Mesozoic period 5. Mesozoic era, Mesozoic, all about the Mesozoic era, Mesozoic era, dinosaurs of the Mesozoic era

Lesson topic:"The development of life in Mesozoic era»

The duration of the Mesozoic era is approximately 160 million years. The Mesozoic era includes the Triassic (235-185 million years ago), Jurassic (185-135 million years ago) and Cretaceous (135-65 million years ago) periods. The development of organic life on Earth and the evolution of the biosphere continued against the background of paleogeographical changes characteristic of this stage.

The Triassic is characterized by a general rise of platforms and an increase in land area.

By the end of the Triassic, the destruction of most mountain systems that arose in the Paleozoic. The continents turned into huge plains, which were invaded by the ocean in the next, Jurassic, period. The climate became softer and warmer, covering not only the tropical and subtropical zones, but also modern temperate latitudes. During the Jurassic period the climate was warm and humid. The increased rainfall caused the formation of seas, huge lakes and large rivers. Changes in physical and geographical conditions affected the development of the organic world. The extinction of representatives of marine and terrestrial biota, which began in the arid Permian, continued, which was called the Permian-Triassic crisis. After this crisis and as a result of it, the flora and fauna of land evolved.

Biologically, the Mesozoic was a time of transition from old, primitive to new, progressive forms. The Mesozoic world was much more diverse than the Paleozoic; the fauna and flora appeared in it in a significantly updated composition.

Flora

The vegetation cover of the land at the beginning of the Triassic period was dominated by ancient conifers and seed ferns (pteridosperms). in arid climates, these gymnosperms gravitated towards moist places. On the coasts of drying reservoirs and in disappearing swamps, the last representatives of ancient club mosses and some groups of ferns perished. By the end of the Triassic, a flora was formed in which ferns, cycads, and ginkgos dominated. During this period they reached special prosperity gymnosperms.

In the Cretaceous, flowering plants appeared and conquered the land.

The putative ancestor of flowering plants, according to most scientists, was closely related to seed ferns and represented one of the branches of this group of plants. Paleontological remains of primary flowering plants and groups of plants intermediate between them and gymnosperm ancestors are, unfortunately, still unknown to science.

The primary type of flowering plant was, according to most botanists, an evergreen tree or low shrub. The herbaceous type of flowering plant appeared later under the influence of limiting environmental factors. The idea of ​​the secondary nature of the herbaceous type of angiosperms was first expressed in 1899 by the Russian botanical geographer A.N. Krasnov and the American anatomist C. Jeffrey.

The evolutionary transformation of woody forms into herbaceous ones occurred as a result of weakening, and then a complete or almost complete decrease in the activity of the cambium. This transformation probably began at the dawn of the development of flowering plants. Over time, it proceeded at a faster pace in the most distant groups of flowering plants and eventually acquired such a wide scale that it covered all the main lines of their development.

Neoteny, the ability to reproduce at an early stage of ontogenesis, was of great importance in the evolution of flowering plants. It is usually associated with limiting environmental factors - low temperature, lack of moisture and a short growing season.

Of the huge variety of woody and herbaceous forms, flowering plants turned out to be the only group of plants capable of forming complex multi-layered communities. The emergence of these communities led to a more complete and intensive use of the natural environment and the successful conquest of new territories, especially unsuitable for gymnosperms.

In the evolution and mass dispersal of flowering plants, the role of pollinating animals is also great. especially insects. By feeding on pollen, insects transferred it from one strobila of the original ancestors of angiosperms to another and were thus the first agents of cross-pollination. Over time, insects have adapted to eat ovules, causing significant harm to plant reproduction. The reaction to such a negative influence of insects was the selection of adaptive forms with closed ovules.

The conquest of land by flowering plants marks one of the decisive, turning-point factors in the evolution of animals. This parallelism in the suddenness and rapidity of the spread of angiosperms and mammals is explained by interdependent processes. The conditions with which the flourishing of angiosperms was associated were also favorable for mammals.

Fauna

Fauna of the seas and oceans: 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. Ammonites were found in such numbers in the Mesozoic that their shells are found in almost all marine sediments of this time.

By the end of the Triassic, most of the ancient groups of ammonites died out, but in the Cretaceous they remained numerous, but during the Late Cretaceous the number of species in both groups begins to decline. The diameter of some ammonite shells reaches 2.5 m.

At the end of the Mesozoic, all ammonites 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.

Six-rayed corals began to actively develop(Hexacoralla), whose colonies were active reef-formers. Mesozoic echinoderms were represented by various species of crinoids, or crinoids (Crinoidea), which flourished in the shallow waters of the Jurassic and partly Cretaceous seas. However the greatest progress has been achieved sea ​​urchins. Starfish were abundant.

Bivalve mollusks have also become widespread.

During the Jurassic period, foraminifera flourished again, survived the Cretaceous period and reached modern times. In general, single-celled protozoa were an important component in the formation of Mesozoic sedimentary rocks. The Cretaceous period was also a time of rapid development of new types of sponges and some arthropods, particularly insects and decapods.

The Mesozoic era was a time of unstoppable expansion of vertebrates. Of the Paleozoic fish, only a few transitioned into the Mesozoic. Among them were freshwater sharks, sea sharks continued to develop throughout the Mesozoic; Most modern genera were already represented in the Cretaceous seas, in particular.

Almost all lobe-finned fish, from which the first land vertebrates developed, became extinct in the Mesozoic. Paleontologists believed that lobe-finned animals became extinct by the end of the Cretaceous. But in 1938, an event occurred that attracted the attention of all paleontologists. An individual of a species of fish unknown to science was caught off the South African coast. Scientists who studied this unique fish came to the conclusion that it belongs to the “extinct” group of lobe-finned fish ( Coelacanthida). Until now this view remains the only modern representative of ancient lobe-finned fishes. It got the name Latimeria chalumnae. Such biological phenomena are called “living fossils.”

Sushi fauna: New groups of insects, the first dinosaurs and primitive mammals appeared on land. Reptiles became the most widespread in the Mesozoic, becoming truly the dominant class of this era.

With the advent of dinosaurs in Early reptiles became completely extinct in the mid-Triassic cotylosaurs and beast-like animals, as well as the last large amphibians, stegocephals. Dinosaurs, which represented the most numerous and diverse superorder of reptiles, became the leading Mesozoic group of terrestrial vertebrates starting from the end of the Triassic. For this reason, the Mesozoic is called the era of dinosaurs. 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.

The original ancestors of dinosaurs may have been the Upper Permian Eosuchians - a primitive order of small reptiles with a lizard-like physique. From them, in all likelihood, a large branch of reptiles arose - archosaurs, which then split into three main branches - dinosaurs, crocodiles and winged lizards. Representatives of archosaurs were thecodonts. Some of them lived in water and looked like crocodiles. Others, similar to large lizards, lived in open areas of land. These land-dwelling thecodonts adapted bipedal walking, which provided them with the ability to observe in search of prey. It was from these thecodonts, which became extinct at the end of the Triassic, that dinosaurs descended, inheriting a bipedal mode of locomotion, although some of them switched to a four-legged mode of locomotion. Representatives of the climbing forms of these animals, which over time moved from jumping to gliding flights, gave rise to pterosaurs (pterodactyls) and birds. Dinosaurs included both herbivores and carnivores.

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. The only known first bird was Archeopteryx. The remains of this first bird were found near the Bavarian city of Solnhofen (Germany). During the Cretaceous period, the evolution of birds was at a fast pace; characteristic of this time, still possessing jagged jaws. The emergence of birds was accompanied by a number of aromorphoses: they acquired a hollow septum between the right and left ventricles of the heart, and lost one of the aortic arches. The complete separation of the arterial and venous blood flows causes birds to be warm-blooded. Everything else, namely the feather cover, wings, horny beak, air sacs and double breathing, as well as shortening of the hindgut, are idioadaptations.

First mammals (Mammalia), 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. Their occurrence is associated with a number of major aromorphoses, developed in representatives of one of the subclasses of reptiles. These aromorphoses include: the formation of hair and a 4-chambered heart, complete separation of arterial and venous blood flows, intrauterine development of the offspring and feeding the baby with milk. Aromorphoses also include development of the cerebral cortex, which determines the predominance of conditioned reflexes over unconditioned ones and the possibility of adaptation to unstable environmental conditions by changing behavior.

Almost all Mesozoic groups of the animal and plant kingdoms retreat, die out, disappear; arises on the ruins of the old new world, the world of the Cenozoic era, in which life receives a new impetus for development and, in the end, living species of organisms are formed.

The history of the Earth goes back four and a half billion years. This huge period of time is divided into four eons, which in turn are divided into eras and periods. The final fourth eon - Phanerozoic - includes three eras:

• Paleozoic;
• Mesozoic;
• Cenozoic

significant for the appearance of dinosaurs, the emergence of the modern biosphere and significant geographical changes.

Periods of the Mesozoic era

The end of the Paleozoic era was marked by the extinction of animals. Development of life in Mesozoic era characterized by the emergence of new species of creatures. First of all, these are dinosaurs, as well as the first mammals.

The Mesozoic lasted one hundred eighty-six million years and consisted of three periods, such as:

• Triassic;
• Jurassic;
• chalky.

The Mesozoic period is also characterized as the era of global warming. There have also been significant changes in the tectonics of the Earth. It was at that time that the only existing supercontinent broke into two parts, which were subsequently divided into the continents that exist in the modern world.

Triassic

The Triassic period is the first stage of the Mesozoic era. The Triassic lasted for thirty-five million years. After the catastrophe that occurred at the end of the Paleozoic on Earth, conditions are observed that are little conducive to the flourishing of life. A tectonic fault occurs and active volcanoes and mountain peaks are formed.

The climate becomes warm and dry, as a result of which deserts form on the planet, and the level of salt in water bodies increases sharply. However, it is precisely at this unfavorable time that mammals and birds appear. This was largely due to the absence of clearly defined climatic zones and the maintenance of uniform temperatures throughout the territory globe.

Fauna of the Triassic

The Triassic period of the Mesozoic is characterized by significant evolution of the animal world. It was during the Triassic period that those organisms arose that subsequently shaped the appearance of the modern biosphere.

Cynodonts appeared - a group of lizards that were the ancestors of the first mammals. These lizards were covered with fur and had strong developed jaws what helped them eat raw meat. Cynodonts laid eggs, but females fed their young with milk. The ancestors of dinosaurs, pterosaurs and modern crocodiles - archosaurs - also arose in the Triassic.

Due to arid climate many organisms changed their habitat to aquatic. This is how new species of ammonites, mollusks, as well as bony and ray-finned fish appeared. But the main residents depths of the sea there were predatory ichthyosaurs, which, as they evolved, began to reach gigantic sizes.

By the end of the Triassic, natural selection did not allow all the animals that appeared to survive; many species could not withstand competition with others, stronger and faster. Thus, by the end of the period, thecodonts, the ancestors of dinosaurs, predominated on land.

Plants during the Triassic period

The flora of the first half of the Triassic did not differ significantly from the plants of the end of the Paleozoic era. They grew in abundance in the water different types algae, seed ferns and ancient conifers have become widespread on land, and in coastal areas- lycophytic plants.

By the end of the Triassic, the land was covered with a cover of herbaceous plants, which greatly contributed to the appearance of a variety of insects. Plants of the mesophytic group also appeared. Some cycad plants have survived to this day. It grows in the Malay Archipelago zone. Most plant species grew on the planet's coastal areas, while conifers predominated on land.

Jurassic period

This period is the most famous in the history of the Mesozoic era. The Jura is the European mountains that give its name to this time. Sedimentary deposits from that era have been found in these mountains. The Jurassic period lasted fifty-five million years. It acquired geographical significance due to the formation of modern continents (America, Africa, Australia, Antarctica).

The separation of the two previously existing continents of Laurasia and Gondwana served to form new bays and seas and raise the level of the world's oceans. This had a beneficial effect on making it more humid. The air temperature on the planet dropped and began to correspond to moderate and subtropical climate. Such climate changes greatly contributed to the development and improvement of flora and fauna.

Animals and plants of the Jurassic period

The Jurassic period is the era of dinosaurs. Although other forms of life also evolved and took on new forms and species. The seas of that period were filled with many invertebrates, the structure of whose bodies was more developed than in the Triassic. Have become widespread bivalves and intrashell belemnites, the length of which reached three meters.

The insect world has also received evolutionary growth. The appearance of flowering plants also provoked the appearance of pollinating insects. New species of cicadas, beetles, dragonflies and other terrestrial insects have emerged.

Climatic changes that occurred during the Jurassic period resulted in heavy rainfall. This, in turn, gave impetus to the spread of lush vegetation across the surface of the planet. In the northern belt of the earth, herbaceous ferns and ginkgo plants predominated. Southern belt were tree ferns and cycads. In addition, the Earth was filled with various coniferous, cordaite and cycad plants.

Age of Dinosaurs

IN Jurassic period During the Mesozoic era, reptiles reached their evolutionary peak, marking the beginning of the era of dinosaurs. The seas were dominated everywhere by giant dolphin-like ichthyosaurs and plesiosaurs. If ichthyosaurs were inhabitants of an exclusively aquatic environment, then plesiosaurs from time to time needed access to land.

Dinosaurs living on land amazed us with their diversity. Their sizes varied from 10 centimeters to thirty meters, and they weighed up to fifty tons. Herbivores predominated among them, but there were also ferocious predators. A huge number of predatory animals provoked the formation of certain elements of defense in herbivores: sharp plates, spines and others.

The airspace of the Jurassic period was filled with dinosaurs that could fly. Although they needed to climb to higher ground to fly. Pterodactyls and other pterosaurs swarmed and swooped above the surface of the earth in search of food.

Cretaceous period

When choosing a name for the next period main role played chalk, formed in the deposits of dying invertebrate organisms. The period called the Cretaceous was the final period of the Mesozoic era. This time lasted eighty million years.

The newly formed continents move, and the tectonics of the Earth increasingly takes on a form familiar to modern man. The climate became noticeably colder, at which time ice caps formed in the northern and south pole. The planet is also divided into climatic zones. But in general, the climate remained quite warm, helped by the greenhouse effect.

Cretaceous biosphere

Belemnites and mollusks continue to evolve and spread in water bodies, and sea urchins and the first crustaceans also develop.

In addition, fish with hard bones actively develop in reservoirs. Insects and worms have progressed greatly. On land, the number of vertebrates increased, among which the leading positions were occupied by reptiles. They actively consumed vegetation earth's surface and destroyed each other. During the Cretaceous period, the first snakes arose that lived both in water and on land. Birds, which began to appear at the end of the Jurassic period, became widespread and actively developed during the Cretaceous period.

Among vegetation, flowering plants have received the greatest development. Spore plants due to the characteristics of reproduction, they died out, giving way to more progressive ones. At the end of this period, gymnosperms evolved noticeably and began to be replaced by angiosperms.

The end of the Mesozoic era

The history of the Earth includes two events that contributed to the mass extinction of the planet's fauna. The first, the Permian catastrophe, marked the beginning of the Mesozoic era, and the second marked its end. Most animal species that actively evolved in the Mesozoic became extinct. Ammonites, belemnites, and bivalves ceased to exist in the aquatic environment. Dinosaurs and many other reptiles disappeared. Many species of birds and insects also disappeared.

To date, there is no proven hypothesis about what exactly was the impetus for the mass extinction of fauna in the Cretaceous period. There are versions about negative impact the greenhouse effect or radiation caused by a powerful cosmic explosion. But most scientists are inclined to believe that the cause of the extinction was the fall of a gigantic asteroid, which, when it hit the surface of the Earth, lifted a mass of substances into the atmosphere, blocking the planet from sunlight.

Parameter name	Meaning
Article topic:	Mesozoic era.
Rubric (thematic category)	Geology

The Mesozoic era, which lasts 183 million years, is divided into three periods - Triassic, Jurassic and Cretaceous. Accordingly, the Mesozoic group of deposits is divided into systems.

The Triassic system got its name due to the clear division of its sediments into three parts - Lower, Middle and Upper Triassic. Accordingly, the Triassic period (35.0 million years) is divided into three sections - early, middle And late.

In the Mesozoic, the continents of the Northern and Southern Hemispheres were separated by a vast sea basin elongated in the latitudinal direction. It got the name Tethys- in honor of the ancient Greek goddess of the sea.

At the beginning of the Triassic, powerful volcanic eruptions occurred in some areas of the globe. So, in Eastern Siberia outpourings of basaltic magma formed a layer of basic rocks, occurring in the form of huge covers. Such covers are called " traps" (Swedish " trap" - staircase). It is worth saying that they are characterized by columnar separation in the form of staircase steps. Volcanic eruptions also occurred in Mexico and Alaska, Spain and North Africa. IN Southern Hemisphere Triassic volcanism dramatically manifested itself in New Caledonia, New Zealand, the Andes and other areas.

During the Triassic, one of the largest sea regressions in Earth's history occurred. It coincided with the beginning of a new folding, which continued throughout the Mesozoic and was called “Mesozoic”. The folded structures that emerged at this time were called “mesozoid”.

The Jurassic system is named after the Jurassic Mountains in Switzerland. During the Jurassic period, which lasted 69.0 million years, a new transgression of the sea began. But at the end of the Jurassic, mountain-building movements resumed in the region of the Tethys Ocean (Crimea, Caucasus, Himalayas, etc.) and especially noticeably in the region of the Pacific margins. Οʜᴎ led to the formation of mountain structures of the outer Pacific ring: Verkhoyansk-Kolyma, Far Eastern, Andean, Cordilleran. The folding was accompanied by active volcanic activity. IN South Africa and South America (Parana River basin), large outpourings of basic trap lavas occurred at the beginning of the Jurassic period. The thickness of the basalt strata here reaches more than 1000 meters.

The Cretaceous system got its name due to the fact that layers of white chalk are widespread in its sediments. The Cretaceous period lasted 79.0 million years. Its beginning coincided with an extensive marine transgression. According to one hypothesis, the northern supercontinent Laurasia at that time broke up into a number of separate continents: East Asian, North European, North American. Gondwana also split into separate continental masses: South American, African, Indian, Australian and Antarctic. In the Mesozoic, perhaps all modern oceans were formed, except, apparently, the more ancient one Pacific Ocean.

In the Late Cretaceous era, a powerful phase of Mesozoic folding appeared in areas adjacent to the Pacific Ocean. Less intense mountain-building movements at this time occurred in a number of areas of the Mediterranean region (Eastern Alps, Carpathians, Transcaucasia). As in the Jurassic period, folding was accompanied by intense magmatism.

Mesozoic rocks are “pierced” by granite intrusions embedded in them. And on the vast expanses of the Siberian, Indian, African-Arabian platforms at the end of the Mesozoic there were enormous outpourings of basaltic lavas that formed trap covers (Swedish ʼʼ trapʼʼ - ladder). Now they come to the surface, for example, along the banks of the river Lower Tunguska. Here you can observe the remains of solid basalts, rising several hundred meters high, which were previously embedded in sedimentary rocks, destroyed after reaching the surface by the processes of weathering and erosion. Vertical ledges of black (dark gray) traps, called “pillars,” alternate with horizontal platforms. This is why climbers and tourists fell in love with them. The thickness of such covers on the Deccan Plateau in Hindustan reaches 2000-3000 m.

ORGANIC WORLD M is ozoic. At the turn of the Paleozoic and Mesozoic eras, the flora and fauna were significantly renewed (Fig. 14, 15). The Triassic period is characterized by the appearance in the seas of new cephalopods (ammonnites, belogemnites) and elasmobranch mollusks, six-rayed corals and other groups of animals. Bony fish appeared.

On land it was a time of reptile dominance. New groups of them arose - the first lizards, turtles, crocodiles, snakes. At the beginning of the Mesozoic, the first mammals appeared - small marsupials the size of a modern rat.

In the Triassic - Jurassic, belemnites, giant herbivorous and predatory reptile lizards - dinosaurs (Greek "dinos" - terrible, "savros" - lizard) appeared and flourished. They reached a length of 30 m or more and weighed up to 60 tons. Dinosaurs (Fig. 16) mastered not only land, but also the sea. Ichthyosaurs lived here (Greek “ichthys” - fish) - large predatory fish lizards that reached a length of more than 10 m and resembled modern dolphins. At the same time, the first flying lizards appeared - pterosaurs (Greek "pteron" - wing), "savros" - lizard). These were mostly small (up to half a meter) reptiles adapted to flight.

Common representatives of pterosaurs were flying lizards - rhamphorhynchus (Greek rhamphos - beak, rhinos - nose) and pterodactyls (Greek pteron - feather, dactylos - finger). Their forelimbs turned into flying organs - membranous wings The main food of rhamphorhynchus was fish and insects. The smallest pterodactyls were the size of a sparrow, the largest reached the size of a hawk.

Flying lizards were not the ancestors of birds. Οʜᴎ represent a special, independent evolutionary branch of reptiles, which completely died out at the end of the Cretaceous period. Birds evolved from other reptiles.

The very first bird, apparently, is Archeopteryx (Greek “archeos” - ancient, “pteron” - wing). It was a transitional form from reptiles to birds. Archeopteryx was the size of a crow. He had short wings, sharp carnassial teeth And a long tail with fan-shaped plumage. The body shape, structure of the limbs and the presence of plumage were similar to Archeopteryx birds. But in a number of ways it was still close to reptiles.

Remains of primitive mammals were discovered in Jurassic deposits.

The Cretaceous period is the time of greatest flowering of reptiles. Dinosaurs reached enormous sizes (up to 30 m in length); their mass exceeded 50 tons. They widely populated land and waters and reigned in the air. During the Cretaceous period, flying lizards reached gigantic sizes - with a wingspan of about 8 m.

Gigantic sizes were characteristic of some other groups of animals in the Mesozoic. Thus, in the Cretaceous seas there were mollusks - ammonites, whose shells reached a diameter of 3 m.

Of the plants on land, starting from the Triassic period, gymnosperms predominated: conifers, gingkovae, etc.; of the spore plants - ferns. During the Jurassic period, terrestrial vegetation developed rapidly. At the end of the Cretaceous period, angiosperms appeared; grass cover formed on the land.

At the end of the Cretaceous period, the organic world again underwent dramatic changes. Many invertebrates and most giant lizards became extinct. The reasons for their extinction have not been reliably established. According to one hypothesis, the death of dinosaurs is associated with a geological catastrophe that occurred about 65 million years ago. It is believed that a large meteorite collided with the Earth at that time.

In the 70s of the twentieth century. University of California geologist Walter Alvarez and

his father, physicist Luis Alvarez, discovered an unusually high content of iridium, an element found in large quantities in meteorites, in the Cretaceous-Paleogene boundary deposits of the Gubbio section (Italy). Anomalous iridium content was also discovered at the Cretaceous-Paleogene boundary in other

areas of the globe. In this regard, father and son Alvarez put forward a hypothesis about the collision of a large cosmic body of asteroid size with the Earth. The consequence of the collision was the mass extinction of Mesozoic plants and animals, in particular dinosaurs. This happened about 65 million years ago at the turn of the Mesozoic and Cenozoic eras.
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At the moment of the collision, myriads of meteorite particles and terrestrial matter rose into the sky in a giant cloud and obscured the Sun for years. The earth plunged into darkness and cold.

In the first half of the 80s, numerous geochemical studies were carried out. They showed that the iridium content in the Cretaceous-Paleogene boundary deposits is indeed very high - two to three orders of magnitude higher than its average content (clarke) in the earth's crust.

At the end of the late disappeared and large groups higher plants.

USEFUL AND RESOURCED MEZOZONES.

Mesozoic sediments contain many minerals. Deposits of ore minerals were formed as a result of basaltic magmatism.

The widespread Triassic weathering crust contains deposits of kaolin and bauxite (Ural, Kazakhstan). During the Jurassic and Cretaceous periods, powerful coal accumulation occurred. In Russia, deposits of Mesozoic brown coals are located within the Lena, South Yakut, Kansko-Achinsk, Cheremkhovo, Chulym-Yenisei, Chelyabinsk basins, Far East and in other areas.

The famous oil and gas fields of the Middle East, Western Siberia, as well as Mangyshlak, Eastern Turkmenistan and Western Uzbekistan are confined to Jurassic and Cretaceous deposits.

During the Jurassic period, oil shale (Volga region and General Syrt), sedimentary iron ores (Tula and Lipetsk regions), and phosphorites (Chuvashia, Moscow region, General Syrt, Kirov region) were formed.

Phosphorite deposits are confined to the Cretaceous deposits (Kursk, Bryansk, Kaluga, etc.
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region) and bauxite (Hungary, Yugoslavia, Italy, France). Deposits of polymetallic ores (gold, silver, copper, lead, zinc, tin, molybdenum, tungsten, etc.) are associated with chalk granite intrusions and basaltic outpourings. This is, for example, Sadonskoe ( North Caucasus) deposit of polymetallic ores, tin ores of Bolivia, etc. Two rich Mesozoic ore belts stretch along the shores of the Pacific Ocean: from Chukotka to Indochina and from Alaska to Central America. In South Africa and Eastern Siberia, diamond deposits are confined to Cretaceous deposits.

Cenozoic era. The Cenozoic era lasts 65 million years. On the international geological time scale, it is divided into “Tertiary” and “Quaternary” periods. In Russia and other countries of the former Soviet Union The Cenozoic is divided into three periods: Paleogene, Neogene and Anthropogene (Quaternary).

The Paleogene period (40.4 million years) is divided into early - Paleocene (10.1 million years), middle - Eocene (16.9 million years) and late - Oligocene (13.4 million years) era. In the Northern Hemisphere in the Paleogene there existed the North American and Eurasian continents. They were separated by a depression Atlantic Ocean. In the Southern Hemisphere, the continents continued to develop independently, breaking away from Gondwana and separated by the Atlantic and Indian Oceans.

In the Eocene era, the first phase of powerful Alpine folding appeared in the Mediterranean region. It caused the uplift of some central sections of this area. By the end of the Paleogene, the sea completely left the territory of the Himalayan-Indian part of Tethys.

The formation of numerous deep faults in the North Channel and adjacent areas of Ireland, Scotland, Northern England and the Hebrides; the region of Southern Sweden and the Skagerrak, as well as throughout the entire North Atlantic region (Spitsbergen, Iceland, Western Greenland) contributed to basaltic outpourings.

At the end of the Paleogene period, fault and block movements became widespread in many parts of the globe. earth's crust. In a number of areas of the Western European Hercynides, a graben system arose (Upper Rhine, Lower Rhine). A system of narrow meridionally elongated grabens (Dead and Red Seas, Lakes Alberta, Nyasa, Tanganyika) arose in the eastern part of the African Platform). It stretches from the northern edge of the platform almost to the extreme south at a distance of over 5000 km. Fault dislocations here were accompanied by enormous outpourings of basaltic magmas.

The Neogene period includes two eras: early - Miocene (19.5 million years) and late - Pliocene (3.5 million years). It is worth saying that the Neogene was characterized by active mountain formation. By the end of the Neogene, alpine folding turned most of the Tethys region into the youngest alpine folded region in the structure of the earth's crust. At this time we purchased our modern look many mountain structures. Chains of the Sunda, Moluccas, New Guinea, New Zealand, Philippine, Ryukkyu, Japanese, Kuril, Aleutian islands and others arose.
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Within the East Pacific coastal margins, coastal ridges rose in a narrow strip. Mountain formation also occurred in the region of the Central Asian mountain belt.

Powerful block movements caused the subsidence of large sections of the earth's crust in the Neogene - areas of the Mediterranean, Adriatic, Black, East China, South China, Japan, Okhotsk and other marginal seas, as well as the Caspian Sea.

The rise and fall of crustal blocks in the Neogene were accompanied by

the origin of deep faults. Lava flowed through them. Eg,

in the Central Plateau region of France. In the zone of these faults, the volcanoes Vesuvius and Etna, as well as the Kamchatka, Kuril, Japanese and Javan volcanoes, arose in the Neogene.

In the history of the Earth, there have been frequent periods of cooling, alternating with warming. About 25 million years ago, from the end of the Paleogene, a cooling event occurred. One of the warmings took place at the beginning of the Late Neogene (Pliocene era). The next cold snap formed mountain-valley and sheet glaciers in the northern hemisphere and a thick ice sheet in the Arctic. Long-term freezing of rocks in northern Russia continues to this day.

The Anthropogenic period got its name because at the beginning of this period man appeared (Greek . "anthropos" - man). Its former name is quaternary system. The question of the duration of the Anthropocene period has not yet been finally resolved. Some geologists estimate the duration of the Anthropocene to be at least 2 million years. Anthropocene is divided into Eopleistocene(Greek "Eos" - dawn, "pleistos" - greatest, "kainos" - new), Pleistocene And Holocene(Greek "voice" - all, "kainos" - new). The duration of the Holocene does not exceed 10 thousand years. But some scientists classify the Eopleistocene as the Neogene and place the lower boundary of the Anthropocene at 750 thousand years ago.

At this time, the uplift of the Central Asian mountain fold belt continued more actively. According to some scientists, the mountains of the Tien Shan and Altai rose several kilometers during the Anthropocene period. And the depression of Lake Baikal sank to 1600 m.

Intense volcanic activity manifests itself in the Anthropocene. The most powerful basaltic outpourings in modern times have been observed at mid-ocean ridges and other vast areas of the ocean floor.

“Great” glaciations occurred over vast areas of the northern continents during the Anthropocene period. They also formed the Antarctica ice sheet. The Eopleistocene and Pleistocene are characterized by a general cooling of the Earth's climate and the periodic occurrence of continental glaciations in mid-latitudes. In the Middle Pleistocene, powerful glacial tongues descended to almost 50° N latitude. in Europe and up to 40° N. in USA. Here the thickness of moraine deposits is a few tens of meters. Interglacial eras were characterized by a relatively mild climate. Average temperatures increased by 6 - 12° C (N.V. Koronovsky, A.F. Yakushova, 1991). .

Formed by the waters of the seas and oceans, huge masses of ice in the form of glaciers advanced onto land. Frozen rocks spread over vast areas. Holocene - post-glacial era. Its beginning coincides with the end of the last continental glaciation of Northern Europe.

ORGANIC WORLD ZOOS. By the beginning of the Cenozoic era, belemnites, ammonites, giant reptiles, etc. died out.
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In the Cenozoic, protozoa (foraminifera), mammals and bony fish began to actively develop. They took a dominant position among other representatives of the animal world. In the Paleogene, oviparous and marsupials predominated among them (a fauna of this type was partially preserved in Australia). In the Neogene, these groups of animals receded into the background and the main role began to be played by ungulates, proboscis, predators, rodents and other currently known classes of higher mammals.

Organic world Anthropocene is similar to modern. During the Anthropocene period, humans evolved from primates that existed in the Neogene 20 million years ago.

The Cenozoic era is characterized by a wide distribution of terrestrial vegetation: angiosperms, grasses close to modern ones.

USEFUL AND FOUNDATIONS. During the Paleogene period, powerful coal formation occurred. Brown coal deposits are known in the Paleogene of the Caucasus, Kamchatka, Sakhalin, USA, South America, Africa, India, Indochina, Sumatra. Paleogne manganese ores have been identified in Ukraine (Nikopol), Georgia (Chiatura), the North Caucasus, and Mangyshlak. Paleogene deposits of bauxite (Chulymo-Yenisei, Akmola), oil and gas are known.

Oil and gas deposits are confined to Neogene deposits (Baku, Maykop, Grozny, Southwestern Turkmenistan, Western Ukraine, Sakhalin). In the Black Sea basin, on the territory of the Kerch and Taman Peninsulas, during the Neogene period, precipitation of iron ores occurred in various areas.

During the Anthropogen period, deposits of salts, building materials (crushed stone, gravel, sand, clay, loam), lake-marsh iron ores were formed; as well as placer deposits of gold, platinum, diamonds, tin, tungsten ores, precious stones and etc.

Table 5

Mesozoic era. - concept and types. Classification and features of the category "Mesozoic era." 2017, 2018.

Eona. The Mesozoic consists of three periods- Cretaceous, Jurassic and Triassic. The Mesozoic era lasted for 186 million years, starting 251 million years ago and ending 66 million years ago. To avoid confusion in eons, eras and periods, use as a visual clue geochronological scale, which is located .

The lower and upper boundaries of the Mesozoic are defined by two mass extinctions. The lower limit is marked by the largest extinction in the history of the Earth - the Permian or Permian-Triassic, when about 90-96% of marine animals and 70% of terrestrial animals disappeared. The upper limit is marked by perhaps the most famous extinction event - the Cretaceous-Paleogene, when all the dinosaurs became extinct.

Periods of the Mesozoic era

1. or Triassic period. Lasted from 251 to 201 million years ago. The Triassic is known for the fact that during this period the mass extinction ends and the gradual restoration of the Earth's fauna begins. Also in the Triassic period, the largest supercontinent in history, Pangea, begins to break apart.

2. or Jurassic period. Lasted from 201 to 145 million years ago. Active development plants, marine and terrestrial animals, giant dinosaurs and mammals.

3. or Cretaceous period. Lasted from 145 to 66 million years ago. The beginning of the Cretaceous period is characterized further development flora and fauna. Large reptile dinosaurs reigned on the earth, some of which reached 20 meters in length and eight meters in height. The mass of some dinosaurs reached fifty tons. The first birds appeared in the Cretaceous period. At the end of the period, the Cretaceous disaster occurred. As a result of this disaster, many species of plants and animals disappeared. The most big losses found themselves among the dinosaurs. At the end of the period, ALL dinosaurs became extinct, as well as many gymnosperms, many aquatic reptiles, pterosaurs, ammonites, as well as 30 to 50% of all animal species that were able to survive.

Animals of the Mesozoic era

Apatosaurus

Archeopteryx

Askeptosaurus

Brachiosaurus

Diplodocus

Sauropods

Ichthyosaurs

Camarasaurus

Liopleurodon

Mastodonsaurus

Mosasaurs

Nothosaurs

Plesiosaurs

Sclerosaurus

Tarbosaurus

Tyrannosaurus

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Mesozoic era

Mesozoic(Mesozoic era, from Greek μεσο- - “middle” and ζωον - “animal”, “ Living being") - a period of time in the geological history of the Earth from 251 million to 65 million years ago, one of the three eras of the Phanerozoic. First isolated in 1841 by British geologist John Phillips.

The Mesozoic is an era of tectonic, climatic and evolutionary activity. The formation of the main contours of modern continents and mountain building on the periphery of the Pacific, Atlantic and Indian oceans is taking place; the division of land facilitated speciation and other important evolutionary events. The climate was exceptionally warm throughout the entire time period, which also played an important role in the evolution and formation of new animal species. By the end of the era, the bulk of the species diversity of life approached its modern state.

Geological periods

Following Paleozoic era, the Mesozoic extends in time for about 180 million years: from 251 million years ago to the beginning of the Cenozoic era, 65 million years ago. This period is divided into three geological periods, in the following order (beginning - end, million years ago):

• Triassic period (251.0 - 199.6)
• Jurassic period (199.6 - 145.5)
• Cretaceous period (145.5 - 65.5)

Nizhny (between Perm and Triassic periods, that is, between the Paleozoic and Mesozoic), the boundary is marked by the Permo-Triassic mass extinction, which resulted in the death of approximately 90-96% of marine fauna and 70% of land vertebrates. The upper limit is set at the Cretaceous-Paleocene boundary, when another very large extinction of many groups of plants and animals occurred, most often attributed to the impact of a giant asteroid (Chicxulub crater on the Yucatan Peninsula) and the subsequent “asteroid winter”. Approximately 50% of all species became extinct, including all dinosaurs.

Tectonics

Climate

Warm climate, close to modern tropical

Flora and fauna

Scheme of the evolution of flora and fauna in the Mesozoic era.

Links

Wikimedia Foundation.

• 2010.
• Mesoamerican writing systems

Mesokaryotes

See what the “Mesozoic era” is in other dictionaries:- (secondary Mesozoic era) in geology, the period of the existence of the globe, corresponding to the deposits of the Triassic, Jurassic and Cretaceous; character. abundance and diversity of reptiles, most of which have become extinct. Dictionary foreign words, included in ... ... Dictionary of foreign words of the Russian language

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Mesozoic era- (Mesozoic) Mesozoic, the geological era between the Paleozoic and Cenozoic eras, including the Triassic, Jurassic and Cretaceous periods, lasted from approximately 248 to 65 million years ago. It was a time of abundance of vegetation and predominance... ... Countries of the world. Dictionary

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Mesozoic era- The era that replaced the Paleozoic in the history of the Earth’s development; began 248 million years ago and preceded the Cenozoic era. It is divided into three periods: Triassic, Jurassic and Cretaceous. [Dictionary of geological terms and concepts. Tomsky... ... Technical Translator's Guide

Books

• Dinosaurs. Complete encyclopedia, Green Tamara. Dinosaurs are interesting to readers of absolutely all ages. This is also a favorite children's theme, as evidenced by numerous cartoons and, of course, the now classic film 'Park...'