The second mass extinction occurred 3 years ago. {} Late Devonian period 6.5 billion years ago. Also known as the Devonian mass extinction.

Devonian, the name of the geological chronology, the experts of crape myrtle used another term, but Zhang Binhui immediately reacted to the statement on the earth, and he automatically understood.

The Devonian is the Quaternary period of the Paleozoic Era, which began around 4. 0.5 billion years ago, ending at 3. 500 million years ago, lasting about 50 million years.

The Devonian is divided into three epochs: early, middle and late, and the strata are correspondingly divided into three systems: lower, middle and upper. The paleogeography of the Devonian period changed dramatically from the earlier Paleozoic.

It is manifested in the expansion of land area, the development of continental strata, and the great change in the appearance of the biological world. Terrestrial plants and ichthyomorphs developed unprecedentedly, amphibians began to appear, and the composition of invertebrates also changed significantly.

The Devonian period is the period when vertebrates flew over and developed, and fish flourished, and various types of fish appeared, so the Devonian period is called the "age of fish".

The most important thing is that evolved from the total fins, and the ancestors of amphibians and reptiles, tetrapods, that is, quadruped vertebrates, began to appear.

According to research, the Devonian period was warm. The fossil record shows that the climate was temperate as far away as the Arctic. The second mass extinction occurred in the late Devonian period, also due to the cooling of the Earth's climate and the retreat of the oceans.

About 3 years ago. 6.5 billion years ago, in the late Devonian period, after two peaks, 1 million years apart, the second species extinction event in the history of the earth occurred, and marine life was devastated.

The third mass extinction occurred during the Permian, the last epoch of the Paleozoic Era and an important coal-forming period.

The Permian is divided into Early Permian, Middle Permian, and Late Permian. The Permian period began about 2 years ago. 9.5 billion years, extended to 2. 500 million years, a total of 45 million years.

In the Permian, the crustal movement was relatively active, the relative movement between the paleoplates intensified, many troughs around the world were closed and folded mountains were formed one after another, and the paleoplates were gradually spliced together to form a joint paleocontinent.

At this time, the area of land was further expanded, the scope of the ocean was reduced, and the changes in the natural geographical environment promoted the important evolution of the biological world, heralding the arrival of a new period in the history of biological development.

2 years ago. 500 million years ago, at the end of the Permian period, the worst mass extinction event in history occurred, with an estimated 96% of the planet's species extinct with 90% of marine life and 70% of terrestrial vertebrates.

Trilobites, sea scorpions, and important coral groups have all disappeared. Terrestrial monobowed taxa and many reptile groups also became extinct.

The mass extinction caused the main organisms that had occupied the oceans for nearly 300 million years to decay and disappear, giving way to new species of life, and the most radical renewal of ecosystems, paving the way for the evolution of reptiles such as dinosaurs.

The crape myrtle scholar believes that the mass extinction was a milestone in the transition of Earth's history from the Paleozoic to the Mesozoic. The decline in marine life caused by other mass extinctions was less than one-sixth of the size of the species, and did not lead to such a major turning point in the evolutionary process.

Scholars believe that sea level decline and continental drift occurred during the Permian, causing the worst mass extinctions.

All the continents have coalesced into a united palaeocontinent, the rich coastline has been drastically reduced, the continental shelf has shrunk, ecosystems have been severely damaged, and many species have become extinct because of the loss of living space.

To make matters worse, when the shallow continental shelf is exposed, the organic matter previously buried in the seafloor is oxidized, a process that consumes oxygen and releases carbon dioxide. The reduced amount of oxygen in the atmosphere is very bad for animals living on land.

As the temperature rises and the sea level rises, many terrestrial organisms have been wiped out, and the ocean has become an oxygen-deficient zone. The abundance of organic-rich shale deposits in the strata is proof of this disaster.

The scholar believes that the mass extinction phenomenon on the earth is caused by a series of causes such as sudden climate changes, the expansion of deserts, and volcanic eruptions.

The fourth mass extinction occurred in the Triassic, the first epoch of the Mesozoic Era, where reptiles and gymnosperms rose, and it was located between the Permian and Jurassic periods.

The Triassic period began 2 years ago. 500 million to 2. 0.3 billion years, which lasted for about 50 million years. After the Hercynian movement, many troughs were transformed into mountain systems, the land area expanded, and some inland basins were created in the platform area.

New paleogeographic conditions have led to changes in sedimentary facies and biologics. Since the Triassic, continental sediments have been abundant all over the world, especially in China and other parts of Asia.

In terms of paleoclimate, the early Triassic inherited the characteristics of drought at the end of the Permian. After the middle and late periods, the climate transitioned to damp heat, resulting in the occurrence of coal-bearing deposits in red rock formations and the development of xerophytic plants to damp-hot plants. At the same time, the phytogeographic regions were differentiated.

1 year ago. At the end of the Triassic period, 9.5 billion years ago, an estimated 76% of species, mainly marine life, went extinct.

When he saw the analysis of the fifth mass extinction, Zhang Binhui's spirit perked up, because this is knowledge that he is relatively familiar with, and there are also in-depth research theories on the earth, and even a large number of them are reflected in literary works.

Because, this extinction, the invincible dinosaurs that ruled the earth disappeared.

On Earth, we call this extinction the White Age Mass Extinction or the Dinosaur Mass Extinction.

The White Period is the last epoch of the Mesozoic Era, which began 1 year ago. 3.7 billion years, ending 65 million years ago, with 70 million years in between.

Both the inorganic and organic worlds have undergone important changes in the White Age. Located in the lower Jurassic and above the Cenozoic.

The White Period was the most submerged period of the Earth's surface during the Mesozoic, during which the Northern Hemisphere deposited extensive white beds.

The white bed, a very fine and pure silty limestone, is a marine sediment of biogenetic origin, consisting mainly of calcareous ultrafine fossils called lithophyllum and fossils of planktonic foraminifera.

At the end of the White Age, 65 million years ago, the fifth mass extinction event occurred in the history of the earth, with about 75% and 80% of species extinct.

Of the five mass extinctions, this one is the most famous, as the 140 million-year-long age of dinosaurs ended here and ammonites disappeared from the ocean.

Its greatest contribution was to eliminate the dominant dinosaurs and their kind on Earth, and to provide the opportunity for the final appearance of mammals and humans.

The catastrophe came from extraterrestrial space and volcanic eruptions, and one or more meteorite showers that occurred at the end of the White Age caused the collapse of global ecosystems.

The impact sent so much gas and dust into the atmosphere that sunlight could not penetrate it, global temperatures plummeted, and black clouds obscured the Earth for a few tenths to millions of years.

Plants are not getting their energy from sunlight, algae and forests are dying in the oceans, the foundations of the food chain are being destroyed, and animals are dying of starvation, including dinosaurs.