolia, quince, oleander, walnut trees, oak, birch, willow and beech. Of the gymnosperms of the Mesozoic era, we are now familiar only with coniferous species - fir, pine, sequoia and some others. The evolution of plant life of that period significantly outstripped 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 formed, which gradually replaced the ancient species.

One of these types of reptiles was the animal-like pelycosaurs - sailing lizards. On their backs there was a huge sail, like a fan. They were replaced by therapsids, which were divided into 2 groups - predators and herbivores. Their legs were powerful and their tails were short. Therapsids were much superior to pelycosaurs in speed and endurance, 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 evolve are the cynodonts (dog teeth). These animals got their name due to their powerful jaw bones and sharp teeth, with which they could easily chew raw meat. Their bodies were covered with thick hair. The females laid eggs, but the newborn cubs fed on their mother's milk.

At the beginning of the Mesozoic era, a new species of lizards emerged - 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 bodies of water. Most thecodonts walked on 4 legs. But there were also individuals that ran on their hind legs. In this way, these animals developed incredible speed. After some time, thecodonts evolved into dinosaurs.

By the end of the Triassic period, 2 species of reptiles predominated. Some are the ancestors of the crocodiles of our time. Others turned into dinosaurs.

Dinosaurs have a body structure that is not similar to other lizards. Their paws are located under the body. This feature allowed 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 coelophysis, powerful herrerasaurs and huge plateosaurs.

Besides dinosaurs, archosaurs gave rise to another species of reptile that was different from the rest. These are pterosaurs - the first lizards that can fly. They lived near bodies of water and ate various insects for food.

The fauna of the deep sea of the Mesozoic era is also characterized by a variety of species - ammonites, bivalves, families of sharks, bony and ray-finned fish. The most prominent 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 nothosaurs had sharp fangs. Placadonts, similar to modern newts, searched for mollusk shells on the seabed, which they bit with their teeth. Tanystrophei lived on land. Long (2-3 times the body size), slender necks allowed them to catch fish while standing on the shore.

Another group of sea lizards 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 they evolved into giants.

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

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

In the middle of the Mesozoic era, pterosaurs were divided into 2 groups - pterodactyls and rhamphorhynchus. Pterodactyls lacked a tail and feathers. But there were large wings and a narrow skull with few teeth. These creatures lived in flocks on the coast. During the day they obtained food for themselves, and at night they hid in the trees. Pterodactyls ate fish, shellfish and insects. This group of pterosaurs had to jump from high places to take to the skies. Rhamphorhynchus also lived on the coast. They ate fish and insects. They had long tails with a blade at the end, narrow wings and a massive skull with teeth of different sizes, which were convenient for catching 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 bony fishes are developing. New species of plesiosaurs and ichthyosaurs, sea turtles and crocodiles appeared. Saltwater crocodiles developed flippers instead of legs. This feature allowed them to increase speed in the aquatic environment.

During the Cretaceous period of the Mesozoic era Bees and butterflies appeared. Insects carried pollen, and flowers gave them food. Thus began a long-term collaboration between insects and plants.

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

Most mammals of that period belong to the subclass Allotheria. These are small animals, similar to mice, weighing no more than 0.5 kg. The only exceptional species is the repenomama. They grew up to 1 meter and weighed 14 kg. At the end of the Mesozoic era, the evolution of mammals occurs - the ancestors of modern animals separate from allotheria. They are divided into 3 species - oviparous, marsupial and placental. It is they who replace the dinosaurs at the beginning of the next era. Rodents and primates emerged from the placental species of mammals. Purgatorius became the first primates. The marsupial species gave rise to modern opossums, and the oviparous species gave rise to platypuses.

The airspace is dominated by early pterodactyls and new species of flying reptiles - Orcheopteryx and Quetzatcoatli. 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. During the Cretaceous period, many ancestors of modern birds appeared - ducks, geese, loons. The length of the birds was 4-150 cm, weight - from 20 grams. up to several kilograms.

The seas were dominated by huge predators reaching 20 meters in length - ichthyosaurs, plesiosaurs and mososaurs. Plesiosaurs had a very long neck and a small head. Their large size 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 unchanged. The turtles of this time period were also no different from those we see now. Their weight reached 2 tons, length - from 20 cm to 4 meters.

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

Minerals of the Mesozoic era

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

In Asia, due to 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 of brown and hard coal were formed - the Kansky basin, Bureinsky, Lensky.

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

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

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general information

The Mesozoic era lasted approximately 160 million years.

years. It is usually divided into three periods: Triassic, Jurassic and Cretaceous; The first two periods were much shorter than the third, which lasted 71 million.

Biologically, the Mesozoic was a time of transition from old, primitive to new, progressive forms. Neither four-rayed corals (rugosas), nor trilobites, nor graptolites crossed the invisible border that lay between the Paleozoic and Mesozoic.

The Mesozoic world was much more diverse than the Paleozoic; the fauna and flora appeared in it in a significantly updated composition.

2. Triassic period

Periodization: from 248 to 213 million years ago.

The Triassic period in Earth's history marked the beginning of the Mesozoic era, or the era of "middle life." Before him, all the continents were merged into a single giant supercontinent, Panagea. With the onset of the Triassic, Pangea again began to split into Gondwana and Laurasia, and the Atlantic Ocean began to form.

Sea levels around the world were very low. The climate, almost everywhere warm, gradually became drier, and vast deserts formed in inland areas. Shallow seas and lakes evaporated intensely, causing the water in them to become very salty.

Animal world.

Dinosaurs and other reptiles became the dominant group of land animals. The first frogs appeared, and a little later land and sea turtles and crocodiles. The first mammals also appeared, and the diversity of mollusks increased.

New species of corals, shrimp and lobsters formed. By the end of the period, almost all ammonites became extinct. Marine reptiles such as ichthyosaurs established themselves in the oceans, and pterosaurs began to colonize the air.

The largest aromorphoses: the appearance of a four-chambered heart, complete separation of arterial and venous blood, warm-bloodedness, mammary glands.

Vegetable world.

Below was a carpet of club mosses and horsetails, as well as palm-shaped bennettites.

Fauna and flora in the Mesozoic. Development of life in the Triassic, Jurassic and Cretaceous periods

Jurassic period

Periodization: from 213 to 144 million years ago.

By the beginning of the Jurassic period, the giant supercontinent Pangea was in the process of active disintegration. There was still a single vast continent south of the equator, which was again called Gondwana. Subsequently, it also split into parts that formed today's Australia, India, Africa and South America.

The sea flooded a significant part of the land. Intensive mountain building took place. At the beginning of the period, the climate was warm and dry everywhere, then it became more humid.

Terrestrial animals of the northern hemisphere could no longer move freely from one continent to another, but they still spread unhindered throughout the southern supercontinent.

Animal world.

The number and diversity of sea turtles and crocodiles increased, and new species of plesiosaurs and ichthyosaurs appeared.

The land was dominated by insects, the predecessors of modern flies, wasps, earwigs, ants and bees. The first bird, Archeopteryx, also appeared. Dinosaurs reigned supreme, evolving into many forms: from giant sauropods to smaller, fleet-footed predators

Vegetable world.

The climate became more humid, and all the land was overgrown with abundant vegetation. The predecessors of today's cypresses, pines and mammoth trees appeared in the forests.

The largest aromorphoses have not been identified.

Cretaceous period

Mesozoic biological Triassic Jurassic

Periodization: from 144 to 65 million years ago.

During the Cretaceous period, the “great split” of continents continued on our planet. The huge land masses that formed Laurasia and Gondwana gradually fell apart. South America and Africa moved away from each other, and the Atlantic Ocean became wider and wider. Africa, India and Australia also began to diverge in different directions, and giant islands eventually formed south of the equator.

Most of the territory of modern Europe was then under water.

The sea flooded vast areas of land.

The remains of hard-covered planktonic organisms formed huge thicknesses of Cretaceous sediments on the ocean floor. At first the climate was warm and humid, but then it became noticeably colder.

Animal world.

The number of belemnites in the seas has increased.

The oceans were dominated by giant sea turtles and predatory marine reptiles. Snakes appeared on land, in addition, new varieties of dinosaurs appeared, as well as insects such as moths and butterflies. At the end of the period, another mass extinction led to the disappearance of ammonites, ichthyosaurs and many other groups of marine animals, and on land all dinosaurs and pterosaurs became extinct.

The largest aromorphosis is the appearance of the uterus and intrauterine development of the fetus.

Vegetable world.

The first flowering plants appeared, establishing close “cooperation” with insects that carried their pollen.

They began to quickly spread throughout the land.

The largest aromorphosis is the formation of a flower and fruit.

5. Results of the Mesozoic era

The Mesozoic era is the era of middle life. It is named so because the flora and fauna of this era are transitional between Paleozoic and Cenozoic. During the Mesozoic era, the modern outlines of continents and oceans, modern marine fauna and flora gradually formed.

The Andes and Cordillera, the mountain ranges of China and East Asia, were formed. The depressions of the Atlantic and Indian oceans were formed. The formation of the Pacific Ocean depressions began. Serious aromorphoses also occurred in the plant and animal worlds. Gymnosperms become the predominant division of plants, and in the animal world the appearance of a four-chambered heart and the formation of the uterus are of equal importance.

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Mesozoic era

The beginning of the Mesozoic era as a transition period in the development of the earth's crust and life.

Significant restructuring of the structural plan of the Earth. Triassic, Jurassic and Cretaceous periods of the Mesozoic era, their description and characteristics (climate, flora and fauna).

presentation, added 05/02/2015

Cretaceous period

Geological structure of the planet during the Cretaceous period. Tectonic changes during the Mesozoic stage of development.

Reasons for the extinction of dinosaurs. The Cretaceous period is the last period of the Mesozoic era. Characteristics of vegetation and animals, their aromorphoses.

presentation, added 11/29/2011

Class Reptiles

Reptiles are a paraphyletic group of predominantly terrestrial vertebrates, including modern turtles, crocodiles, beaked animals, amphisbaenians, lizards, chameleons and snakes.

General characteristics of the largest terrestrial animals, analysis of features.

presentation, added 05/21/2014

Features of studying the fauna of terrestrial vertebrates in urban areas

Urban habitat for animals of any species, species composition of terrestrial vertebrates in the study area.

Classification of animals and features of their biological diversity, environmental problems of synanthropization and synurbanization of animals.

course work, added 03/25/2012

Development of life in the Mesozoic era

Review of the features of the development of the earth's crust and life in the Triassic, Jurassic and Cretaceous periods of the Mesozoic era. Descriptions of the Variscan mountain-building processes, the formation of volcanic areas.

Analysis of climatic conditions, representatives of fauna and flora.

presentation, added 10/09/2012

Development of life on Earth

Geochronological table of the development of life on Earth. Characteristics of climate, tectonic processes, conditions for the emergence and development of life in the Archean, Proterozoic, Paleozoic and Mesozoic eras.

Tracking the process of complication of the organic world.

presentation, added 02/08/2011

History of study, classification of dinosaurs

Characteristics of dinosaurs as a superorder of terrestrial vertebrates that lived in prehistoric times.

Paleontological studies of the remains of these animals. Scientific classification of them into carnivorous and herbivorous subspecies.

History of the study of dinosaurs.

presentation, added 04/25/2016

Herbivorous dinosaurs

A study of the lifestyles of herbivorous dinosaurs, which include all ornithischian dinosaurs and sauropodomorphs, a suborder of saurischians, which shows how diverse they were, even despite the restrictions imposed by their diet.

abstract, added 12/24/2011

Silurian period of the Paleozoic era

The Silurian period is the third geological period of the Paleozoic era.

The gradual sinking of land under water is a characteristic feature of Silurian. Features of the animal world, distribution of invertebrates. The first land plants were psilophytes (naked plants).

presentation, added 10/23/2013

Mesozoic era

Permian mass extinction. The reasons for the extinction of dinosaurs and many other living organisms at the Cretaceous-Paleogene boundary. Beginning, middle and end of the Mesozoic. Fauna of the Mesozoic era.

Dinosaur, pterosaur, rhamphorhynchus, pterodactyl, tyrannosaurus, deinonychus.

presentation, added 05/11/2014

Mesozoic era

The Mesozoic era (252-66 million years ago) is the second era of the fourth eon - Phanerozoic. Its duration is 186 million years. The main features of the Mesozoic: the modern outlines of continents and oceans, modern marine fauna and flora are gradually formed. The Andes and Cordillera, the mountain ranges of China and East Asia, were formed. The depressions of the Atlantic and Indian oceans were formed. The formation of the Pacific Ocean depressions began.

Periods of the Mesozoic era

Triassic period, Triassic, - the first period of the Mesozoic era, lasts 51 million years.

This is the time of formation of the Atlantic Ocean. The single continent of Pangea again begins to break into two parts - Gondwana and Laurasia. Inland continental reservoirs are beginning to actively dry up. The depressions left from them are gradually filled with rock deposits.

New mountain heights and volcanoes are appearing and exhibiting increased activity. A huge part of the land is still occupied by desert zones with weather conditions unsuitable for the life of most species of living beings. The salt level in water bodies is rising. During this time period, representatives of birds, mammals and dinosaurs appear on the planet. Read in detail - Triassic period.

Jurassic period (Jura)- the most famous period of the Mesozoic era.

It received its name due to the sedimentary deposits of that time found in the Jura (mountain ranges of Europe). The average period of the Mesozoic era lasts about 56 million years. The formation of modern continents begins - Africa, America, Antarctica, Australia. But they are not yet located in the order to which we are accustomed.

Deep bays and small seas appear, separating the continents. Active formation of mountain ranges continues. The Arctic Sea floods the north of Laurasia. As a result, the climate is moistened, and vegetation forms in place of deserts.

Cretaceous period (Cretaceous)- the final period of the Mesozoic era, occupies a time period of 79 million years. Angiosperms appear. As a result of this, the evolution of fauna representatives begins. The movement of continents continues - Africa, America, India and Australia are moving away from each other. The continents of Laurasia and Gondwana begin to break up into continental blocks. Huge islands are forming in the south of the planet.

The Atlantic Ocean is expanding. The Cretaceous period is a time of flourishing of flora and fauna on land. Due to the evolution of the plant world, fewer minerals enter the seas and oceans. The amount of algae and bacteria in water bodies decreases. Read in detail - Cretaceous period

Climate of the Mesozoic era

At the very beginning, the climate of the Mesozoic era was uniform throughout the planet. The air temperature at the equator and poles remained at the same level.

At the end of the first period of the Mesozoic era, drought reigned on Earth for most of the year, which was briefly replaced by rainy seasons. But, despite the arid conditions, the climate became significantly colder than it was during the Paleozoic period.

Some species of reptiles have fully adapted to cold weather. From these species of animals mammals and birds would later develop.

Plants of the Mesozoic era

At the beginning of the Mesozoic, the continents were dominated by lycophytes, various ferns, the ancestors of modern palms, conifers and ginkgo trees.

In the seas and oceans, the dominance belonged to algae that formed reefs.

The increased humidity of the climate of the Jurassic period led to the rapid formation of plant matter on the planet. The forests consisted of ferns, conifers and cycads. Thujas and araucarias grew near the ponds. In the middle of the Mesozoic era, two vegetation belts formed:

Northern, which was dominated by herbaceous ferns and gingkovic trees;
Southern.
Tree ferns and cycads reigned here.

In the modern world, ferns, cycads (palm trees reaching 18 meters in size) and cordaites of that time can be found in tropical and subtropical forests.

Horsetails, mosses, cypresses and spruce trees had practically no differences from those that are common in our time.

Also at this time, ginkgo trees with leaves that fall off during the cold season begin to grow. Coniferous forests of this time period are very similar to modern ones.

These include yews, firs and cypresses.

In appearance, cicadas resemble tree ferns or cycads. They have straight stems and massive leaves that look like feathers. Bennettites are trees or shrubs. They are similar in appearance to cycads, but their seeds are covered with a shell. This brings the plants closer to angiosperms.

Angiosperms appeared in the Cretaceous period. From this moment a new stage in the development of plant life begins. Angiosperms (flowering plants) are at the top rung of the evolutionary ladder.

They have special reproductive organs - stamens and pistil, which are located in the flower cup. Their seeds, unlike gymnosperms, are hidden by a dense protective shell. These plants of the Mesozoic era quickly adapt to any climatic conditions and actively develop. In a short time, angiosperms began to dominate the entire Earth. Their various types and forms have reached the modern world - eucalyptus, magnolia, quince, oleander, walnut trees, oaks, birches, willows and beeches.

Of the gymnosperms of the Mesozoic era, we are now familiar only with coniferous species - fir, pine, sequoia and some others. The evolution of plant life of that period significantly outstripped the development of representatives of the animal world.

Animals of the Mesozoic era

Animals actively evolved during the Triassic period of the Mesozoic era.

A huge variety of more developed creatures formed, which gradually replaced the ancient species.

One of these types of reptiles was the animal-like pelycosaurs - sailing lizards.

On their backs there was a huge sail, like a fan. They were replaced by therapsids, which were divided into 2 groups - predators and herbivores.

Their legs were powerful and their tails were short. Therapsids were much superior to pelycosaurs in speed and endurance, but this did not save their species from extinction at the end of the Mesozoic era.

Their bodies were covered with thick hair. The females laid eggs, but the newborn cubs fed on their mother's milk.

At the beginning of the Mesozoic era, a new species of lizards emerged - 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 bodies of water. Most thecodonts walked on four legs. But there were also individuals that ran on their hind legs. In this way, these animals developed incredible speed. After some time, thecodonts evolved into dinosaurs.

By the end of the Triassic period, two species of reptiles predominated. Some are the ancestors of the crocodiles of our time.

Others turned into dinosaurs.

Dinosaurs have a body structure that is not similar to other lizards. Their paws are located under the body.

This feature allowed 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 coelophysis, powerful herrerasaurs and huge plateosaurs.

Besides dinosaurs, archosaurs gave rise to another species of reptile that was different from the rest.

These are pterosaurs - the first lizards that can fly. They lived near bodies of water and ate various insects for food.

One of the giant representatives of ichthyosaurs is Shonisaurus. Its length reached 23 meters, and its weight did not exceed 40 tons.

Lizard-like nothosaurs had sharp fangs.

Placadonts, similar to modern newts, searched for mollusk shells on the seabed, which they bit with their teeth. Tanystrophei lived on land. Long (2-3 times the body size), slender necks allowed them to catch fish while standing on the shore.

The Jurassic period is the time of the development of dinosaurs.

The evolution of plant life gave rise to the emergence of different types of herbivorous dinosaurs. And this, in turn, led to an increase in the number of predatory individuals. Some dinosaur species were the size of cats, while others were as large as giant whales. The most gigantic individuals are diplodocus and brachiosaurs, reaching a length of 30 meters.

Their weight was about 50 tons.

They lived mainly in forests and ate insects and various seeds.

In the middle of the Mesozoic era, pterosaurs were divided into 2 groups - pterodactyls and rhamphorhynchus.

Pterodactyls lacked a tail and feathers. But there were large wings and a narrow skull with few teeth. These creatures lived in flocks on the coast. During the day they obtained food for themselves, and at night they hid in the trees. Pterodactyls ate fish, shellfish and insects. This group of pterosaurs had to jump from high places to take to the skies. Rhamphorhynchus also lived on the coast. They ate fish and insects. They had long tails with a blade at the end, narrow wings and a massive skull with teeth of different sizes, which were convenient for catching 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 bony fishes are developing. New species of plesiosaurs and ichthyosaurs, sea turtles and crocodiles appeared. Saltwater crocodiles developed flippers instead of legs. This feature allowed them to increase speed in the aquatic environment.

During the Cretaceous period of the Mesozoic era, bees and butterflies appeared. Insects carried pollen, and flowers gave them food.

Thus began a long-term collaboration between insects and plants.

Most mammals of that period belong to the subclass Allotheria.

These are small animals, similar to mice, weighing no more than 0.5 kg. The only exceptional species is the repenomama. They grew up to 1 meter and weighed 14 kg. At the end of the Mesozoic era, the evolution of mammals occurs - the ancestors of modern animals separate from allotheria. They are divided into 3 species - oviparous, marsupial and placental. It is they who replace the dinosaurs at the beginning of the next era. Rodents and primates emerged from the placental species of mammals. Purgatorius became the first primates.

The marsupial species gave rise to modern opossums, and the oviparous species gave rise to platypuses.

Together with representatives of pterosaurs, birds dominate the air. During the Cretaceous period, many ancestors of modern birds appeared - ducks, geese, loons. The length of the birds was 4-150 cm, weight - from 20 grams. up to several kilograms.

The seas were dominated by huge predators reaching 20 meters in length - ichthyosaurs, plesiosaurs and mososaurs. Plesiosaurs had a very long neck and a small head.

Their large size 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.

Their weight reached 2 tons, length - from 20 cm to 4 meters.

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

Minerals of the Mesozoic era

A large number of natural resource deposits are associated with the Mesozoic era.

These are sulfur, phosphorites, polymetals, construction and combustible materials, oil and natural gas.

Mesozoic oil and gas fields are located in the Urals, Siberia, Yakutia, and the Sahara.

Phosphorite deposits have been found in the Volga region and Moscow region.

To the table: Phanerozoic eon

01 of 04. Periods of the Mesozoic era

The Paleozoic era, like all major eras on a geological time scale, ended with a mass extinction. The Permian mass extinction is considered the largest loss of species in Earth's history. Almost 96% of all living species were wiped out due to the large number of volcanic eruptions that led to massive and relatively rapid climate change during the Mesozoic era.

The Mesozoic Era is often called the "Age of the Dinosaurs" because it is the time period in which dinosaurs evolved and eventually went extinct.

The Mesozoic era is divided into three periods: Triassic, Jurassic and Cretaceous.

02 of 04. Triassic period (251 million years ago - 200 million years ago)

Fossil of Pseudopalatus from the Triassic period.

National Park Service

The beginning of the Triassic period was quite sparse in terms of life forms on Earth. Because there were so few species left after the Permian mass extinction, it took a very long time for recolonization and increased biodiversity. The Earth's topography also changed during this time period. At the beginning of the Mesozoic era, all continents were connected into one large continent. This supercontinent was named Pangea.

During the Triassic period, continents began to separate due to plate tectonics and continental drift.

As animals began to emerge from the oceans again and colonize nearly empty land, they also learned to dig burrows to protect themselves from environmental changes. For the first time in history, amphibians such as frogs appeared, followed by reptiles such as turtles, crocodiles, and eventually dinosaurs.

By the end of the Triassic period, birds also appeared, splitting off from the dinosaur branch of the phylogenetic tree.

Plants were also few in number. In the Triassic period they began to flourish again.

Development of life in the Mesozoic era

Most land plants at that time were conifers or ferns. By the end of the Triassic period, some of the ferns had developed seeds for reproduction. Unfortunately, another mass extinction brought an end to the Triassic period. This time, about 65% of the species on Earth did not survive.

03 of 04. Jurassic period (200 million years ago - 145 million years ago)

Plesiosaur from the Jurassic period.

Tim Evanson

After the Triassic mass extinction, life and species diversified to fill niches that were left open. Pangea broke into two large parts - Laurasia was a land mass in the north, and Gondwana was in the south. Between these two new continents was the Tethys Sea. Diverse climates on each continent allowed many new species to emerge for the first time, including lizards and small mammals. However, dinosaurs and flying reptiles continued to dominate the land and sky.

There were a lot of fish in the oceans.

Plants bloomed on earth for the first time. There were numerous extensive pastures for herbivores, which also provided food for predators. The Jurassic period was like a Renaissance era for life on Earth.

04 of 04. Cretaceous period (145 million years ago - 65 million years ago)

Fossil Pachycephalosaurus from the Cretaceous period.

Tim Evanson

The Cretaceous period is the last period of the Mesozoic era. Favorable conditions for life on Earth continued from the Jurassic period to the early Cretaceous period. Laurasia and Gondwana began to expand even further, eventually forming the seven continents we see today. As landmass expanded, Earth's climate became warm and humid. These were very favorable conditions for plant life to flourish. Flowering plants began to proliferate and dominate the land.

As plant life was abundant, the population of herbivores also increased, which in turn led to an increase in the number and size of predators. Mammals also began to split into many species, just as dinosaurs did.

Life in the ocean developed according to a similar scenario. The warm and humid climate maintained high sea levels. This has contributed to an increase in the biodiversity of marine species.

All tropical areas of the Earth were covered with water, so the climatic conditions were largely ideal for the diversity of life.

As before, these almost ideal conditions would have to end sooner or later. This time, the mass extinction that ended the Cretaceous period and then the entire Mesozoic era is thought to have been caused by one or more large meteors hitting the Earth. The ash and dust released into the atmosphere blocked the sun, slowly killing off all the lush plant life that had accumulated on the land.

Likewise, most of the species in the ocean also disappeared during this time. As there were fewer and fewer plants, herbivores also gradually died out. Everything went extinct: from insects to large birds and mammals and, of course, dinosaurs. Only small animals that were able to adapt and survive in conditions of little food were able to see the beginning of the Cenozoic era.

Sources

Mesozoic deposits- sediments, sediments formed during the Mesozoic era. Mesozoic deposits include the Triassic, Jurassic and Cretaceous systems (periods).

In Mordovia, only Jurassic and Cretaceous sedimentary rocks are present. In the Triassic period (248 - 213 million years), the territory of Mordovia was dry land and sediments were not deposited. During the Jurassic period (213 - 144 million years), throughout the entire territory of the republic there was a sea in which clays, sands, and, less commonly, phosphorite nodules and carbonaceous shales accumulated.

Jurassic deposits reach the surface on 20 - 25% of the area (mainly along river valleys), with a thickness of 80 - 140 m. Associated with them are deposits of minerals - oil shale and phosphorites. During the Cretaceous period (144 - 65 million years) the sea continued to exist, and sediments of this age come to the surface on 60 - 65% of the territory in all regions of the Republic of Mordovia.

They are represented by 2 groups - Lower and Upper Cretaceous. On the eroded surface of Jurassic deposits (oil shale and dark clays) lie Lower Cretaceous: phosphorite conglomerate, greenish-gray and black clays and sands with a total thickness of up to 110 m. Upper Cretaceous deposits consist of light gray and white chalk, marl, opoka and make up the Cretaceous mountains in the southeastern regions of the Republic of Mordovia.

Thin layers are marked by green glauconitic and phosphorite-bearing sands. In other layers there are nodules and nodules of phosphorites, fossilized remains of organisms (belemnites, popularly called “devil’s fingers”). The total thickness is approximately 80 m.

Mesozoic era

The Atemarskoye and Kulyasovskoye chalk deposits and the Alekseevskoye deposit of cement raw materials are confined to the Upper Cretaceous deposits.

[edit] Source

A. A. Mukhin. Alekseevsky cement plant quarry. 1965

Mesozoic era

The Mesozoic era began approximately 250 and ended 65 million years ago. It lasted 185 million years. The Mesozoic era is divided into the Triassic, Jurassic and Cretaceous periods with a total duration of 173 million years. The deposits of these periods constitute the corresponding systems, which together form the Mesozoic group.

The Mesozoic is known primarily as the era of dinosaurs. These giant reptiles overshadow all other groups of living beings.

But you shouldn’t forget about others. After all, it was the Mesozoic - the time when real mammals, birds, and flowering plants appeared - that actually formed the modern biosphere.

And if in the first period of the Mesozoic - the Triassic, there were still many animals on Earth from Paleozoic groups that were able to survive the Permian catastrophe, then in the last period - the Cretaceous, almost all those families that flourished in the Cenozoic era had already formed.

The Mesozoic era was a transitional period in the development of the earth's crust and life. It can be called the geological and biological Middle Ages.
The beginning of the Mesozoic era coincided with the end of the Variscan mountain-building processes; it ended with the beginning of the last powerful tectonic revolution - the Alpine folding.

In the Southern Hemisphere, the Mesozoic saw the end of the collapse of the ancient continent of Gondwana, but overall the Mesozoic era here was an era of relative calm, only occasionally and briefly disrupted by slight folding.

The early stage of development of the plant kingdom - paleophyte, was characterized by the dominance of algae, psilophytes and seed ferns. The rapid development of more highly developed gymnosperms, which characterizes the “plant Middle Ages” (mesophyte), began in the Late Permian era and ended at the beginning of the Late Cretaceous era, when the first angiosperms, or flowering plants (Angiospermae), began to spread.

The Cenophyte, the modern period of development of the plant kingdom, began in the Late Cretaceous.

This made their resettlement quite difficult. The development of seeds allowed plants to lose such close dependence on water. The ovules could now be fertilized by pollen carried by the wind or insects, and water thus no longer determined reproduction. In addition, unlike a single-celled spore with its relatively small supply of nutrients, the seed has a multicellular structure and is able to provide food for a young plant in the early stages of development for longer.

Under unfavorable conditions, the seed can remain viable for a long time. Having a durable shell, it reliably protects the embryo from external dangers. All these advantages gave seed plants good chances in the struggle for existence. The ovule (ovum) of the first seed plants was unprotected and developed on special leaves; the seed that emerged from it also did not have an outer shell.

Among the most numerous and most curious gymnosperms of the beginning of the Mesozoic era we find the Cycas, or sago. Their stems were straight and columnar, similar to tree trunks, or short and tuberous; they bore large, long and usually feathery leaves
(for example, the genus Pterophyllum, whose name means “feathery leaves”).

Outwardly, they looked like tree ferns or palm trees.
In addition to the cycads, the Bennettitales, represented by trees or shrubs, became of great importance in the mesophyte. They mostly resemble true cycads, but their seed begins to develop a tough shell, which gives Bennettites an angiosperm-like appearance.

There are other signs of adaptation of Bennettites to conditions of a drier climate.

In the Triassic, new forms came to the fore.

Conifers are spreading quickly, and among them are firs, cypresses, and yews. Among the ginkgos, the genus Baiera has become widespread. The leaves of these plants had the shape of a fan-shaped plate, deeply dissected into narrow lobes. Ferns have taken over damp, shady places along the banks of small bodies of water (Hausmannia and other Dipteraidae). Forms that grow on rocks (Gleicheniacae) are also known among ferns. Horsetails (Equisetites, Phyllotheca, Schizoneura) grew in the swamps, but did not reach the size of their Paleozoic ancestors.
In the middle mesophyte (Jurassic period), the mesophytic flora reached the culmination point of its development.

The hot tropical climate in what is now the temperate zone was ideal for tree ferns to thrive, while smaller fern species and herbaceous plants preferred the temperate zone. Among the plants of this time, gymnosperms continue to play a dominant role
(primarily cycads).

The Cretaceous period is marked by rare changes in vegetation.

The flora of the Lower Cretaceous still resembles in composition the vegetation of the Jurassic period. Gymnosperms are still widespread, but their dominance ends at the end of this time.

Even in the Lower Cretaceous, the most progressive plants suddenly appeared - angiosperms, the predominance of which characterizes the era of new plant life, or Cenophyte.

Angiosperms, or flowering plants (Angiospermae), occupy the highest level of the evolutionary ladder of the plant world.

Their seeds are enclosed in a durable shell; there are specialized reproductive organs (stamen and pistil) assembled into a flower with bright petals and a calyx. Flowering plants appear somewhere in the first half of the Cretaceous period, most likely in a cold and dry mountain climate with large temperature differences.
With the gradual cooling that marked the Cretaceous, they captured more and more new areas on the plains.

Quickly adapting to their new environment, they evolved at amazing speed. Fossils of the first true angiosperms are found in the Lower Cretaceous rocks of Western Greenland, and a little later also in Europe and Asia. In a relatively short time, they spread throughout the Earth and reached great diversity.

From the end of the Early Cretaceous era, the balance of forces began to change in favor of angiosperms, and by the beginning of the Upper Cretaceous their superiority became widespread. Cretaceous angiosperms belonged to the evergreen, tropical or subtropical types, among them were eucalyptus, magnolia, sassafras, tulip trees, Japanese quince trees, brown laurels, walnut trees, plane trees, and oleanders. These heat-loving trees coexisted with the typical flora of the temperate zone: oaks, beeches, willows, and birches.

For gymnosperms, this was a time of surrender. Some species have survived to this day, but their total numbers have been declining all these centuries. A definite exception is conifers, which are still found in abundance today.
In the Mesozoic, plants made a great leap forward, surpassing animals in terms of development rates.

Mesozoic invertebrates were already approaching modern ones in character.

A prominent place among them was occupied by cephalopods, to which modern squids and octopuses belong. The Mesozoic representatives of this group included ammonites with a shell twisted into a “ram’s horn”, and belemnites, the inner shell of which was cigar-shaped and overgrown with the flesh of the body - the mantle.

Belemnite shells are popularly known as “devil’s fingers.” Ammonites were found in such numbers in the Mesozoic that their shells are found in almost all marine sediments of this time.

Ammonites appeared in the Silurian, they experienced their first flowering in the Devonian, but reached their highest diversity in the Mesozoic. In the Triassic alone, over 400 new genera of ammonites arose.

Particularly characteristic of the Triassic were ceratids, which were widespread in the Upper Triassic marine basin of Central Europe, the deposits of which in Germany are known as shell limestone.

By the end of the Triassic, most ancient groups of ammonites died out, but representatives of the Phylloceratida survived in Tethys, the giant Mesozoic Mediterranean Sea. This group developed so rapidly in the Jurassic that the ammonites of this time surpassed the Triassic in the variety of forms.

During the Cretaceous, cephalopods, both ammonites and belemnites, remained numerous, but during the Late Cretaceous the number of species in both groups began to decline. Among the ammonites at this time, aberrant forms with an incompletely twisted hook-shaped shell (Scaphites), with a shell elongated in a straight line (Baculites) and with an irregularly shaped shell (Heteroceras) appeared.

These aberrant forms appeared, apparently, as a result of changes in the course of individual development and narrow specialization. The terminal Upper Cretaceous forms of some branches of ammonites are distinguished by sharply increased shell sizes. In the genus Parapachydiscus, for example, the shell diameter reaches 2.5 m.

The mentioned belemnites also acquired great importance in the Mesozoic.

Some of their genera, for example, Actinocamax and Belenmitella, are important fossils and are successfully used for stratigraphic division and accurate determination of the age of marine sediments.
At the end of the Mesozoic, all ammonites and belemnites became extinct.

Of the cephalopods with an external shell, only the genus Nautilus has survived to this day. More widespread in modern seas are forms with internal shells - octopuses, cuttlefish and squids, distantly related to belemnites.
The Mesozoic era was a time of unstoppable expansion of vertebrates. Of the Paleozoic fishes, only a few transitioned into the Mesozoic, as did the genus Xenacanthus, the last representative of the freshwater sharks of the Paleozoic, known from freshwater sediments of the Australian Triassic.

Sea sharks continued to evolve throughout the Mesozoic; Most modern genera were already represented in the Cretaceous seas, in particular, Carcharias, Carcharodon, lsurus, etc.

Ray-finned fish, which arose at the end of the Silurian, initially lived only in freshwater reservoirs, but with the Permian they began to enter the seas, where they multiplied unusually and from the Triassic to the present day they retained a dominant position.
Reptiles became most widespread in the Mesozoic, becoming truly the dominant class of this era.

In the course of evolution, a variety of genera and species of reptiles appeared, often of very impressive size. Among them were the largest and most bizarre land animals the earth has ever bore.

As already mentioned, in terms of anatomical structure, the most ancient reptiles were close to labyrinthodonts. The oldest and most primitive reptiles were the clumsy cotylosaurs (Cotylosauria), which appeared already at the beginning of the Middle Carboniferous and became extinct by the end of the Triassic. Among cotylosaurs, both small animal-eating and relatively large herbivorous forms (pareiasaurs) are known.

The descendants of cotylosaurs gave rise to the entire diversity of the reptile world. One of the most interesting groups of reptiles that developed from cotylosaurs were the beast-like animals (Synapsida, or Theromorpha), their primitive representatives (pelycosaurs) have been known since the end of the Middle Carboniferous. In the middle of the Permian period, pelycosaurs, known mainly from North America, die out, but in the Old World they are replaced by more progressive forms that form the order Therapsida.
The predatory theriodonts (Theriodontia) included in it are already very similar to primitive mammals, and it is no coincidence - it was from them that the first mammals developed by the end of the Triassic.

During the Triassic period, many new groups of reptiles appeared.

These include turtles, ichthyosaurs ("fish lizards"), well adapted to marine life, resembling dolphins in appearance, and placodonts, clumsy armored animals with powerful flattened teeth adapted for crushing shells, and also plesiosaurs that lived in the seas, having a relatively small head, more or a less elongated neck, a wide body, flipper-like paired limbs and a short tail; Plesiosaurs vaguely resemble giant shellless turtles.

In the Jurassic, plesiosaurs, like ichthyosaurs, reached their peak. Both of these groups remained very numerous into the Early Cretaceous, being extremely characteristic predators of the Mesozoic seas.
From an evolutionary point of view, one of the most important groups of Mesozoic reptiles were thecodonts, small predatory reptiles of the Triassic period, which gave rise to the most diverse groups - crocodiles, dinosaurs, flying lizards, and, finally, birds.

However, the most remarkable group of Mesozoic reptiles were the well-known dinosaurs.

They developed from thecodonts back in the Triassic and took a dominant position on Earth in the Jurassic and Cretaceous. Dinosaurs are represented by two groups, completely separate - saurischia (Saurischia) and ornithischia (Ornithischia). In the Jurassic, real monsters could be found among dinosaurs, up to 25-30 m long (including tail) and weighing up to 50 tons. Of these giants, the best known forms are Brontosaurus, Diplodocus and Brachiosaurus.

And in the Cretaceous period the evolutionary progress of dinosaurs continued. Among the European dinosaurs of this time, bipedal iguanodonts are widely known; in America, four-legged horned dinosaurs (Triceratops) Styracosaurus, etc.), somewhat reminiscent of modern rhinoceroses, became widespread.

Also interesting are the relatively small armored dinosaurs (Ankylosauria), covered with a massive bony shell. All named forms were herbivores, as well as giant duck-billed dinosaurs (Anatosaurus, Trachodon, etc.), which walked on two legs.

In the Cretaceous, predatory dinosaurs also flourished, the most remarkable of which were such forms as Tyrannosaurus rex, whose length exceeded 15 m, Gorgosaurus and Tarbosaurus.

All of these forms, which turned out to be the greatest land predatory animals in the entire history of the Earth, walked on two legs.

At the end of the Triassic, the thecodonts also gave rise to the first crocodiles, which became abundant only in the Jurassic period (Steneosaurus and others). In the Jurassic period, flying lizards appeared - pterosaurs (Pterosauria), also descended from thecodonts.
Among the flying dinosaurs of the Jurassic, the most famous are Rhamphorhynchus and Pterodactylus; among the Cretaceous forms, the most interesting is the relatively very large Pteranodon.

Flying lizards became extinct by the end of the Cretaceous.
In the Cretaceous seas, giant predatory mosasaurian lizards, exceeding 10 m in length, became widespread. Among modern lizards, they are closest to monitor lizards, but differ from them, in particular, in their flipper-like limbs.

By the end of the Cretaceous, the first snakes (Ophidia) appeared, apparently descended from lizards that led a burrowing lifestyle.
Towards the end of the Cretaceous, there was a mass extinction of characteristic Mesozoic groups of reptiles, including dinosaurs, ichthyosaurs, plesiosaurs, pterosaurs and mosasaurs.

Representatives of the class of birds (Aves) first appear in Jurassic deposits.

Brief information about the Mesozoic era

The remains of Archaeopteryx, the well-known and so far only known first bird, were found in lithographic shales of the Upper Jurassic, near the Bavarian city of Solnhofen (Germany). During the Cretaceous period, the evolution of birds proceeded at a rapid pace; The characteristic genera of this time were Ichthyornis and Hesperornis, which still had serrated jaws.

The first mammals (Mattalia), modest animals no larger than a mouse, descended from animal-like reptiles in the Late Triassic.

Throughout the Mesozoic they remained few in number and by the end of the era the original genera were largely extinct.

The most ancient group of mammals were the triconodonts (Triconodonta), to which the most famous of the Triassic mammals, Morganucodon, belongs. Appears in the Jurassic
a number of new groups of mammals - Symmetrodonta, Docodonta, Multituberculata and Eupantotheria.

Of all the named groups, only the Multituberculata survived the Mesozoic, the last representative of which died out in the Eocene. Polytuberculates were the most specialized of the Mesozoic mammals, convergently they had some similarities with rodents.

The ancestors of the main groups of modern mammals - marsupials (Marsupialia) and placentals (Placentalia) were Eupantotheria. Both marsupials and placentals appeared in the Late Cretaceous. The most ancient group of placentals are insectivores (insectivora), which have survived to this day.

The Mesozoic era is a period in the geological history of the Earth from 251 million to 65 million years ago. It is at this stage of the Earth’s history that the formation of the main contours of modern continents and mountain building occurs. on the periphery of the Pacific, Atlantic and Indian oceans. Favorable climatic conditions and the division of land contributed to important evolutionary events in the life of the biosphere - by the end of the Mesozoic, the main part of the species diversity of life on Earth approached its modern state. Today we can judge the natural and climatic conditions, tectonic processes, atmospheric composition, animal and plant kingdoms of the Mesozoic era from a variety of geological evidence. As you know, the closer the events take place to the modern period of history, the more interesting and extensive information about the past can be gleaned from the geological record of the Earth.
If for previous eras the main data were obtained through the study of rock sediments of modern continents, then already for the second half of the Mesozoic and beyond, scientists have important evidence for the seas and oceans. The Paleozoic era ended with the Hercynian stage of folding. The folded systems formed in the Paleozoic on the site of the North Atlantic, Ural-Tien Shan and Mongol-Okhotsk geosynclines contributed to the connection of the northern platforms into a huge single massif - Laurasia. This continent stretches from the Rocky Mountains of North America to the Verkhoyansk Range in northeast Asia.

The Southern Hemisphere had its own huge platform - the continent of Gondwana, which united South America, Antarctica, Africa, Hindustan and Australia. At a certain period of the Earth's history, Laurasia and Gondwana were one whole - the supercontinent Pangea. But it was in the Mesozoic era that the gradual disintegration of Pangea and the process of formation of modern continents and oceans began. Therefore, the Mesozoic is often called a transitional period in the development of the earth's crust, a real geological Middle Ages.

This era is best remembered as the era of the dinosaurs. It lasted about half as long as the Paleozoic era, but was rich in events. This was a time when plants, fish, shellfish, and especially reptiles, reached enormous sizes, as if everything on Earth was then on megavitamins. Dinosaurs buried themselves in giant ferns and enormous trees, while pterosaurs (flying reptiles) cruised the skies. Climatic conditions were warm everywhere.

While geologists can only speculate about the forces that led to the breakup of the supercontinent Pangea into Laurasia and Gondian at this time, the example of Antarctica suggests magmatic hotspots causing faults across the globe. In some areas, dinosaurs and plants became isolated for millions of years and developed special characteristics depending on their habitats, as well as local food and temperature conditions. Even small mammals began to fall under the feet of carnivorous dinosaurs, such as Tyrannosaurus Rex, as an occasional snack.

During the Mesozoic era, more modern forms of insects, corals, marine organisms, and flowering plants began to evolve. Everything was really wonderful, when suddenly dinosaurs and many other animals became extinct. Many scientists believe that this was caused by a collision with a large asteroid and the resulting atmospheric smoke, volcanic eruptions and generally inclement weather observed in the following years. The sun couldn't break through the ash and smoke, the water was polluted, and Earth wasn't exactly a big resort.

The Mesozoic consists of three periods: Triassic, Jurassic, Cretaceous.

In the Triassic Most of the land was above sea level, the climate was dry and warm. Due to the very dry climate in the Triassic, almost all amphibians disappeared. Therefore, the flourishing of reptiles began, which were adapted to drought (Fig. 44). Among plants in the Triassic, strong development was achieved gymnosperms.

Rice. 44. Various types of reptiles of the Mesozoic era

Of the Triassic reptiles, turtles and hatteria have survived to this day.

Preserved on the islands of New Zealand, the hatteria is a true “living fossil.” Over the past 200 million years, hatteria has remained almost unchanged and, like its Triassic ancestors, has retained the third eye located in the roof of the skull.

Among reptiles, the rudiment of the third eye is preserved in lizards agamas and batbats.

Along with the undoubted progressive features in the organization of reptiles, there was one very significant imperfect feature - inconsistent body temperature. In the Triassic period, the first representatives of warm-blooded animals appeared - small primitive mammals - tricodonts. They originated from ancient beast-toothed lizards. But rat-sized tricodonts could not compete with reptiles, so they did not spread widely.

Yura named after a French city located on the border with Switzerland. During this period, the planet was “conquered” by dinosaurs. They mastered not only land, water, but also air. There are currently 250 known species of dinosaurs. One of the most characteristic representatives of dinosaurs was the giant brachiosaurus. It reached a length of 30 m, weighed 50 tons, had a small head, a long tail and neck.

In the Jurassic period, various types of insects and the first bird appeared - Archeopteryx. Archeopteryx is the size of a crow. Its wings were poorly developed, it had teeth, and a long tail covered with feathers. In the Jurassic period of the Mesozoic there were many reptiles. Some of their representatives began to adapt to life in water.

The rather mild climate favored the development of angiosperms.

Chalk- the name was given because of thick chalk deposits formed from the remains of shells of small marine animals. During this period, angiosperms appear and spread extremely quickly, and gymnosperms are replaced.

The development of angiosperms during this period was associated with the simultaneous development of pollinating insects and insect-eating birds. Angiosperms have developed a new reproductive organ - a flower, which attracts insects with its color, smell and nectar reserves.

At the end of the Cretaceous period, the climate became colder, and the vegetation of the coastal lowlands died. Herbivores and predatory dinosaurs died along with the vegetation. Large reptiles (crocodile) are preserved only in the tropical zone.

In conditions of a sharply continental climate and general cooling, warm-blooded animals - birds and mammals - received exceptional advantages. The acquisition of viviparity and warm-bloodedness were the aromorphoses that ensured the progress of mammals.

During the Mesozoic period, the evolution of reptiles developed in six directions:

1st direction - turtles (appeared in the Permian period, have a complex shell fused with the ribs and breast bones);

5th direction - plesiosaurs (sea lizards with a very long neck, making up more than half of the body and reaching a length of 13-14 m);

6th direction - ichthyosaurs (lizard fish). The appearance is similar to a fish and a whale, short neck, fins, swim with the help of the tail, legs control the movement. Intrauterine development - live birth of offspring.

At the end of the Cretaceous period, during the formation of the Alps, climate change led to the death of many reptiles. During excavations, the remains of a bird the size of a pigeon, with the teeth of a lizard, which had lost the ability to fly, were discovered.

Aromorphoses that contributed to the appearance of mammals.

1. The increasing complexity of the nervous system and the development of the cerebral cortex influenced changes in animal behavior and adaptation to the living environment.

2. The spine was divided into vertebrae, the limbs were located from the abdominal part towards the back.

3. For intrauterine bearing of cubs, the female has developed a special organ. The cubs were fed milk.

4. To preserve body heat, hair appeared.

5. There was a division into the systemic and pulmonary circulation, and warm-bloodedness appeared.

6.Lungs have developed with numerous bubbles that enhance gas exchange.

1. Periods of the Mesozoic era. Triassic. Yura. Bor. Tricodonts. Dinosaurs. Archosaurs. Plesiosaurs. Ichthyosaurs. Archeopteryx.

2. Aromorphoses of the Mesozoic.

1.What plants were widespread in the Mesozoic? Explain the main reasons.

2. Tell us about the animals that developed in the Triassic.

1.Why is the Jurassic period called the period of dinosaurs?

2. Discuss aromorphosis, which is the cause of the appearance of mammals.

1. In what period of the Mesozoic did the first mammals appear? Why weren't they widespread?

2.Name the species of plants and animals that developed during the Cretaceous period.

In what period of the Mesozoic did these plants and animals develop? Opposite the corresponding plants and animals, put the capital letter of the period (T - Triassic, Y - Jurassic, M - Cretaceous).

1.Angiosperms.

2. Tricodonts.

4. Eucalyptus trees.

5. Archeopteryx.

6. Turtles.

7. Butterflies.

8. Brachiosaurs.

9. Hatterias.

11. Dinosaurs.

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