The history of the Earth before the appearance of hominids

Main article: Earth (planet)

560 million years of evolution in a few seconds in the video below.

Aeons and eras

Phanerozoic

30 million hp: The beginning of the formation of the East African fault

Main article: East African Fault (rift valley)

The separation of the African tectonic plate from the Arabian plate is a continuation of the decay of the supercontinent Gondwana and began about 30 million years ago. The space of the rift began to fill the water and the Red Sea was formed.

35 million hp: The appearance of giant sloths

• Ground (giant) sloths

40 million hp: Demarcation of Australia and Antarctica

40 million years ago (during the Cenozoic era), the demarcation of Australia and Antarctica occurred.

50 million hp: The clash between India and Laurasia forms the Himalayas

The movement of the continents breakaway from Gondwana and their collision with parts of Laurasia led to active mountain formation. Africa's pressure on Europe resulted in the Alps, and the clash between Hindustan and Laurasia (50 Ma) created the Himalayas.

54 million-year-old gecko in amber.

70 million hp

Mediterranean fold belt formed on the border of Gondwana and Laurasia

About 70 million years ago, the Mediterranean folded belt was formed in its modern form. It separates the southern group of ancient platforms, which constituted the supercontinent Gondwana until the middle of the Jurassic period, from the northern group, which formerly constituted the continent of Laurasia and the Siberian platform.

This belt includes the southern regions of Europe, Northwest Africa, Alps, Carpathians, Crimea, Caucasus, Persian mountain systems, Kopet Dag, Pamir, Himalayas, Tibet, Indochina and Indonesian islands.

An oceanic bottom has formed between Hindustan and Madagascar

The first oceanic bottom formed between Madagascar and India about 70 million years ago

Quetzalcoatls

Quetzalcoatlus is one of the largest known members of the pterosaur order. The only species is Quetzalcoatlus northropi. Wingspan 10-11 meters.

Found in Late Cretaceous sediments of North America (habitat - about 70 million years ago).

Northrop's quetzalcoatl compared to a 1.80m tall man.

90 million hp: The separation of Hindustan and Madagascar

90 million years ago there was a separation of Hindustan and Madagascar.

100 million hp: South America separated from Africa. The emergence of the Atlantic Ocean

100 million years ago, South America separated from Africa, in the gap between which the Atlantic Ocean began to form.

125 million hp: East Gondwana split into Indigaskar and Australo-Antarctica. The emergence of the Indian Ocean

125 million years ago, East Gondwana split into Indigaskar and Australo-Antarctica, between which the Indian Ocean began to form.

137 million hp

175 mln hp: Formation of the Big Caucasus basin

The split of South America and Africa (with Arabia) led to an increase in the oceanic lithosphere between them and, which is very important for the Caucasus, to a reduction in the distance between Africa and Eurasia. The Tethys Ocean began to shrink in size.

Where the oceanic crust of the Tethys Ocean pushed hard under the edge of the Scythian Plate, this edge weakened. This is due to the fact that the ocean plate, going down, melts, and the excess of molten matter tries to break up.

Rifting began to occur on the weakened edge of the plate - the formation of rifts with the extension of the split fragments of the previous base. The new crust was expanding toward the ocean. The crust was generally continental, granite, but broken by outpourings of basalts. So (at the end of the Lower and beginning of the Middle Jurassic, something about 175 million hp) the so-called Big Caucasus basin was formed. It was a marginal sea. It was separated from the main ocean of Tethys by an island volcanic arc, the existence of which is also explained by the weakening of the lithosphere in the subduction zone, the sub-wave, and the breakthrough of magma to the surface with the formation of volcanoes. The Big Caucasus Basin was extended 1700-1800 km long and 300 km wide.

179 million hp

183 million hp: The beginning of the collapse of Gondwana in the southern hemisphere

183 million years ago (Mesozoic) Gondwana began to break up into two parts: western (, Africa Arabia and) South America and eastern (,, and Australia Antarctica Madagascar Hindustan), the border of which became the Mozambique Strait after 25 million years.

230 million hp: The collapse of Pangea. Laurasia broke up into Eurasia and North America

As geologists know, supercontinent formations are unstable. Immediately after formation, the supercontinent tends to disintegrate. The reason for this is that the same mantle flows that bored the continents collided with them. Following the formation of the supercontinent, the lithosphere, which goes under it from all sides in the subduction zones, accumulates under it, and then floats up, splitting the supercontinent.

The Triassic period (250-200 million hp, this is the first period of the Mesozoic era) was just the time of the beginning of the split of Pangaea. The blocks of lithospheric plates that made up Pangea began to move away from each other. Africa and Eurasia began to move away from each other. The crushing of the continental bridge between Europe, Africa and America began.

When the continental blocks are separated from each other, the oceanic crust located between these blocks builds up (in fact, this is the extension). Growth occurs when a new crust is formed in the mid-ocean ridges.

Splits that occurred about 230 million years ago (between the Paleozoic and Mesozoic) formed new continents. Thus, Laurasia broke up into Eurasia and North America.

232 million hp

233 million hp: The appearance of dinosaurs

Main article: Dinosaurs

Dinosaurs originated in the Triassic period, between 243 million and 233.23 million years ago.

250 million hp: Mainland Siberia connects with Pangea to complete the formation of the supercontinent

About 250 million hp mainland Siberia connects with Pangea, completing the formation of supermaterics.

Map by Massimo Pietrobon

251 million hp

275 million hp

Dragonfly, a 250-300 million-year-old fossil with a wingspan of 60 cm.

310 million hp: The connection of the continents of Laurasia in Gondwana forms the mainland of Pangea

About 310 million years ago, the connection of the continents of Laurasia in Gondwana forms the mainland of Pangea.

374 and 359 million hp: Two stages of the Devonian extinction, the death of 50% of childbirth from radiation

About 374 and 359 million years ago, the so-called Devonian extinction occurred in two stages - the mass extinction of flora and fauna on Earth. It occurred at the end of the Devonian, one of the periods of the Paleozoic era. About half of all existing genera disappeared from the face of the Earth. For example, of the jawless, only lampreys and mollusks survived to this day.

The hypothesis about the depletion of the Earth's ozone layer from star explosions

Such global extinctions are generally thought to be caused solely by terrestrial causes: for example, a volcanic eruption or an asteroid impact. But in 2020, scientists believe that the culprits of the Devonian extinction should not be sought on Earth, and not even in the solar system. Brian Fields, an astrophysicist at the University of Illinois, has conducted research with colleagues that suggests the exploding star^[1].

In their work, the researchers decided to consider a sharp decrease in ozone levels, coinciding in time with the Devonian extinction, as a consequence of astrophysical phenomena, and not a volcanic eruption or an episode of global warming. For example, radiation effects from a supernova explosion, or even several stars that were about 65 light-years away from Earth, may well have caused the ozone layer to deplete and eventually lead to disaster. And phenomena such as meteorite impacts, solar eruptions and gamma-ray bursts are short-term events and are unlikely to cause long-term destruction of the ozone layer, which caused the extinction.

Supernovae are a source of ultraviolet, X-ray and gamma radiation. After the explosion, the fragments collide with the surrounding gas, which causes the acceleration of photons. Thus, supernovae of stars after an explosion generate accelerated cosmic radiation, which is held for some time by a magnetic field inside the remains of the star. But it is able to reach the Earth and destroy its ozone layer, causing radiation damage to various life forms for about 100 thousand years.

Fossils found, for example, deformed spores of ancient plants, indicate a decrease in biodiversity in the Devonian period, which lasted about 300 thousand years and led to global extinction. This duration suggests the possibility of multiple supernova explosions, especially since giant stars usually form in clusters with other giants.

The authors of the study believe that the key to proving a supernova explosion will be the radioactive isotopes of plutonium-244 and samarium-146 (Pu-244 and Sm-146) in rocks and fossils formed during the Devonian extinction. They do not meet at all on Earth and could get here exclusively through space explosions. Now researchers have to find these isotopes in fossilized rocks formed at the junction of Devonian and Carboniferous.

Also in their work, scientists suggest that in the future, exploding stars could be life-threatening on Earth due to a possible combination of both instantaneous and delayed effects.

380 million hp: The oldest discovered heart in the world

In mid-September 2022, scientists from Curtin University discovered in Western Australia a perfectly preserved heart of ancient fish along with a fossilized stomach, as well as intestines and liver. The heart is 380 million years old and this is a record, and the find itself will help in the study of the evolution of jaw vertebrates. Scientists noted that the soft tissues of ancient species are rarely preserved.

According to a study published in the journal Science, the arrangement of organs in the body of arthrodirs, an extinct class of shell fish that flourished during the Devonian period from 419.2 million years ago to 358.9 million years ago, is similar to the anatomy of modern sharks, providing new evolutionary clues.

Curtin University scientists discover perfectly preserved heart

Exceptional in finding fish is that their soft tissue is preserved in three dimensions. In most cases, soft tissue is preserved in flattened fossils, where soft anatomy is nothing more than a spot on the stone.

The researchers used neutron beams and synchrotron X-rays to scan samples still in limestone nodules and constructed 3D images of soft tissues inside them based on varying densities of minerals deposited by bacteria and surrounding rock.

{{quote 'As a paleontologist who has been studying fossils for more than 20 years, I was really amazed to find a three-dimensional and perfectly preserved heart in 380 million ancestors! For the first time, we can see all the organs together in primitive jawfish, and we were especially surprised to learn that they are not so different from us, "said Kate Trinajstic, lead researcher and professor of paleontology at the University of Australia. }} The results demonstrate for the first time a 3D model of a complex S-shaped arthrodir heart consisting of two chambers, with a smaller camera located on top. These features are considered advanced for such early vertebrates, offering a unique window into how the head and neck area began to change to accommodate the jaws, a critical step in the evolution of the human body.

The liver was large and allowed the fish to maintain buoyancy like modern sharks. However, scientists point to one critical difference. Some modern bony fish, such as lungfish and birch forests, have lungs that have evolved from swimming bubbles, but researchers have found no evidence of lungs in extinct shell fish. This suggests that modern lungs developed independently in bony fish at a later time.^[2]

500 million hp: The first creatures have a brainstem

500 000 000 - years ago, the first creatures on Earth had a brainstem - it is the same as the brain of modern reptiles.

An excellent preserved rilobite ~ 500 million years old.

Precambrian

1.7 billion hp: Pramaterik Pangea split into Laurasia and Gondwana. Between them is the Tethys Ocean

About 1.7 billion years ago, during the Proterozoic era, the pramaterik Pangea, then occupying one third of the Earth's surface, split into two continents - the northern mainland of Laurasia and the southern mainland of Gondwana. Between them stretched the Tethys Ocean, stretching for 20 thousand km.

3.5 billion hp: Minerals became part of a living cell

Main article: The body's need for minerals

Minerals became part of a living cell at the very beginning of biological evolution - about 3.5 billion years ago, and the lack of any of them causes disorders in the work of the entire human body until now.

4.6 billion hp: Catharcheus: Earth formation and asteroid bombing

Main article: Catharcheus (Gadey, Prearchean)

See also

• History
• Timeline of the Universe before the advent of planet Earth

Links

Geochronological scale on Wikipedia