Dividing the history of the Earth on the era and periods. Once the earth looked like an alien place! What was 4 billion years ago
An interesting service appeared in the global network (dinosaurpictures.org), which allows you to see how our planet did it look like 100, 200, ... 600 million years ago. Listing events occurring in the history of our planet is shown below.
Nowadays
. On earth, there are practically no places that do not have human activity. 
20 million years ago
Neugenic period. Mammals and birds begin to resemble modern views. The first hominids appeared in Africa. 
35 million years ago
The middle tier of Pleistocene in the era of the cheruthetic period. In the course of evolution of small and simple mammals, more complex and varied species have appeared. Primates, cetaceans and other groups of living organisms are developing. The land cools, the destruction of deciduous species of trees is obtained. The first types of herbaceous plants evolve. 
50 million years ago
The beginning of the tertiary period. After the asteroid destroyed dinosaurs, surviving birds, mammals and reptiles, evolving, occupy the liberated niches. From terrestrial mammals, a group of cetacean ancestors, which begins to master the expanses of the oceans are bothering. 
65 million years ago
Late chalk. Mass disappearance of dinosaurs, sea and flying reptiles, as well as many marine invertebrates and other species. Scientists adhere to the opinions that the cause of extinction was the fall in the asteroid in the region of this Peninsula Yucatan (Mexico). 
90 million years ago
Cretaceous period. Triceratops and Pakhiceophalosaurians continue to raise triceratops and pakhicoofalosaurs. The first types of mammals, birds and insects continue to evolve. 
105 million years ago
Cretaceous period. Triceratops and Pakhiceofalosauria and Pakhiceofalosauria are enveloped on Earth. The first types of mammals, birds and insects appear. 
120 million years ago
Early chalk. On Earth, heat and humid, the ice polar caps are absent. Reptiles dominate the world, the first small mammals lead a semi-width lifestyle. Flower plants Evolve and apply throughout the Earth. 
150 million years ago
The end of the Jurassic period. The first lizards appeared, they evolve primitive placental mammals. Dinosaurs dominate all land. The world ocean inhabited marine reptiles. Pterosaurs become dominant vertebral in the air. 
170 million years ago
Jurassic period. Dinosaurs flourish. The first mammals and birds evolve. Ocean's life is distinguished by a variety. The climate on the planet is very warm and wet. 
200 million years ago
Late Triassic. As a result of mass extinction, 76% of all types of living organisms disappear. The number of populations of surviving species is also very reduced. Types of fish, crocodiles, primitive mammals, as well as Pterosaurov suffered to a lesser extent. The first real dinosaurs appear. 
220 million years ago
Middle Triassic. The land is restored after the Perm-Triassic extinction. Small dinosaurs begin to appear. Together with the first flying invertebrates, therapisids and arconsaws appear. 
240 million years ago
Early Triassic. Because of the death of a large number of types of terrestrial plants, there is a low oxygen content in the planet's atmosphere. Many types of corals disappeared, there will be many million years before the surface of the earth will begin to raise coral reefs. Small the ancestors of dinosaurs, birds and mammals survive. 
260 million years ago
Late Perm. The most massive extinction in the history of the planet. About 90% of all types of living organisms disappears from the face of the Earth. The disappearance of the majority of plant species leads to the hungry death of a large number of types of herbivore reptiles, and then predatory. Insects are deprived of habitats. 
280 million years ago
Perm period. Sushi arrays merge together and form Superkontinet Pangé. Climatic conditions worsen: polar caps and deserts begin to grow. The area suitable for growing plants is sharply reduced. Despite this, the four-legged reptiles and amphibians are diverged. Oceans are replete with various kinds of fish and invertebrates. 
300 million years ago
Late carbon. The plants have a developed root system, which allows them to successfully set out the hard-to-reach land plots. The surface area of \u200b\u200bthe land occupied by vegetation increases. The oxygen content in the planet's atmosphere also increases. Life begins to actively develop under the canopy of ancient vegetation. Evolving the first reptiles. There are many diverse giant insects. 
340 million years ago
Carbon (coal period). On Earth there is a massive extinction of marine organisms. Plants appear a more perfect root system, which allows you to more successfully seize new land plots. Oxygen concentration in the atmosphere of the planet increases. The first reptiles evolve. 
370 million years ago
Late Devon. As the plants develop, life on land becomes more complicated. Appears a large number of species of insects. Fish appears strong fins, which ultimately develop in limbs. The first vertebrates crawl into land. Oceans are replete with corals, various types of fish, including sharks, as well as marine scorpions and charts. The first signs of mass extinction of marine living organisms begin to appear. 
400 million years ago
Devonian. Plant life on land is complicated, accelerating the evolution of terrestrial animal organisms. Insects are diverged. The species diversity of the world's ocean increases. 
430 million years ago
Silico. Mass extinction erases from the face of the planet half species diversity Sea invertebrates. The first plants begin to master the land and settles coastal stripe. The plants begin to develop a conductive system that accelerates the transport of water and nutrients to the tissues. Marine life becomes more diverse and numerous. Some organisms leave reefs and justified on land. 
450 million years ago
Late Ordor. The sea is replete with life, coral reefs appear. Algae are still the only multicellular plants. Sophisticated life on land is missing. The first vertebrates appear, including condimensional fish. The first harbingers of the mass extinction of the sea fauna appear. 
470 million years ago
Ordovik. Marine life becomes more diverse, corals appear. Sea algae are the only multicellular vegetation organisms. The simplest vertebrates appear. 
500 million years ago
Late Cambrian. The ocean is simply teeming with life. This period of turbulent evolutionary development of a multitude of forms of marine organisms was called "Cambrian Explosion". 
540 million years ago
Early Cambrian. Mass extinction takes place. In the course of evolutionary development, marine organisms appear sinks and exoskells. Fossil remains testify to the beginning of the "Cambrian explosion".
Before the emergence of people, the world was completely different. Our planet did not always look like now. Over the past 4.5 billion years, she experienced incredible changes that you did not imagine. If you could go back and visit the land millions of years ago, you would see someone else's planet, as if departed from pages of fantastic books.
1. Giant mushrooms grew throughout the planet
Approximately 400 million years ago, the trees were about the waist of a person. All plants were much smaller than the current - besides mushrooms. They grew 8 meters in height, and their leg (or already the trunk?) Was a diameter of 1 meter. They did not have such big caps that we associate today with mushrooms. Instead, they were just sticking pillars. But they were everywhere.
2. The sky was orange, and the oceans were green
The sky was not always blue. About 3.7 billion years ago, as they believed, the oceans were green, the continents are black, and the sky looked like an orange haze. The oceans were green, because the iron was dissolved in seawater, leaving a green rust. The continents were black due to lack of plants and lava coverage. The sky was not blue, because instead of oxygen there was mainly attended by methane.
3. Planet smelled with rotten eggs
Scientists are confident that they know how it smelled sometime on our planet. And it was a distinct smell of rotten eggs. All this is because 2 billion years ago, the oceans were filled with gaseous bacteria that feeds the salt and the hydrogen sulfide, filling the air of the stench.
4. Planet was purple
When the first plants appeared on Earth, they were not green. According to one theory, they would be purple. It is believed that the first life forms on Earth partially absorbed the light from the sun. Modern plants are green, because they use chlorophyll to absorb sunlight, but the first plants used the retina - and it gave them a bright shade of violet. Purple, perhaps, was our color for a long time.
5. The world looked like a snowball
We all know about the ice age. However, there is evidence that one of the glacial periods is 716 million years ago was very extreme. It is called a period of "Snow Earth", because the earth may have been so covered with ice that she literally looked like a giant white snowball, floating in space.
6. Acid rain fell on Earth for 100 thousand years
In the end, the period of the Snow Earth ended - with the most terrible way, which can be imagined. Next began "intensive chemical weathered." In other words, an acid rain is constantly lilted from the sky - and so 100 thousand years old. He melted the glaciers covering the planet, "sent" into the ocean nutrients and allowed life to be nascent under water. Before life began to appear on Earth, the planet was a poisonous, non-shitty desert.
7. The Arctic was green and densely
Approximately 50 million years ago, the Arctic was a completely different place. It was the time called the Epoch of the Early Eocene, and the world was very warm. Palms grew in Alaska, and crocodiles were swimming off the shores of Greenland. The Northern Arctic Ocean was probably a giant freshwater reservoir that aburred living beings.
8. Dust blocked the sun
When 65 million years ago, the asteroid crashed into the ground and destroyed dinosaurs, chaos did not end. The world turned into a gloomy and terrible place. All dust, soil and rocky rocks rose into the atmosphere and even into space, enveloping the planet with a huge layer of dust. The sun disappeared from the sky. It continued not long, but even when a huge cloud of dust disappeared, sulfuric acid remained in the stratosphere and got into the clouds. And again the time of acid rain came.
9. Waughted rains from liquid hot magma
However, the previous asteroid was a children's game compared with the one that crashed into a planet of 4 billion years ago and turned it into the hellish landscape. Oceans on the planet boiled. The heat from asteroid strike was actually ended with the evaporation of the first oceans on Earth. Huge parts of the surface of the Earth melted. Magnesium oxide rose into the atmosphere and condensed in a drip of a liquid hot magma falling in the form of rain.
10. Giant insects were everywhere
About 300 million years ago, the planet was completely covered with low-lying marsh forests, and the air is filled with oxygen. 50% more oxygen than today, and it created an incredible surge of life development ... and the emergence of huge and terrible insects. For some creatures, oxygen in the atmosphere was too redundant. Small insects could not cope with it, so they began to actively increase in size. Scientists have found fossil dragonfly remains that were the size of a modern seagull. By the way, they most likely were carnivorous predators.
The science
Today, our neighbor Mars is a cold, covered with the Red Desert Planet. Liquid water No longer exists on its surface due to low atmospheric pressure and temperature. However, there is evidence that on its surface once flowed flows solonish liquid with a reduced freezing temperature.
Water on Mars under modern conditions can be ice, or can turn into steam, milling liquid state.
Ancient Mars
It turns out about 4 billion years agowhen Mars was a young planet, his atmosphere was more dense, and the surface was warm enough to maintain the liquid water condition, which is very an important condition for the existence of life.
On the surface of Mars, as on the surface of the earth, there are characteristic branched canalswhich were formed by fluid flows. In the inside of some shock crater, there are pools in which the lakes sometimes splashed.
Small craters disappeared over time, and larger retained signs of erosion. Water destroyed breed near 3.7 billion years ago. Seaming layers are noticeable on the walls of the crater. There are also minerals that could have been formed solely in the presence of water.
Animation presented in the next video shows what a red planet could be in those distant times when on its surface there was liquid water. Fast moving clouds symbolize time stroke. Shown a gradual transition from warm and wet to a cold and dry climate. The lakes dry and freeze, and the sky changes the color from gently blue to dirty pink:
Until it is not clear is it enough long enough A favorable climate has retained on Mars and whether life has managed during this time.
The earliest signs of earthly life Presented in the form of an organic chemical structure found in rocks on the territory of Greenland Island. Once these breeds were on the seabed. Approximate age structure - 3.8 billion years old, that is, after the formation of our planet, only passed 700 million years. Petrified remains of life, which would be dated with this period, was found yet.
Fossils of really existing microorganisms, according to some estimates, 3.5 billion years old. By that time, the conditions favorable the appearance of life had already disappeared on Mars.
Comparison between the histories of two planets should be carried out with caution, researchers warn, because chemical composition The surfaces of the Earth and Mars differ, as well as their volcanic activity.
How did life originate on earth?
Earth appeared approximately 4.5 -5 billion years ago From cosmic dust and at first was a split ball.
The ancestor of all creatures living on our planet Last universal overall ancestor. He lived approximately 3.5-3.8 billion years ago. This ancestor cannot be considered the first living creature of our planet.
The hypotheses of the origin of life on our planet there are several, including self-religion hypothesis and hypothesis life Cosmos, Including from other planets, for example, from Mars.
According to one of the most popular versions, life on Earth appeared after it was sufficiently liquid water And there are special climatic conditions.
The first live creatures were procarniot, unicellular creatures without decorated kernel. These creatures were similar to modern bacteria. Alive organisms over long million years have evolved and became more complicated.
- 1000-600 Million years ago On Earth there was already jellyfish, mollusks, iglozzhe, polyps and flat worms.
Appearing in the ancient Ocean, some animals began to gradually get into land, others remained swimming in the water. This happened 416-360 million years ago in Devonian period.
The birth of life on Earth occurred about 3.8 billion years ago, when the formation of the earth's crust ended. Scientists found out that the first living organisms appeared in the aquatic environment, and only a billion years have extended to the surface of the sushi of the first creatures.
The formation of terrestrial flora contributed to the formation of organs and tissues in plants, the ability to multiply by disputes. Animals also evolved significantly and adapted to life on land: there was an internal fertilization, the ability to lay eggs, pulmonary breathing. An important stage of development was the formation of a brain, conditional and unconditional reflexes, survival instincts. The further evolution of animals gave the basis for the formation of humanity.
The division of the history of the Earth on the era and periods gives an idea of \u200b\u200bthe features of the development of life on the planet in different time intervals. Scientists allocate particularly significant events in the formation of life on Earth into separate segments of time - era, which are divided by periods.
There are five er:
- Archean;
- proterozoic;
- paleozoic;
- mesozoic;
- cenozoic.
The Archean Era began about 4.6 billion years ago, when the planet earth only began to form and there were no signs of living on it. Air contained chlorine, ammonia, hydrogen, the temperature reached 80 °, the level of radiation exceeded the permissible boundaries, under such conditions the birth of life was impossible.
It is believed that about 4 billion years ago, our planet collided with the heavenly body, and the result was the formation of the Earth's satellite - the Moon. This event has become significant in the development of life, stabilized the axis of rotation of the planet, contributed to the purification of water structures. As a result, first life originated at the depths of the oceans and the seas: the simplest, bacteria and cyanobacteria.
Proterozoic era lasted about 2.5 billion years to 540 million years ago. Detected residues of single-cell algae, mollusks, ringed worms. Begins to form the soil.
The air at the beginning of the era has not yet been saturated with oxygen, but in the process of the life of the bacteria, the inhabable seas, they began to more and more allocate O 2 into the atmosphere. When the amount of oxygen was at a stable level, many creatures took a step in evolution and switched to aerobic breathing.
Paleozoic era includes six periods.
Cambrian period (530 - 490 million years ago) is characterized by the emergence of representatives of all types of plants and animals. Oceans inhabited algae, arthropods, mollusks, the first chord (Haikoichtis) appeared. Susha remained unnecessary. The temperature was maintained high.
Ordalic period (490 - 442 million years ago). The first settlements of lichens appeared on land, and Megal Proppte (representative of arthropod) began to go ashore to postpone the caviar. The ocean continues to develop vertebrates, coral, sponges.
Silurian (442 - 418 million years ago). Plants come to the land, the figurative fabric is formed in arthropods. The formation of the bone skeleton from vertebrates is completed, sensory authorities appear. There is a population, different climatic zones are formed.
Devonian (418 - 353 million years ago). Characteristic the formation of the first forests, mainly fern. Bone and cartilage appear in the reservoirs, amphibians began to go to the land, new organisms are formed - insects.
Coal period (353 - 290 million years ago). The appearance of amphibians, the launch of the continents occurs, at the end of the period there was a significant cooling, which led to the extinction of many species.
Perm period (290 - 248 million years ago). The land inhabit the reptiles, therapists appeared - mammalian ancestors. The hot climate led to the formation of deserts, where only persistent ferns and some conifers were able to survive.
The Mesozoic Era is divided into 3 periods:
Triassic (248 - 200 million years ago). Development gamed plants, The appearance of the first mammals. Split sushi to continents.
Jurassic period (200 - 140 million years ago). Appearance covered plants. The appearance of bird ancestors.
Cretaceous period (140 - 65 million years ago). Covenate (flowering) became the dominant group of plants. Development of higher mammals, real birds.
The Cenozoic Era consists of three periods:
LOWINTERIC PERIOD or Paleogen (65 - 24 million years ago). The disappearance of the majority of challenges, lemurs and primates, later parapite and driming appear, appear. The development of the ancestors of modern mammals - rhinos, pigs, rabbits, etc.
Upperretical period or neogen (24 - 2.6 million years ago). Mammals inhabit sushi, water expanses, air. The appearance of Australopitets is the first ancestors of people. During this period, Alps, Himalayas, Andes were formed.
Quaternary period or anthropogen (2.6 million years ago - our days). The significant event of the period is the emergence of a person, first Neanderthal, and soon Homo Sapiens. The vegetable and animal world gained modern features.
People are confident that the satellite of the Earth is the only space object appearing in the night sky. However, scientists after the study of the ancient sources found out that three moon of 4 billion years ago illuminated the Earth before the destruction of two celestial bodies with space catastrophes.
The ancient German mythology calls the world of people Midgard, who was protected by celestial bodies from the dangerous exposure to space. Thanks to the power of gravity, they could slow the rotation of the Earth, increasing the duration of the day. Experts have long been interested in such a phenomenon, and the researchers suggested that the moon were created by highly developed creatures that have unique technologies. There are in the Vedas detailed description The death of Leli, which was located closer to the rest of the objects to the planet.
It happened 122,000 years ago, when the civilization of aggressive aliens invaded her surface, which decided to seize earthlings. They built a military base on it, but the ancestors at the time noticed the threat and destroyed the enemy, only the fragments of the destroyed satellite after the fall had caused the emergence of the first world focus and glacial period. The northern hemisphere was covered with snow, and people and animals were forced to relocate for the Ural Mountains.
Slavs in memory of such events celebrated the feast of the Easter, where the tradition appeared to check the fortress of painted eggs. The strongest of them was a symbol of the Power of Dazhbog, and the broken analogue personified the moon destroyed by the evil forces and was always given to the egregious animals. Fatt was the second satellite of the planet and saw the greatness of Atlantis. Here is just an irrepressible thirst for the power of the disappeared civilization that used the power of the elements during the creation of its devastating technologies led to a violation of the space balance.
The satellite with orbit, and the Earth began to rotate faster around the axis, after which the year increased for 5 days. In Maya's calendars, information about strong impact after the collision of the celestial bodies, which shifted tectonic platforms. The oceans and the sea came out of the banks and began to fit all on their way, while the ancient volcanoes were awakened and new formed new natural objects, rising from earthly subsoil. The ashes closed the sun and caused a new end of the world described in all religions.
Humanity was discarded in the Stone Age and again learned to survive in unusual conditions after the planetary catastrophe. Modern scientists are confident that the missing mows had a natural origin, because they found a huge "heavenly field" during the study of the Argentine district of Campo del Siela. The legends of the Indians are talking about a huge ball, fallen from heaven, and the Spaniards made weapons from a piece of cosmic iron block.
In the 16th century, a local resident also took the material from here for personal needs, after which a scientific expedition arrived here along with Don Rubin de Cellis. Archival documents recorded a meteorite, weighing 15 tons, only then he disappeared without a trace. Another space fellow was found in 1803, and a piece of Dara Heaven bought British Woodbine Daryish, who passed it to the museum staff. Until now, archaeologists face a large accumulation of celestial bodies and crater at a 17-kilometer plot that intrigued American scientist Kesside.
When he found here a lot of small wreckage of the heavenly body out of 100% iron, it immediately noticed some oddity. In the explosion of meteorite, pieces can only get on the 2-meter territory, which cannot be said about this area. After the analysis, the expert concluded that it was the missing second moon, attracting to the ground to the Rosh's limit, after which it crumbled into parts.
The fire caused by the fall of the wreckage of the heavenly body arose 6000 years ago, and in 2016 scientists noticed quasilun, located on the earthly orbit of 100 years, and not going to leave her several centuries. The asteroid has a 100-meter diameter and became a planet satellite, approaching the Sun or hiding in her shadow, but it is not a threat to humanity.
