In what era of Puerozoa is the longest period. Periods of geological history of land in chronological order

Life on Earth originated over 3.5 billion years ago, immediately after the completion of the formation earth crust. Throughout the time, the emergence and development of living organisms influenced the formation of relief, climate. Also, tectonic, and climatic changes occurring over the years have influenced the development of life on earth.

The development table on Earth can be drawn up, based on the chronology of events. The entire history of the Earth can be divided into certain stages. The largest of them are era of life. They are divided into era, the era - on-of the era, the epoch - for the century.

Era of life on earth

The entire period of living on Earth can be divided into 2 periods: Precambria, or cryptose (primary period, 3.6 to 0.6 billion years), and plywood.

Cryptose includes the Archean (ancient life) and the Proterozoic (primary life) of the era.

Phaneroza includes Paleozoic (ancient life), Mesozoic (middle life) and Cenozoic ( new life) Era.

These 2 periods of development of life are customary to divide into smaller - era. The boundaries between the eras are global evolutionary events, extinction. In turn, the era are divided for periods, periods - to the epochs. The history of life development on earth is associated directly with changes in the earth's crust and climate of the planet.

Development era, time countdown

The most significant events are made to allocate in special time intervals - era. The time countdown is carried out in reverse order, from the most ancient life to the new one. There are 5 er:

1. Archean.
2. Proterozoic.
3. Paleozoic.
4. Mesozoic.
5. Cenozoic.

Periods of development of life on earth

Paleozoic, Mesozoic and Cenozoic era include periods of development. These are more small segments of time, compared to the eras.

Palaeozoic:

• Cambrian (Cambrí).
• Ordovican.
• Silurian (silicon).
• Devonian (Devon).
• Coal (carbon).
• Perm (Perm).

Mesozoic Era:

• Triassic (TRIAS).
• Jurassic (Yura).
• Chalk (chalk).

Cenozoic Era:

• Low-formile (Paleogen).
• Upperretical (neogen).
• Quaternary, or anthropogen (human development).

The first 2 periods are included in the tertiary period of 59 million years.

Development of living organisms

The development table of life on Earth involves division not only for temporary intervals, but also on certain stages of the formation of living organisms, possible climatic changes (the ice age, global warming).

• Archean era. The most significant changes in the evolution of living organisms are the emergence of blue-green algae - prokaryotes capable of breeding and photosynthesis, the emergence of multicellular organisms. The emergence of living protein substances (heterotrophs) capable of absorbing dissolved in water organic substances. In the future, the emergence of these living organisms made it possible to divide the world on floral and animal.

• Mesozoic era.

• Triassic. The propagation of plants (voted). An increase in the amount of reptiles. The first mammals, bone fish.
• Jurassic period. The predominance of voted, the occurrence of coated bridges. The appearance of a leader, flourishing challenges of mollusks.
• Cretaceous period. Distribution of coated bridge, reducing other plant species. Development of bone fish, mammals and birds.

• Cenozoic era.
  • Lower builder (Paleogen). The flourishing coated bridge. The development of insects and mammals, the appearance of lemurs, later primates.
  • Upperretic period (neogen). The formation of modern plants. The appearance of the ancestors of people.
  • Quaternary period (anthropogen). The formation of modern plants, animals. The emergence of man.

Development of conditions of inanimate nature, climate change

The development table of life on earth cannot be represented without data on changes in inanimate nature. The emergence and development of life on Earth, new types of plants and animals, all this is accompanied by changes and in inanimate nature, climate.

Climatic changes: Archean Era

The history of life development on Earth began through the stage of the prevalence of sushi over water resources. The relief was poorly discharged. The atmosphere prevails carbon dioxide, the amount of oxygen is minimal. In shallow water reduced salinity.

For the Archean era, the eruption of volcanoes, lightning, black clouds is characteristic. Mountain breeds are rich in graphite.

Climatic changes to the Proterozoic Era

Sushha is a stone desert, all living organisms inhabit the water. Oxygen accumulates in the atmosphere.

Climatic changes: Paleozoic era

In different periods paleozoic era The following happened:

• Cambrian period. Susha is still deserted. The climate is hot.
• Ordigrian period. The most significant changes are the flooding of almost all northern platforms.
• Silurian. Textical changes, conditions of inanimate nature are diverse. Gorical formation occurs, the seas are dominated over land. The areas of different climates are identified, including areas of cooling.
• Devonian. Dry climate predominates, continental. Education of intermountain depression.
• Coal period. Lowering mainland, wetlands. Warm and wet climate, in the atmosphere, many oxygen and carbon dioxide.
• Perm period. Hot climate, volcanic activity, minority, drying of swamps.

Mountains were formed in the era of Paleozoa. Such changes in the relief influenced the world ocean - marine pools declined, a significant land area was formed.

Paleozoic Era laid the beginning of almost all major fields of oil and stone coal.

Climatic changes in Mesozoic

For the climate of various periods of Mesozoic, the following features are characteristic:

• Triassic. Volcanic activity, climate sharply continental, warm.
• Jurassic period. Soft and warm climate. The sea is dominated over land.
• Cretaceous period. The retreat of the seas from sushi. The climate is warm, but at the end of the period, global warming is replaced by cooling.

In the Mesozoic era, the mining systems formed earlier are destroyed, the plains go under water ( Western Siberia). In the second half of the era, Cordillera, Mountains of Eastern Siberia, Indochina, Partly Tibet, formed Mesozoic Folding Mountains were formed. A hot and humid climate prevails, which contributes to the formation of swamps and peatlands.

Climatic Changes - Cenozoic Era

In the Cenozoic Era, there was a general lift of the earth's surface. Climate changed. Numerous glands of earthly covers of the coming from the north changed the appearance of the continents of the northern hemisphere. Thanks to such changes, hilly plains were formed.

• Lower builder. Mild climate. Separation by 3. climatic zones. Formation of continents.
• Upperretic period. Dry climate. The emergence of steppes, savannah.
• Quaternary period. Multiple glaciation of the northern hemisphere. Climate cooling.

All changes throughout the development of life on Earth can be written in the form of a table, which will reflect the most significant stages in the formation and development modern Mira. Despite the already well-known research methods, and now scientists continue to study history, make new discoveries that allow modern society Find out how life has developed on Earth before the appearance of a person.

Geological chronology, or geochronology, it is based on the clarification of the geological history of the most well-studied regions, for example, in the central and Eastern Europe. Based on broad generalizations, comparison of the geological history of various regions of the Earth, the patterns of evolution organic World At the end of the last century, an international geochronological scale was developed and adopted at the first international geological congresses, which reflects the sequence of time divisions during which certain sets of deposits were formed, and the evolution of the organic world. Thus, the international geochronological scale is the natural periodization of the history of the Earth.

Among the geochronological divisions are allocated: Eon, Era, period, era, century, time. Each geochronological unit corresponds to the deposit complex allocated in accordance with the change in the organic world and called stratigraphic: eonothem, group, system, department, tier, zone. Consequently, the group is a stratigraphic unit, and the corresponding temporary geochronological unit represents the era. Therefore, there are two scales: geochronological and stratigraphic. The first is used when they talk about relative time in the history of the Earth, and the second, when they deal with deposits, as some geological events occurred in every place of the globe. Another thing is that the accumulation of precipitation was uncommon.

• The Archean and Proterozoic Eonothemes, covering almost 80% of the existence of the Earth, are distinguished in cryptosis, since the skeletal fauna and the paleontological method for their dismemberment are completely absent in the Precontal Education. Therefore, the separation of Precambrian formations is based primarily on the general and radiometric data.
• Puerozoic Eon covers only 570 million years and the dismemberment of the corresponding sediment eonothem is based on a large variety of numerous skeletal fauna. Puerozoic Eonothem is divided into three groups: Paleozoic, Mesozoic and Cenozoic, which meet the major stages of the natural geological history of the Earth, the frontiers of which are noted by rather sharp changes in the organic world.

The names of the Eonothem and Group originate from the Greek words:

• "Archaeos" is the most ancient, oldest;
• "Proteros" - primary;
• "Paleos" - ancient;
• "Mesos" - medium;
• "Kaynos" - new.

The word "cryptos" means hidden, and "plywood" is clear, transparent, as skeletal fauna appeared.
The word "Zoya" comes from Zoikos - life. Consequently, the "Cenozoic Era" means the era of a new life, etc.

Groups are divided into systems, whose deposits were formed during one period and are characterized only by them inherent families or birth of organisms, and if these are plants, and species and species. Systems were allocated in various regions and at different times, starting from 1822. Currently, 12 systems are allocated, the names of most of which occur from those places where they were first described. For example, the Jurassic system is from the Jurassic Mountains in Switzerland, Perm - from the Perm province in Russia, chalk - on the most characteristic breeds - white letter of chalk, etc. The quaternary system is often called anthropogenova, since it is in this age interval a person appears.

Systems are divided into two or three departments, which correspond to the early, medium, late epochs. Departments, in turn, are divided into tiers, which are characterized by the presence of certain kinds and types of fossil fauna. And finally, tiers are divided into zones that are the most fractional part International Stratigraphic Scale, which in a geochronological scale corresponds to time. Target names are usually given by geographical names districts where this tier was allocated; For example, Alandansky, Bashkir, Maastricht tiers, etc. At the same time, the zone is denoted by the most characteristic type of fossil fauna. The zone covers, as a rule, only a certain part of the region and is developed on a smaller area, rather than the deposits of the tier.

All divisions of the stratigraphic scale correspond to the geological cuts in which these units were first allocated. Therefore, such cuts are reference, typical and called stratoids, which contain only a complex of organic residues, which determines the stratigraphic volume of this strata. The determination of the relative age of any layers is compared to the detected complex of organic residues in the studied layers with the complex of fossil in the abolition of the corresponding division of the international geochronological scale. The age of deposits is determined relative to the passionithip. That is why the paleontological method, despite its inherent flaws, remains the most important method for determining geological age mountain breeds. The definition of relative age, for example, Devonian deposits, is only indicated that these deposits are younger silurian, but ancient coal. However, to establish the duration of the formation of Devonian deposits and to make a conclusion about when (in absolute summer) there was an accumulation of these sediments - it is impossible. Only the methods of absolute geochronology are able to answer this question.

Tab. 1. Geochronological table

The problem of determining the absolute age of rocks, the duration of the existence of the Earth has long been occupied by the minds of geologists, and attempts to solve it were made many times for which they were used various phenomena and processes. Early ideas about the absolute age of land were curious. Contemporary M. V. Lomonosov French Naturalist Proteler Buffon defined the age of our planet only 74,800 years. Other scientists gave various figures not exceeding 400-500 million years. It should be noted here that all these attempts were doomed to failure in advance, since they proceeded from the constancy of the speeds of processes, which, as we know, changed in the geological history of the Earth. And only in the first half of the XX century. There was a real opportunity to measure the absolute age of rock, geological processes and land as the planet.

On the structure, properties and behavior ocean crust Classical geology practically did not have information that it extremely difficult to understand the movements of the earth's crust in general or, as they say, the global tectonics of the Earth. Now building the historical geology of the ocean bark (and thus the earth's crust as a whole) has already begun, in connection with which the building created by the classics is the building of modern geology exposed to a revolutionary restructuring. Consider the basic information of the classical historical geology of Puerozoos.

The term plywood (from the Greek Words of Plyeros - Obvious, Zoe - Life) was introduced by Chadvik in 1930. The share of the Precambrian breeds in the outcrops on the surface of the Earth is small, in the outcrops, which were known to the geologists of the XIX century, it was practically equal to zero, so that For them, Puerozoic breeds exhaust the entire geological chronicle. Already Arduino (1759) proposed to share these breeds by the degree of their antiquity of PA primary, secondary and tertiary (the last of these terms has been preserved and now, it is used for the name of the first period cenozoic era). The dismemberment of the Puerozoic for three era - ancient life (Paleozoa, PZ, duration of 340 million years old), high-life (mezogo, MZ, duration of 163 million years) and a new life (Cenozoa, KZ, the last 67 million years old until our time ) - J. Phillips was finally introduced. From a biological point of view, Paleozoa can be briefly characterized as the era of the domination of sea invertebrates, fish and amphibians, mesozoic - reptiles and cynose - mammals.

The eras are divided for periods, periods - on the epochs, epochs - for centuries; There are even smaller units. All of them are given the names mainly in areas in which the most vivid or typical outcrops of the corresponding sedimentary layers were met. The generalizing column "Tasce with Petrosets" was first suggested by Charles Layel in 1839

In the future, the dismemberment of the three ER puerozoosa for geological periods was repeatedly revised, until the modern nomenclature was formed in Table. 5. The tertiary period is divided into Paleogenic and non -ogenic (in Table 5, era are also indicated); Coal (carbon) - on Pennsylvania and Mississipa-sky. The table also shows the applied abbreviated designations of the ER and periods. Finally, it presents the absolute age of the borders between periods in millions of years (and in brackets after the names of the ER and periods - their duration), determined by the potassium-argon method and approved by the International Geochronological Commission in 1965 (we note that the first absolute age scale geological periods Fuelozoa was compiled by A. Holmes but the lead method in 1947; The modern scale differs from it only a little). Dadim now brief description Each of the geological periods starting from the most ancient.

Cambrian was highlighted by the English geologist A. Sedgevik in 1835, named the ancient name of the English province of Wales, where the ancient shale of this period are found. In the Precambrian time, at the end of the vendent, the territory of modern continents were mainly drained (as they say, Vennd was theocratic era), and the beginning of the Cambrian was marked by the extensive onset of the sea (transgression), then changed in the middle of the period by some retreat (regression) during the Saalairskoy Tectono -Magmatic era. If the Precambrian (Venndskaya) fauna was crucial, animals with skeletons, sinks and shells appeared in Cambrian. Special development TriLobites - a subclass of marine arthropods, subsequently extinct, sizes 2-10 cm, sometimes up to 75 cm (from now existing animals on them more like representatives of the sludge, so-called Kingkrabs). For the early Cambrian, similar to the sponges of rhyme-forming animals with a lime skeleton of archelate are characterized. We mention more with a benchfield with a double sink and a number of other animals.

The Ordovik was introduced as the lower era of the Silura English geologist R. Murchison in 1835; The name is proposed by Laovors (4879) but the ancient Celtic tribe of Ordovikov, who inhabited Northern Wales during the Roman Empire; In Wales there are gravel tolls of this period; As an independent period, approved only in 1960 (21st sessions of the International Geological Congress). Its first half was marked by the vast transgression of the sea, as a result of which the middle of the Ordovik turned out to be a thalassomocratic epoch; During this era, the largest part of the area of \u200b\u200bmodern continents was under water under water. The end of the Ordovka was marked by the regression of the sea. From animals along with trilobites, brachopo-dami, cephalmis, primitive needle-skinned cystoids of widespread development reached grapetoli - you are subsequently extinct bottom and floating colonial marine animals with a chitin-like shell forming the subtype in the type of semi-ferrous (from nype of living organisms to them closest Called rattopaber).

The silicon was introduced by R. Murchison in 1835, named the ancient Celtic tribe of the Silurists who inhabited Shropshire in Wales (sometimes called Gotlaptius for about. Gotland in the Baltic Sea, where there are capacious rocks of this period). In the lower silver there was a major transgression of the sea, replaced in the upper silver of almost widespread regression. From animals, along with specific grapetolites and brachopod pumps, wide development has reached intestinal - rhyme-forming corals. Tabulyts and rugosa, as well as crochet crumpled sinks and large, up to two meters long, sea arthropods Eurprises, cancerpions, giant-structures); The first fish and land plants appeared - psofields and plane.

Carbon (coal period) is highlighted by English geologists W. Konibir and W. Phillips in 1822, named by coal layers in the rocks of this period. After regression at the beginning of the carbon and extensive transgression, there was a sharp regression of the sea in its lower half, then the transgression of the sea came again. Along with brachyopods, corals, crosses, mollusks (especially champion, gonatifers and first whites), widespread developed by Foraminifera (large fuzulins), cartilage and bony fish (including sharks), Steodacephali, rectified insects (in particular, huge dragonflies). The first reptiles appeared, but they are still far away. Forests formed giant calaimis reeds, tree-like plauine lepidodendrons and sigillaria, gone cordates and fern; At the end of the period began the growth of conifers. In numerous swamps, peatlands were formed, then converted into the deposits of stone coal.

Perm was highlighted by R. Murchison in 4841, Naavana in the Perm province of Russia, where in an expedition organized by him with the participation of several Western European geologists studied the exposure of the breeds of this period (10 years earlier this period was allocated by the Belgian geologist O. D "Allua by section Saxony and Thuringia called Penenia, i.e. empty, imperative). It began intense regression of the sea, led at the end of the period to establish a long theocratic epoch, continued in Triassa. At the northern supercontinent of the laurels in the extensive lagunins of the arid subtropical zone, precipitation was deprived Evaporitis evaporation - Dolomites, anhydrites, gypsum, ka-menpaja and potash salt of Solikamsk and the German shop-matte, and in the wet equatorial zone they accumulated the masses of dead vegetation, which then turned into a coal departure of China. On the southern supercontinent of Gondwan, apparently in the South Supercontinent Poles, there was an extensive continental glaciation, traces of which in the rocks This period is available in Antarctica, Africa, India, Australia and South America. Fuzulins, brachiopods, sharks, sharkhalphs and animal reptile terromores flourished from animals (including huge predators of foresenters), they achieved flourishing and insects, but the trilobites and gonihitis almost disappeared.

Triass introduced F. Alberti in 1834, named its composition in continental sediments Western Europe Of the three layers: Mute sandstone, shell limestone and Caeper (three years earlier, was allocated: O. D "Al-Loua called Keyperian). The beginning of Triass was theocratic, then there was transgression, the formation of a number of edge seas on the periphery of the Pacific and, -Withmaking, the split gondwana into two parts: African-American and Indo-Australian. In Triassa, the marine and terrestrial fauna renewed. Wide development has reached ammonites, bivalve mollusks, six-storey corals, sea hedgehogs, ravenly developed reptiles, especially lash-time dinosaurs (terrible lizards); the first aquatic reptiles appeared - Pleiseiosaur and ichthyosaurs, as well as the first small mammals; by the end of the period, Steodacephali was finally extinct. In ground vegetation, gaming zealous cicades, ginkgo and coniferous were prevailing.

Yura is highlighted by the French geologist A. Bronary B 1829, named the Swiss-French Jurassic Mountains (in 1822, U. Konibir and W. Phillips were introduced under the name of the oolite system, while the name of Jurassic was offered at the same time A. Humboldt . The beginning of Yura was marked by the early phase of the Alpine Tecton-Magmatic Epoch, after which the transgression of the sea was followed (in particular, the Indian Ocean began to form), and at the end of the period, the next phase of alpine minion. Along, with sponges and rhyme-forming corals, bivalve, burglary and challenges (from the latter, the composition of ammonites was actively updated, whitewashed Belemnitis), marine hedgehogs, Liliy and Fish have developed broadcasts and plesiosaurs widely developed, gigantic forms of terrestrial vegetative and predatory dinosaurs, as well as flying lizards and toothy birds appeared. The rich was the fern, tail and gley vegetation.

Mel was allocated by O. D "Allua in 1822, named on the layers of white chalk, relating by age to the upper half of this period. For a small transgression at the beginning of the chalk and subsequent regression was followed by one of the deepest transgressions of Plyerozoic.

At this time, it seems that the South Atlantic was formed, and the end of the chalk was marked by a significant regression (with the formation of the Rocky Mountains of Oriental Andes). The sea dominated the Foraminifera (in particular, nummulites), the rhyme-forming colonies of bivalve mollusks of Rudists, ammonites with sinks of various and bizarre forms (sometimes huge, diameters up to 3 m), bone fish, large reptiles-ichthyosaurs (until the middle of the period), Plesiosaur, And in the upper chalk, the mesozavra is up to 12 m long. On land, reptiles prevailed, including the largest predators in the entire history of the Land of Tyrannozavra, large herbivorous iguanodones, large flying pheranodone lizards with a wings of the wings up to 8 m. At the end of the period, the first toothless birds appeared at the end of the period and placental mammals, and ammonites, whites, rudists, dinosaurs, plesiosaurs and many other animals extinct. From plants in the chalk period, ferns and gone prevailed in the chalk period, but even in the lower half of the chalk, covered bridges appeared, and in the second half they have already won domination.

The basis for recognizing various layers of marine sediments is bivalve mollusks of a plate of plastiphelter-beaded, bucheloga mollusks, foraminifera and indcode. In the world of terrestrial animals there was a number of new families and among their representatives - bears, dogs, hyenas, pebatic mastodonts and dinoteries, giant tigers, rhinos, antelopes, deer, sheep, first pigs, three-pall horses hipparones, man-like monkeys. The most diverse fauna was in Eurasia. In North America there were no mastodonts, deer and monkeys, predators were smaller, and hoofed more than in Eurasia; Migration of animals from Eurasia to North America began in the Late Miocene (apparently in the field of Chukotka - Alaska). In South America, specific short-term, hoofs, rodents, gigantic failures, flat monkeys developed; Migration of animals from North America to the South began only in average Pliocene. Australia with its specific silent remained isolated. Vegetation close to modern, testified of gradual cooling. At the end of Neogen, coniferous forests and even tundra appeared in the priarctic areas of the continents.

The Quaternary period was allocated by the French scientist J. Denuaye in 1829. The name is given as an addition to the "primary, secondary and tertiary" layers of rocks (by Arduino). The proper continental deposits were allocated by A. Werner called Alluvia in the 70s of the XVIII century. In 1823, an English scientist W. Buckland divided them to more ancient diluvium - the deployment of the "World Flood" - and more young Alluvius. In 1832, Ch. Lyleel called Diluvius Pleistocene, i.e. "the most new"; Later, he was also called the ice age, and post declared time - Holocene, i.e. "SAMEVOVY". Nonconecon, in 1922. The Russian geologist A. P. Pavlov proposed the name of Anthropogen for the Quaternary period to note the formation of a person and human society during this period.

The quarterly period is distinguished by repeated changes in climatic cooling and warming. In the high latitudes, continental glaciation arose in high latitudes (and in connection with the transition of significant amounts of water from the oceans, the level of risks dropped by 100-150 m - this is one of the types of global fluctuations in the sea level, in contrast to the regional caused by the vertical movements of the earth's crust, and from local oscillations); Outside the glacial regions, the wet climate was installed; There was a decrease in the temperature of the ocean surface water, even in the tropics it decreased by 6 ° C. During warming continental ice shields I installed, the ocean level was raised, the climate of the extlen private regions was becoming more dry. Climate fluctuations not only caused migration of animals and vegetation due to changes in their habitat, but also contributed to the emergence of some new species; So, for example, mammoths and wool rhinos appeared during the maximum (medium-orchetically) glaciation.

The commission on the international map of Quaternary sediments in Europe in 1932. It was customary to divide the Quaternary period to the lower, or Eoplestocene (ending with the end of the Mindelian glaciation of the Alps, about 300 thousand years ago), medium, or mesopleestos (ending with the end of the rice glaciation, about 75 thousand. Years ago), upper, or neo-love (ending with the end of the Würm wedge, documented by Sealing Salpauselyk in Southern Finland, 10.8-10.1 thousand years ago), and Golotocene. A more detailed dismemberment of the playpointly associated with the alternation of the phases of glands, we will consider in chapter 10 on the evolution of the climate.

Having completed on this brief description of the geological periods of phaperose, we will try to understand why geologists were dismembered by plywood just such, and not in any other way. The bases for one or another dismemberment are given by changes from the layer to the layer, firstly, the properties of sedimentary rocks (reflecting changes in the conditions of sedimentation in a particular region at appropriate periods of time, which, in turn, consequence, first of all previous horizontal and vertical movements of the earth's crust, i.e. its tectonics) and, secondly, the fossil residues of organisms (reflecting the level of development of life on Earth).

In the development of life, of course there was no periodicity, and paleontological data is no reason for the term "period" do not contain. Although the flourishing of certain periods of time (for example, we talked about the era of marine invertebrates, fish and amphibians - Paleozoa, the era of reptiles - Mesozoic, the era of mammals - Cenozoa, the age of trilobitis - Cambrian, the age of fish - Devon, about Ammonites Yura and Nummulitis Paleogen, associated mammoths with Pleistocene), but the boundaries of this heyday in most cases were blurred (for example, trilobites existed not only in Kebria, but also during the entire Paleozoic, and reptiles - not only in the Mesozoy, but also in Carbon, Some of them are thrive and now). Creating a good basis for recognition of layers of different ages, paleontological data, apparently, still do not give the unambiguous natural periodization of the history of phaperose.

Puerozoic Eon is part of geological time, originating about 542 million years ago and continuing to the present. Compared to the preceding (part of the geological history of the planet, including such aons, as,), plywood is famous for their abundance and worlds.

Era and periods

Plywood is divided into three eras, which in turn consist of periods:

Palaeozoic

Mesozoic era

Cenozoic era

Geography

During the plywood, the mainland drifted, and ultimately gathered into a single supercontinent, known as Pangea, and then divided into current parts of the world.

Some scientists believe that Puerozoic Eon began shortly after the collapse of the hypothetical supercontinent at the end of the global glacial period. During the early Paleozoic era there was a significant number of relatively small continents. By the end of the Paleozoa, the continents gathered together in Supercontinent Pangea, which included most of the earthly sushi.

The Mesozoic Epoch was characterized by a dramatic division of pangue: northern continent Laurelasia and South Continent Gondwan. By the end of the epoch, the continents almost acquired their current form. Laurela Stal North America and Eurasia, and Gondwan was divided into southern America, Africa, Australia, Antarctica and the Indian subcontinent.

The Cenozoic Era is a geological time interval, during which the continents occupied their current positions. Australia and New Guinea split from Gondwana. Antarctica is located above South Pole. Atlantic Ocean increased, and a little later South America Joined North America.

Climate

During Puerozoic Eon, the land climate varied between the conditions that supported global continental glaciation, and rather tropical, not having permanent ice hats even on the poles. The difference in global average temperatures between completely ice periods and rudely is estimated at about 10º C, although much greater changes were observed at high latitudes, and smaller on low latitudes.

The evolution of CO2 absorbing organisms in the Precambrian led to the creation of such an atmosphere, as today, although for most of the pilorozoic, it had a level of CO2 much higher than today. In the same way, the average temperature of the Earth was often higher than at present.

A life

The Paleozoic period did not have an atmosphere, as at present. When the amount of oxygen began to increase the ozone layer formed. At high altitude, the oxygen molecule is destroyed under the influence of ultraviolet radiation of the sun. These oxygen molecules are connected together to create ozone.

The thick layer of ozone exists at a height of 15 to 35 kilometers. This layer ensures that the harmful radiation of the Sun will not reach the surface of the Earth. The thicker the ozone layer, the less dangerous ultraviolet radiation falls on the ground. Before this protective function developed, the animals were primarily used. Consequently, Flora and Fauna Puerozoos were able to colonize land. Early plants grew on land in the silver (about 430 million years ago). These were vascular plants, such as ferns. Several species arose very quickly.

Devon appeared, and reptiles - in the coal period. At the border of Triass and Yura (200 million years ago), mammals appeared for the first time and, finally, birds. Mammals have become dominant animals after the disappearance of dinosaurs at the sunset of the Cretaceous period (66 million years ago).