All eras and periods are table. Era of the earth

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

The table of the development of life on Earth can be compiled based on the chronology of events. The entire history of the Earth can be divided into certain stages. The largest of them are the eras of life. They are divided into eras, eras - into periods, periods - into eras, epochs - into centuries.

Eras of life on Earth

The entire period of existence of life on Earth can be divided into 2 periods: Precambrian, or cryptose (primary period, 3.6 to 0.6 billion years), and Phanerozoic.

Cryptozoic includes the Archean (ancient life) and Proterozoic (primary life) eras.

The Phanerozoic includes the Paleozoic (ancient life), Mesozoic (middle life), and Cenozoic (new life) eras.

These 2 periods of the development of life are usually divided into smaller ones - eras. The boundaries between eras are global evolutionary events, extinctions. In turn, eras are divided into periods, periods - into eras. The history of the development of life on Earth is directly related to changes in the earth's crust and the planet's climate.

Eras of development, countdown

It is customary to allocate the most significant events at special time intervals - eras. Time is counted in reverse order, from the oldest life to the new. There are 5 eras:

Periods of development of life on Earth

The Paleozoic, Mesozoic and Cenozoic eras include periods of development. These are shorter periods of time compared to eras.

• Cambrian (Cambrian).
• Ordovician.
• Silurian (Silurian).
• Devonian (Devonian).
• Carboniferous (carbonaceous).
• Perm (Perm).

• Lower Tertiary (Paleogene).
• Upper Tertiary (Neogene).
• Quaternary, or anthropogen (human development).

The first 2 periods are included in the Tertiary period with a duration of 59 million years.

Proterozoic era (early life)

6. Perm (Perm)

2. Upper Tertiary (Neogene)

3. Quaternary or anthropogen (human development)

Development of living organisms

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

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

• Mesozoic era.

• Triassic. Distribution of plants (gymnosperms). An increase in the number of reptiles. The first mammals, bony fish.
• Jurassic period. The predominance of gymnosperms, the emergence of angiosperms. The appearance of the first bird, the flowering of cephalopods.
• Cretaceous period. Distribution of angiosperms, reduction of other plant species. Development of bony fish, mammals and birds.

• Cenozoic era.
  • Lower Tertiary (Paleogene). The flowering of angiosperms. The development of insects and mammals, the appearance of lemurs, later primates.
  • Upper Tertiary (Neogene). Formation of modern plants. The appearance of the ancestors of people.
  • Quaternary period (anthropogen). Formation of modern plants, animals. The emergence of man.

Development of inanimate conditions, climate change

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

Climate change: the Archean era

The history of the development of life on Earth began through the stage of the predominance of land over water resources. The relief was poorly lined. The atmosphere is dominated by carbon dioxide, the amount of oxygen is minimal. Low salinity in shallow water.

The Archean era is characterized by volcanic eruptions, lightning, black clouds. The rocks are rich in graphite.

Climatic changes in the Proterozoic era

Land is a stone desert, all living organisms live in water. Oxygen accumulates in the atmosphere.

Climate Change: Paleozoic Era

During different periods of the Paleozoic era, the following climate changes took place:

• Cambrian period. The land is still deserted. The climate is hot.
• Ordovician period. The most significant changes are the flooding of almost all northern platforms.
• Silurian. Tectonic changes, conditions of inanimate nature are diverse. Mountain building takes place, seas prevail over land. Areas of different climates, including regions of cooling, have been determined.
• Devonian. The climate is dry and continental. Formation of intermontane depressions.
• Carboniferous period. Subsidence of continents, wetlands. Warm and humid climate, the atmosphere is rich in oxygen and carbon dioxide.
• Permian period. Hot climate, volcanic activity, mountain building, drying up of swamps.

In the Paleozoic era, mountains of the Caledonian folding were formed. Such changes in topography affected the world's oceans - sea basins have shrunk, and a significant land area has been formed.

The Paleozoic era marked the beginning of almost all major oil and coal deposits.

Climatic changes in the Mesozoic

The climate of different periods of the Mesozoic is characterized by the following features:

• Triassic. Volcanic activity, the climate is sharply continental, warm.
• Jurassic period. Mild and warm climate. Seas prevail over land.
• Cretaceous period. Retreat of the seas from land. The climate is warm, but at the end of the period, global warming is replaced by a cold snap.

In the Mesozoic era, the previously formed mountain systems are destroyed, the plains go under water (Western Siberia). In the second half of the era, the Cordillera, the mountains of Eastern Siberia, Indochina, partly Tibet were formed, the mountains of the Mesozoic folding were formed. A hot and humid climate prevails, favoring the formation of swamps and peat bogs.

Climate Change - Cenozoic Era

In the Cenozoic era, there was a general uplift of the Earth's surface. The climate has changed. Numerous glaciations of the earth's covers advancing from the north have changed the appearance of the continents of the Northern Hemisphere. Thanks to these changes, hilly plains were formed.

• Lower Tertiary period. Mild climate. Division into 3 climatic zones. Formation of continents.
• Upper Tertiary period. Dry climate. The emergence of steppes, savannas.
• Quaternary period. Multiple glaciation of the northern hemisphere. Cooling climate.

All changes during the development of life on Earth can be written in the form of a table that will reflect the most significant stages in the formation and development of the modern world. Despite the already known research methods, and now scientists continue to study history, make new discoveries that allow modern society to learn how life developed on Earth before the appearance of man.

Development of life on Earth lasts over 3 billion years. And this process continues to this day.

The first living things in the Archean were bacteria. Then came unicellular algae, animals and fungi. Unicellular organisms have been replaced by multicellular organisms. At the beginning of the Paleozoic, life was already very diverse: representatives of all types of invertebrates lived in the seas, and the first land plants appeared on land. In the following eras, various groups of plants and animals formed and died out over many millions of years. Gradually, the living world became more and more similar to the modern one.

2.6. The history of the development of life

Previously, scientists believed that the living came from the living. Bacterial spores were brought in from space. Some bacteria created organic matter, others consumed and destroyed them. As a result, the most ancient ecosystem arose, the components of which were linked by the cycle of substances.

Modern scientists have proven that living things came from non-living nature. In the aquatic environment, organic substances were formed from inorganic substances under the influence of the energy of the Sun and the internal energy of the Earth. The most ancient organisms - bacteria were formed from them.

In the history of the development of life on Earth, several eras are distinguished.

Archaea

The first organisms were prokaryotes. In the Archean era, a biosphere already existed, consisting mainly of prokaryotes. The very first living things on the planet are bacteria. Some of them were capable of photosynthesis. Photosynthesis was carried out by cyanobacteria (blue-green).

Proterozoic

As the oxygen content in the atmosphere increased, eukaryotic organisms began to appear. In the Proterozoic, unicellular plants arose in the aquatic environment, and then unicellular animals and fungi. The emergence of multicellular organisms was an important event in the Proterozoic. By the end of the Proterozoic, various types of invertebrates and chordates had already appeared.

Paleozoic

Plants

Gradually, land appeared in place of the warm shallow seas. As a result, the first land plants originated from multicellular green algae. In the second half of the Paleozoic, forests arose. They consisted of ancient ferns, horsetails, and lyre, which multiplied by spores.

Animals

In the early Paleozoic, marine invertebrates flourished. In the seas, vertebrates, shell fish, developed and spread.

In the Paleozoic, the first terrestrial vertebrates appeared - the oldest amphibians. From them, at the end of the era, the first reptiles descended.

The most numerous in the seas of the Paleozoic (the era of ancient life) were trilobites - fossil arthropods, outwardly similar to giant woodlice. Trilobites - existed at the beginning of the Paleozoic, completely extinct 200 million years ago. They swam and crawled in shallow bays, feeding on plants and animal remains. There is an assumption that there were also predators among the trilobites.

Arachnids and giant flying insects, the ancestors of modern dragonflies, were the very first among animals to master the land. Their wingspan reached 1.5 m.

Mesozoic

In the Mesozoic, the climate became more arid. Ancient forests gradually disappeared. Spore-bearing plants were replaced by seed-propagating plants. Among animals, reptiles, including dinosaurs, flourished. At the end of the Mesozoic, many species of ancient seed plants and dinosaurs became extinct.

Animals

The largest of the dinosaurs were the brachiosaurs. They reached over 30 m in length and weighed 50 tons. These dinosaurs had a huge body, long tail and neck, and a small head. If they lived in our time, they would be higher than five-story buildings.

Plants

The most complex plants are flowering plants. They appeared in the middle of the Mesozoic (the era of middle life). Material from the site http://wikiwhat.ru

Cenozoic

Cenozoic - the heyday of birds, mammals, insects and flowering plants. Warm-bloodedness arose in birds and mammals due to the more perfect structure of organ systems. They have become less dependent on environmental conditions and have spread widely on Earth.

Geological chronology, or geochronology, is based on elucidating the geological history of the most well-studied regions, for example, in Central and Eastern Europe. On the basis of broad generalizations, a comparison of the geological history of various regions of the Earth, the laws of the evolution of the organic world at the end of the last century, at the first International Geological Congresses, the International Geochronological Scale was developed and adopted, reflecting the sequence of time divisions during which certain complexes of deposits were formed, and the evolution of the organic world ... Thus, the international geochronological scale is a natural periodization of the history of the Earth.

Among the geochronological subdivisions stand out: eon, era, period, epoch, century, time. Each geochronological subdivision corresponds to a complex of deposits, distinguished in accordance with the change in the organic world and called stratigraphic: eonoteme, group, system, department, stage, zone. Consequently, a group is a stratigraphic unit, and the corresponding temporal geochronological unit represents an 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 are dealing with sediments, since some geological events took place in every place of the globe at any time. Another thing is that the accumulation of precipitation was not ubiquitous.

• The Archean and Proterozoic eonothems, covering almost 80% of the Earth's existence, are distinguished in cryptose, since the skeletal fauna is completely absent in the Precambrian formations and the paleontological method is not applicable to their dissection. Therefore, the division of the Precambrian formations is based primarily on general geological and radiometric data.
• The Phanerozoic eon covers only 570 Ma and the dissection of the corresponding eonothem of deposits is based on a wide variety of numerous skeletal fauna. The Phanerozoic eonothem is subdivided into three groups: Paleozoic, Mesozoic and Cenozoic, corresponding to major stages of the natural geological history of the Earth, the boundaries of which are marked by rather sharp changes in the organic world.

The names of eonothems and groups come from the Greek words:

• "archeos" - the most ancient, the most ancient;
• "proteros" - primary;
• "paleos" - ancient;
• "mezos" - medium;
• "kainos" is new.

The word "kryptos" means hidden, and "phanerozoic" means explicit, transparent, since the skeletal fauna appeared.
The word "zoi" comes from "zoikos" - vital. Therefore, the "Cenozoic era" means the era of new life, and so on.

Groups are subdivided into systems, the deposits of which were formed during one period and are characterized only by their inherent families or genera of organisms, and if they are plants, then by genera and species. Systems have been identified in different regions and at different times, starting in 1822. Currently, 12 systems are distinguished, the names of most of which come from the places where they were first described. For example, the Jurassic system - from the Jurassic mountains in Switzerland, the Permian - from the Perm province in Russia, the Cretaceous - according to the most characteristic rocks - white writing chalk, etc. The Quaternary system is often called anthropogenic, since it is in this age interval that a person appears.

The systems are subdivided into two or three sections, which correspond to the early, middle, and late eras. The departments, in turn, are divided into tiers, which are characterized by the presence of certain genera and species of fossil fauna. And finally, the stages are subdivided into zones that are the most fractional part of the international stratigraphic scale, which corresponds to time in the geochronological scale. The names of the tiers are usually given according to the geographical names of the regions where this tier was identified; for example, the Aldanian, Bashkirian, Maastrichtian stages, etc. At the same time, the zone is designated by the most characteristic type of fossil fauna. The zone, as a rule, covers only a certain part of the region and is developed on a smaller area than the deposits of the stage.

All subdivisions of the stratigraphic scale correspond to the geological sections in which these subdivisions were first identified. Therefore, such sections are standard, typical and are called stratotypes, which contain only their characteristic complex of organic remains, which determines the stratigraphic volume of a given stratotype. Determination of the relative age of any layers consists in comparing the discovered complex of organic remains in the studied layers with the complex of fossils in the stratotype of the corresponding subdivision of the international geochronological scale, i.e. the age of the deposits is determined relative to the stratotype. That is why the paleontological method, despite its inherent shortcomings, remains the most important method for determining the geological age of rocks. Determination of the relative age, for example, of the Devonian deposits, indicates only that these deposits are younger than the Silurian, but older than the Carboniferous. However, it is impossible to establish the duration of the formation of Devonian deposits and to give a conclusion about when (in absolute chronology) the accumulation of these deposits took place. Only the methods of absolute geochronology are able to answer this question.

Tab. 1. Geochronological table

Era	Period	Epoch	Duration, million years	Time from the beginning of the period to the present day, million years	Geological conditions	Vegetable world	Animal world
Cenozoic (mammalian time)	Quaternary	Modern	0,011	0,011	End of the last ice age. The climate is warm	Decline of woody forms, flowering of herbaceous	Age of man
		Pleistocene	1	1	Repeated glaciations. Four ice ages	Extinction of many plant species	Extinction of large mammals. The origin of human society
	Tertiary	Pliocene	12	13	The mountains continue to rise in western North America. Volcanic activity	Decline of forests. Distribution of meadows. Flowering plants; development of monocots	The emergence of man from great apes. Types of elephants, horses, camels, similar to modern
		Miocene	13	25	The Sierras and the Cascade Mountains were formed. Volcanic activity in the northwestern United States. The climate is cool		The culmination period in the evolution of mammals. The first great apes
		Oligocene	11	30	The continents are low-lying. The climate is warm	Maximum distribution of forests. Strengthening the development of monocotyledonous flowering plants	Archaic mammals are dying out. The beginning of the development of anthropoids; predecessors of most living mammalian genera
		Eocene	22	58	The mountains are blurred. There are no inland seas. The climate is warm		Diverse and specialized placental mammals. Ungulates and predators reach their prime
		Paleocene	5	63			Distribution of archaic mammals
Alpine mountain building (minor fossil destruction)
Mesozoic (reptile time)	a piece of chalk		72	135	At the end of the period, the Andes, Alps, Himalayas, Rocky Mountains are formed. Prior to that, inland seas and swamps. Deposition of writing chalk, shale	The first monocots. The first oak and maple forests. Decline of gymnosperms	Dinosaurs reach their highest development and die out. Toothed birds are dying out. The appearance of the first modern birds. Archaic mammals are common
	Yura		46	181	The continents are quite elevated. Shallow seas cover parts of Europe and the western United States	The value of dicotyledons is increasing. Cycadophytes and conifers are common	The first toothed birds. Dinosaurs are large and specialized. Insectivorous marsupials
	Triassic		49	230	The continents are elevated above sea level. Intensive development of arid climate conditions. Widespread continental sediments	The dominance of gymnosperms, already beginning to decline. Seed fern extinction	The first dinosaurs, pterosaurs and oviparous mammals. Extinction of primitive amphibians
Hercynian orogeny (some fossil destruction)
Paleozoic (era of ancient life)	Permian		50	280	The continents are uplifted. The Appalachian Mountains were formed. Aridity is increasing. Glaciation in the southern hemisphere	Decline of lymphoids and fern-like plants	Many ancient animals are dying out. Animal-like reptiles and insects develop
	Upper and middle carbon		40	320	The continents are low-lying at first. Extensive swamps where coal has formed	Large forests of seed ferns and gymnosperms	The first reptiles. Insects are common. Distribution of ancient amphibians
	Lower Carboniferous		25	345	The climate is initially warm and humid, later, due to the rise of land, it is cooler.	Plaunas and fern-like plants dominate. Gymnosperms are spreading more and more	Sea lilies reach their highest development. Distribution of ancient sharks
	Devonian		60	405	Small inland seas. Raising land; development of arid climate. Glaciation	The first forests. Land plants are well developed. The first gymnosperms	The first amphibians. Abundance of lungfish and sharks
	Silurian		20	425	Vast inland seas. Lowlands become increasingly arid as land rises	The first reliable traces of land plants. Algae dominate	Marine arachnids dominate. The first (wingless) insects. The development of fish is enhanced
	Ordovician		75	500	Significant sushi immersion. The climate is warm, even in the Arctic	Probably the first terrestrial plants appear. Abundance of seaweed	The first fish are probably freshwater. Abundance of corals and trilobites. Various molluscs
	Cambrian		100	600	The continents are low-lying, the climate is temperate. The oldest rocks with abundant fossils	Seaweed	Trilobites and non-legged dominate. The origin of most modern animal types
Second Great Mountain Building (Significant Fossil Destruction)
Proterozoic			1000	1600	Intense sedimentation process. Later - volcanic activity. Erosion over large areas. Multiple glaciations	Primitive aquatic plants - algae, fungi	Various marine protozoa. By the end of the era - molluscs, worms and other marine invertebrates
First great mountain building (significant fossil destruction)
Archaea			2000	3600	Significant volcanic activity. Weak process of sedimentation. Erosion over large areas	There are no fossils. Indirect indications of the existence of living organisms in the form of deposits of organic matter in rocks

The problem of determining the absolute age of rocks, the duration of the existence of the Earth has long occupied the minds of geologists, and attempts to solve it have been made many times, for which various phenomena and processes were used. Early ideas about the absolute age of the Earth were curious. A contemporary of MV Lomonosov, the French naturalist Buffon, determined the age of our planet at only 74,800 years. Other scientists gave different 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 rates of processes, which, as is known, changed in the geological history of the Earth. And only in the first half of the XX century. a real opportunity has appeared to measure the truly absolute age of rocks, geological processes and the Earth as a planet.

Tab. 2. Isotopes used to determine absolute age
Parent isotope	Final product	Half-life, billion years
147 Sm	143 Nd + He	106
238 U	206 Pb + 8 He	4,46
235 U	208 Pb + 7 He	0,70
232 Th	208 Pb + 6 He	14,00
87 Rb	87 Sr + β	48,80
40 K	40 Ar + 40 Ca	1,30
14 C	14 N	5730 years

In the beginning there was nothing. In the endless outer space, there was only a giant cloud of dust and gases. It can be assumed that from time to time, space ships with representatives of the universal mind rushed through this substance at great speed. The humanoids looked bored through the windows and did not even remotely suspect that in a few billion years, intelligence and life would arise in these places.

Over time, the gas and dust cloud transformed into the solar system. And after the star arose, the planets appeared. Our native land became one of them. It happened 4.5 billion years ago. It is from those distant times that the age of the blue planet has been counted, thanks to which we exist in this world.

Stages of development of the Earth

The entire history of the Earth is divided into two huge stages in time.... The first stage is characterized by the absence of complex living organisms. There were only unicellular bacteria that settled on our planet about 3.5 billion years ago. The second stage began about 540 million years ago. This is the time when living multicellular organisms spread across the Earth. This refers to both plants and animals. Moreover, both the sea and the land became their habitat. The second period continues to this day, and its crown is a man.

Such huge time stages are called eons... Each eon has its own eonotema... The latter represents a certain stage in the geological development of the planet, which is fundamentally different from other stages in the lithosphere, hydrosphere, atmosphere, biosphere. That is, each eonoteme is strictly specific and not like the others.

There are 4 eons in total. Each of them, in turn, is subdivided into eras of the Earth, and those are subdivided into periods. From this it can be seen that there is a rigid gradation of large time intervals, and the geological development of the planet is taken as a basis.

Katarchei

The most ancient aeon is called Katarchea. It began 4.6 billion years ago and ended 4 billion years ago. Thus, its duration was 600 million years. Time is very ancient, so it was not divided into either eras or periods. At the time of the Katarchean, there was neither the earth's crust nor the nucleus. The planet was a cold space body. The temperature in its interior corresponded to the melting point of the substance. From above, the surface was covered with regolith, as in our time lunar. The relief was almost flat due to constant powerful earthquakes. Naturally, there was no atmosphere or oxygen.

Archaea

The second aeon is called Archean. It began 4 billion years ago and ended 2.5 billion years ago. Thus, it lasted 1.5 billion years. It is subdivided into 4 eras: Eoarchean, Paleoarchean, Mesoarchean and Neoarchean.

Eoarcheus(4-3.6 billion years) lasted 400 million years. This is the period of the formation of the earth's crust. A huge number of meteorites fell on the planet. This is the so-called Late Heavy Bombardment. It was at that time that the formation of the hydrosphere began. Water appeared on Earth. A large number of it could be brought in by comets. But the oceans were still far away. There were separate reservoirs, and the temperature in them reached 90 ° Celsius. The atmosphere was high in carbon dioxide and low in nitrogen. There was no oxygen. At the end of the era, the first supercontinent, Vaalbara, began to form.

Paleoarchean(3.6-3.2 billion years) lasted 400 million years. In this era, the formation of the solid core of the Earth was completed. A strong magnetic field has appeared. His tension was half of the current one. Consequently, the planet's surface received protection from the solar wind. This period also includes primitive forms of life in the form of bacteria. Their remains, which are 3.46 billion years old, were discovered in Australia. Accordingly, the oxygen content in the atmosphere began to increase, due to the activity of living organisms. The formation of Vaalbar continued.

Mesoarchean(3.2-2.8 billion years) lasted 400 million years. The most remarkable thing about it was the existence of cyanobacteria. They are capable of photosynthesis and release oxygen. Completed the formation of the supercontinent. By the end of the era, it split. A huge asteroid also fell. The crater from it still exists in Greenland.

Neoarchean(2.8-2.5 billion years) lasted 300 million years. This is the time of the formation of the real earth's crust - tectogenesis. Bacteria continued to develop. Traces of their life have been found in stromatolites, the age of which is estimated at 2.7 billion years. These limescale deposits were formed by huge colonies of bacteria. They were found in Australia and South Africa. Photosynthesis continued to improve.

With the end of the Archean era, the Earths received their continuation in the Proterozoic eon. This is a period of 2.5 billion years - 540 million years ago. It is the longest of all the eons of the planet.

Proterozoic

The Proterozoic is divided into 3 eras. The first is called paleoproterozoic(2.5-1.6 billion years). It lasted 900 million years. This huge time interval is subdivided into 4 periods: sideria (2.5-2.3 billion years), riasium (2.3-2.05 billion years), orosirium (2.05-1.8 billion years) , staterium (1.8-1.6 billion years).

Siderius remarkable first of all oxygen disaster... It happened 2.4 billion years ago. It is characterized by a radical change in the Earth's atmosphere. Free oxygen appeared in it in huge quantities. Before that, the atmosphere was dominated by carbon dioxide, hydrogen sulfide, methane and ammonia. But as a result of photosynthesis and the extinction of volcanic activity at the bottom of the oceans, oxygen filled the entire atmosphere.

Oxygen photosynthesis is characteristic of cyanobacteria, which proliferated on Earth 2.7 billion years ago. Before that, archaebacteria prevailed. They did not produce oxygen during photosynthesis. In addition, oxygen was initially consumed for the oxidation of rocks. In large quantities, it accumulated only in biocenoses or bacterial mats.

Eventually, the moment came when the surface of the planet turned out to be oxidized. And the cyanobacteria continued to release oxygen. And it began to accumulate in the atmosphere. The process has accelerated due to the fact that the oceans also stopped absorbing this gas.

As a result, anaerobic organisms died, and they were replaced by aerobic ones, that is, those in which the synthesis of energy was carried out through free molecular oxygen. The planet was enveloped in the ozone layer and the greenhouse effect decreased. Accordingly, the boundaries of the biosphere expanded, and sedimentary and metamorphic rocks were completely oxidized.

All these metamorphoses led to Huron glaciation, which lasted 300 million years. It began in sideria and ended at the end of riasia 2 billion years ago. The next period of the Orosirians is notable for its intensive mountain building processes. At this time, 2 huge asteroids fell on the planet. A crater from one is called Vredefort and is located in South Africa. Its diameter reaches 300 km. Second crater Sudbury located in Canada. Its diameter is 250 km.

Last staterian period notable for the formation of the supercontinent Colombia. It includes almost all continental blocks of the planet. There was a supercontinent 1.8-1.5 billion years ago. At the same time, cells were formed that contained nuclei. That is, eukaryotic cells. This was a very important stage in evolution.

The second era of the Proterozoic is called mesoproterozoic(1.6-1 billion years). Its duration was 600 million years. It is divided into 3 periods: potassium (1.6-1.4 billion years), exathium (1.4-1.2 billion years), stheny (1.2-1 billion years).

The supercontinent Columbia disintegrated during the Kalimium era. And at the time of exation, red multicellular algae appeared. This is indicated by a fossil find on the Canadian island of Somerset. Its age is 1.2 billion years. A new supercontinent, Rodinia, was formed in Stania. It arose 1.1 billion years ago, and disintegrated 750 million years ago. Thus, by the end of the Mesoproterozoic, there was 1 supercontinent and 1 ocean on Earth, called Mirovia.

The last era of the Proterozoic is called neoproterozoic(1 billion - 540 million years). It includes 3 periods: Tony (1 billion-850 million years), cryogeny (850-635 million years), Ediacaria (635-540 million years).

During the time of Tony, the disintegration of the supercontinent Rodinia began. This process ended in cryogeny, and the supercontinent Pannotia began to form from 8 separate pieces of land formed. Cryogeny is also characterized by complete glaciation of the planet (Earth-snowball). The ice reached the equator, and after they retreated, the process of evolution of multicellular organisms sharply accelerated. The last period of the Neoproterozoic Ediacaran is notable for the appearance of soft-bodied creatures. These multicellular animals are named Vendobionts... They represented branching tubular structures. This ecosystem is considered to be the oldest.

Life on Earth originated in the ocean

Phanerozoic

Approximately 540 million years ago, the time of the 4th and last eon, the Phanerozoic, began. There are 3 very important eras of the Earth here. The first is called Paleozoic(540-252 million years). It lasted 288 million years. It is divided into 6 periods: Cambrian (540-480 Ma), Ordovician (485-443 Ma), Silurian (443-419 Ma), Devonian (419-350 Ma), Carboniferous (359-299 million years) and Permian (299-252 million years).

Cambrian is considered the lifetime of trilobites. These are marine animals similar to crustaceans. Together with them, jellyfish, sponges and worms lived in the seas. Such an abundance of living beings is called Cambrian explosion... That is, before that, there was nothing like this and suddenly appeared abruptly. Most likely, it was in the Cambrian that mineral skeletons began to emerge. Earlier, the living world had soft bodies. Naturally, they have not survived. Therefore, complex multicellular organisms of more ancient eras cannot be detected.

The Paleozoic is notable for the rapid dispersal of organisms with rigid skeletons. From vertebrates appeared fish, reptiles and amphibians. In the plant world, algae predominated at first. During silurian plants began to master the land. At the beginning devonian swampy shores are overgrown with primitive flora. They were psilophytes and pteridophytes. Plants propagated by spores that were carried by the wind. Plant shoots developed on tuberous or creeping rhizomes.

Plants began to master the land in the Silurian period

Scorpions and spiders appeared. The real giant was the meganeura dragonfly. Its wingspan reached 75 cm. Acanthodes are considered the most ancient bony fish. They lived during the Silurian period. Their bodies were covered with dense diamond-shaped scales. IN carbon, which is also called the Carboniferous period, on the shores of lagoons and in countless swamps, the most diverse vegetation developed rapidly. It was its remains that served as the basis for the formation of coal.

This time is also characterized by the beginning of the formation of the Pangea supercontinent. It was fully formed in the Permian period. And it broke up 200 million years ago into 2 continents. These are the northern continent of Laurasia and the southern continent of Gondwana. Subsequently, Laurasia split, and Eurasia and North America were formed. And from Gondwana originated South America, Africa, Australia and Antarctica.

On the Permian there were frequent climate changes. Dry times gave way to wet ones. At this time, lush vegetation appeared on the banks. Typical plants were kordaites, calamites, tree and seed ferns. Mesosaurus lizards appeared in the water. Their length reached 70 cm. But by the end of the Permian period, the early reptiles became extinct and gave way to more developed vertebrates. Thus, in the Paleozoic, life reliably and densely settled on the blue planet.

The following eras of the Earth are of particular interest to scientists. 252 million years ago came Mesozoic... It lasted 186 million years and ended 66 million years ago. It consisted of 3 periods: Triassic (252-201 Ma), Jurassic (201-145 Ma), Cretaceous (145-66 Ma).

The boundary between the Permian and Triassic periods is characterized by the mass extinction of animals. Killed 96% of marine species and 70% of terrestrial vertebrates. The biosphere was dealt a very strong blow, and it took a very long time to recover. And it all ended with the appearance of dinosaurs, pterosaurs and ichthyosaurs. These sea and land animals were enormous in size.

But the main tectonic event of those years was the collapse of Pangea. A single supercontinent, as already mentioned, divided into 2 continents, and then disintegrated into those continents that we know now. The Indian subcontinent also broke away. Subsequently, it merged with the Asian plate, but the collision was so violent that the Himalayas arose.

This nature was in the early Cretaceous period

The Mesozoic is notable for what is considered the warmest period of the Phanerozoic eon.... This is the time of global warming. It began in the Triassic and ended at the end of the Cretaceous. For 180 million years even in the Arctic there were no stable pack glaciers. Heat spread evenly over the planet. At the equator, the average annual temperature was 25-30 ° Celsius. The subpolar regions were characterized by a moderately cool climate. In the first half of the Mesozoic, the climate was dry, while the second half was characterized by a humid one. It was at this time that the equatorial climatic zone was formed.

In the animal kingdom, mammals arose from the subclass of reptiles. This was due to the improvement of the nervous system and the brain. The limbs moved from the sides under the body, the reproductive organs became more perfect. They ensured the development of the embryo in the mother's body, followed by feeding it with milk. A fur coat appeared, blood circulation and metabolism improved. The first mammals appeared in the Triassic, but they could not compete with dinosaurs. Therefore, for more than 100 million years, they occupied a dominant position in the ecosystem.

The last era is considered cenozoic(beginning 66 million years ago). This is the current geological period. That is, we all live in the Cenozoic. It is subdivided into 3 periods: Paleogene (66-23 million years), Neogene (23-2.6 million years) and the modern Anthropogen or Quaternary period, which began 2.6 million years ago.

There are 2 main events in the Cenozoic... Mass extinction of dinosaurs 65 million years ago and a general cooling on the planet. The death of animals is associated with the fall of a huge asteroid with a high content of iridium. The diameter of the cosmic body reached 10 km. As a result, a crater was formed Chicxulub with a diameter of 180 km. It is located on the Yucatan Peninsula in Central America.

Surface of the Earth 65 million years ago

After the fall, an explosion of enormous power occurred. Dust rose into the atmosphere and blocked the planet from the sun's rays. The average temperature dropped by 15 °. The dust hung in the air for a whole year, which led to a sharp cold snap. And since the Earth was inhabited by large heat-loving animals, they became extinct. Only small representatives of the fauna remained. It was they who became the ancestors of the modern animal world. This theory is based on iridium. The age of its layer in geological deposits corresponds exactly to 65 million years.

During the Cenozoic, the continents diverged. Each of them formed its own unique flora and fauna. The variety of marine, flying and land animals has increased significantly in comparison with the Paleozoic. They became much more sophisticated, and mammals took the dominant position on the planet. Higher angiosperms appeared in the plant kingdom. This is the presence of a flower and ovule. Cereals also appeared.

The most important in the last era is anthropogen or quaternary period, which began 2.6 million years ago. It consists of 2 eras: the Pleistocene (2.6 million years - 11.7 thousand years) and the Holocene (11.7 thousand years - our time). During the Pleistocene era mammoths, cave lions and bears, marsupial lions, saber-toothed cats and many other species of animals that became extinct at the end of the era lived on Earth. A man appeared on the blue planet 300 thousand years ago. It is believed that the first Cro-Magnons chose the eastern regions of Africa for themselves. At the same time, Neanderthals lived on the Iberian Peninsula.

Notable for the Pleistocene and ice ages... For 2 million years, very cold and warm periods of time alternated on Earth. Over the past 800 thousand years, there have been 8 ice ages with an average duration of 40 thousand years. In cold times, glaciers advanced on the continents, and retreated in the interglacial period. At the same time, the level of the World Ocean increased. About 12 thousand years ago, already in the Holocene, the next ice age ended. The climate became warm and humid. Thanks to this, humanity has settled throughout the planet.

Holocene is an interglacial... It has been going on for 12 thousand years. For the last 7 thousand years, human civilization has been developing. The world has changed in many ways. The flora and fauna have undergone significant transformations due to human activity. Nowadays, many species of animals are on the verge of extinction. Man has long considered himself the ruler of the world, but the eras of the Earth have not gone anywhere. Time continues its steady pace, and the blue planet conscientiously revolves around the Sun. In a word, life goes on, but what will happen next - the future will show.

The article was written by Vitaly Shipunov

Hey! In this article I want to tell you about the geochronological column. This is a column of the periods of the Earth's development. And also in more detail about each era, thanks to which you can draw a picture of the formation of the Earth throughout its history. What kinds of life first appeared, how they changed, and how much it took.

The geological history of the Earth is divided into large intervals - eras, eras are divided into periods, periods are divided into eras. This division was associated with the events that took place on. The change in the abiotic environment influenced the evolution of the organic world on Earth.

Geological eras of the Earth, or geochronological scale:

And now about everything in more detail:

Legend:
Era;
Periods;
Epochs.

1. Katarchean era (from the creation of the Earth, about 5 billion years ago, to the origin of life);

2. Archean era , the most ancient era (3.5 billion - 1.9 billion years ago);

3. Proterozoic era (1.9 billion - 570 million years ago);

Archean and Proterozoic are still united in the Precambrian. The Precambrian covers most of the geological time. Formed, areas of land and sea, there was an active volcanic activity. Shields of all continents were formed from Precambrian rocks. Traces of life are usually rare.

4. Palaeozoic (570 million - 225 million years ago) with such periods :

Cambrian period(from the Latin name for Wales)(570 million - 480 million years ago);

The transition to the Cambrian was marked by the unexpected appearance of a huge amount of fossils. This is a sign of the beginning of the Paleozoic era. In the many shallow seas, marine life flourished. Trilobites were especially widespread.

Ordovician period(from the British Ordovician tribe)(480 million - 420 million years ago);

A large part of the Earth was soft, most of the surface was still covered by seas. The accumulation of sedimentary rocks continued, mountain building took place. There were reef-forming ones. There is an abundance of corals, sponges and molluscs.

Silurian (from the British Silurian tribe)(420 million - 400 million years ago);

Dramatic events in the history of the Earth began with the development of the jawless fish-like (the first vertebrates) that appeared in the Ordovician. Another significant event was the appearance of the first terrestrial ones in the late Silurian.

Devonian (from Devonshire in England)(400 million - 320 million years ago);

In the early Devonian, mountain-building movements reached their peak, but this was mainly a period of spasmodic development. The first seed plants settled on land. A great variety and number of fish-like species were noted, the first terrestrial animals- amphibians.

Carboniferous or Carboniferous period (from the abundance of coal in the seams) (320 million - 270 million years ago);

Mountain building, folding, erosion continued. In North America, swampy forests and river deltas were inundated, and large coal deposits were formed. The southern continents were covered by glaciation. Insects spread rapidly, and the first reptiles appeared.

Permian period (from the Russian city of Perm)(270 million - 225 million years ago);

In much of Pangea, the supercontinent that united all, conditions reigned supreme. Reptiles spread widely, and modern insects evolved. New terrestrial flora developed, including conifers. Several marine species have disappeared.

5. Mesozoic era (225 million - 70 million years ago) with such periods:

Triassic (from the three-part division of the period proposed in Germany)(225 million - 185 million years ago);

With the onset of the Mesozoic era, Pangea began to disintegrate. The dominance of conifers was established on land. Diversity among reptiles was noted, with the first dinosaurs and giant marine reptiles emerging. Primitive mammals developed.

Jurassic period(from mountains in Europe)(185 million - 140 million years ago);

Significant volcanic activity has been associated with the formation of the Atlantic Ocean. On land, dinosaurs dominated, the air ocean was conquered by flying reptiles and primitive birds. There are traces of the first flowering plants.

Cretaceous period (from the word "chalk")(140 million - 70 million years ago);

During the maximum expansion of the seas, chalk deposits occurred, especially in Britain. The dominance of the dinosaurs continued until the extinction of them and other species at the end of the period.

6. Cenozoic era (70 million years ago - to our time) with such periods and eras:

Paleogene period (70 million - 25 million years ago);

— Paleocene era ("the oldest part of the new era")(70 million - 54 million years ago);
— Eocene era ("dawn of a new era")(54 million - 38 million years ago);
— Oligocene era ("not very new")(38 million - 25 million years ago);

Neogene period (25 million - 1 million years ago);

— Miocene era ("relatively new")(25 million - 8 million years ago);
— Pliocene era ("very new")(8 million - 1 million years ago);

The Paleocene and Neogene periods are still combined in the Tertiary period. With the onset of the Cenozoic era (new life), a spasmodic spread of mammals occurs. Many large species have evolved, although many have become extinct. The number of flowering plants... With the cooling of the climate, herbaceous plants appeared. There has been a significant uplift of the land.

Quaternary period (1 million - our time);

— Pleistocene ("most recent")(1 million - 20 thousand years ago);

— Holocene epoch("A completely new era") (20 thousand years ago - our time).

This is the last geological period to include the present. Four major glaciations were interspersed with warmings. The number of mammals has increased; they've adapted to. The formation of man - the future ruler of the Earth - took place.

There are also other ways of dividing eras, eras, periods, eons are added to them, and some epochs are still divided, like on this table, for example.

But this table is more complex, confusing dating of some eras is purely chronological, not based on stratigraphy. Stratigraphy is the science of determining the relative geological age of sedimentary rocks, dismembering rock strata, and correlating different geological formations.

Such a division, of course, is relative, since there was no sharp, from today to tomorrow, distinction in these divisions.

But nevertheless, at the turn of neighboring eras and periods, significant geological transformations predominantly took place: the processes of formation of mountains, redistribution of seas, changing of the climate etc.

Each subsection was characterized, of course, by the originality of flora and fauna.

, and can be read in the same section.

Thus, these are the main eras of the Earth, on which all scientists rely. 🙂

The Phanerozoic Eon is part of geological time, dating back about 542 million years ago and continuing to the present day. Compared to the previous one (part of the geological history of the planet, including such eons as,), Phanerozoic is famous for the abundance of worlds.

Eras and periods

Phanerozoic is subdivided into three eras, which in turn consist of periods:

Palaeozoic

Mesozoic era

Cenozoic era

Geography

During the Phanerozoic, the continents drifted and eventually gathered into a single supercontinent known as Pangea, and then split into the present-day parts of the world.

Some scientists believe that the Phanerozoic eon began shortly after the collapse of the hypothetical supercontinent at the end of the global ice age. During the early Paleozoic era, a significant number of relatively small continents existed. By the end of the Paleozoic, the continents came together to form the Pangea supercontinent, which included most of the earth's landmass.

The Mesozoic era was characterized by a dramatic division of Pangea: into the northern continent of Laurasia and the southern continent of Gondwana. By the end of the era, the continents had practically taken on their present shape. Laurasia became North America and Eurasia, and Gondwana split into South America, Africa, Australia, Antarctica, and the Indian subcontinent.

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

Climate

During the Phanerozoic Eon, the Earth's climate varied between the conditions that supported the global continental glaciation, and rather tropical, with no permanent ice caps even at the poles. The difference in global average temperatures between fully glacial and non-glacial periods is estimated at about 10ºC, although much larger changes have been observed at high latitudes and less at low latitudes.

The evolution of CO2-absorbing (and oxygen-producing) organisms in the Precambrian led to the creation of an atmosphere as it is today, although for most of the Phanerozoic it had CO2 levels much higher than today. Likewise, the average temperature of the Earth has often been higher than it is today.

A life

Before the Paleozoic period, there was no atmosphere like there is now. When the amount of oxygen started to increase, the ozone layer was formed. At high altitudes, oxygen molecules are destroyed by ultraviolet radiation from the sun. These oxygen molecules combine together to create ozone.

A thick layer of ozone exists at an altitude of 15 to 35 kilometers. This layer ensures that harmful radiation from the sun does not reach the earth's surface. The thicker the ozone layer, the less harmful ultraviolet radiation hits the Earth. Before this protective function developed, animals primarily used. Consequently, the flora and fauna of the Phanerozoic were able to colonize the land. Early plants grew on land in the Silurian (about 430 million years ago). These were vascular plants such as ferns. Several species emerged very quickly.

They appeared in the Devonian, and reptiles - in the Carboniferous period. On the border of the Triassic and Jurassic (200 million years ago) mammals first appeared and, finally, birds. Mammals became the dominant animals after the extinction of dinosaurs at the close of the Cretaceous (66 million years ago).