According to the long-term research of archaeologists, there have been five mass extinctions in the history of the earth. The earliest event occurred at the end of Ordovician 440 million years ago, followed by the late Devonian 365 million years ago, then the late Permian 250 million years ago, the fourth was the late Triassic 200 million years ago, and the last mass extinction was the closest to us, that is, 65 million years ago. These five mass extinctions have been recognized by the archaeological community, indicating the turbulent course of the earth in the past.

In addition to these five mass extinctions, there have been many small-scale extinctions in history, but in August last year, the American magazine Science Progress published a paper about the extinction events that happened on the earth 233 million years ago. The paper points out that during this period, great changes have taken place in the earth's climate, which led to the extinction of a large number of creatures that could not adapt to the environment. In that event, dinosaurs boarded the throne of the biosphere, which was called the "Canyon Flood Event".

So how did scientists discover this event? How did the Canyon flood event put dinosaurs on the throne?

What unexpected discoveries did early scientists make in rocks?

For a long time, geologists have found some geological phenomena on different continents that can prove Triassic, among which red sandstone is a typical feature. Geologists have discovered the existence of red sandstone in northern Italy, southern Alps and southern China, and there is obvious rapid precipitation of carbonate rocks in red sandstone. Both findings indicate that there was a very dry climate during the Triassic period, which enveloped the whole earth at that time.

However, since 1980s, Alastair Luffer, a British geologist, has discovered species that do not seem to belong to Triassic, such as silt and riverbed sediments. The reason why these substances are incompatible with Triassic rocks is that the Triassic climate is very dry, and these substances will only form in a humid climate. This phenomenon appears not only in Britain, but also in North America, South America, Asia and Oceania.

This shows that the entire Triassic climate is not completely dominated by drought, and there should be a wet period in each period, which has occurred all over the world. According to the development process of the earth's climate, there is usually a warming process before the emergence of dry climate, and then a wetting period is triggered. After the wetting period has passed, the dry climate will follow. Therefore, geologists speculated in the last century that climate warming occurred on the earth during the Triassic period, which led to a rare rainstorm period on the earth.

This rainstorm period is the "Kani Flood Event". According to research, in this incident, the earth maintained a rainy period of two million years, and the sudden heavy rainfall led to the extinction of a considerable part of the species on the earth.

How was global warming formed in that period?

In order to find out the causes of the flood events during the Kani period, we must first find out how the climate warming happened before that period. Geologists put forward a classic hypothesis from geological exploration that large-scale volcanic eruptions are caused by large-scale plate movements. Before the Carney period, the earth continent was almost a whole, and then it gradually fell apart under the influence of the earth plate movement. The east side of the mainland split into two parts, forming North America and South America, so the position formed after the split formed a huge ocean, that is, the Pacific Ocean.

The appearance of the Pacific Ocean makes the surrounding continental plates have more water vapor transport, which makes the original inland areas become coastal areas, and the climate changes from drought to humidity. At the same time, due to the large-scale movement of the plate, a large-scale volcanic eruption occurred on the earth, which was called "Langlia Volcano Eruption" in history. As we all know, volcanic eruption will lead to the emission of greenhouse gases such as carbon dioxide and methane into the atmosphere, which will further promote the occurrence of climate warming.

On the one hand, the change of continental plate leads to the increase of ocean water vapor, on the other hand, volcanic eruption leads to global warming. The combination of these two factors led to the increase of rainfall in many areas, which lasted for about 2 million years, making the earth change from a dry planet to a wet planet in a short time. Is there any evidence that these phenomena really happened on earth? Geologists say that most of the amber we found today was formed at that time.

The increase of rain causes plants to secrete more resin for self-protection, otherwise the outcome will only be death. Fortunately, some small insects did not disappear in the Kani flood, but were wrapped in resin. After thousands of years of geological action, precious amber was finally formed. Back to the influence of the flood events in the Kani period, many animals and plants have already adapted to the arid climate, and as a result, the short-term wet period has caused them to be unable to adapt to changes and thus go extinct.

How did dinosaurs ascend to the throne with the help of the flood in Carney's time?

Before the Canyon flood, dinosaurs were only one of several creatures in nature, and they were not excellent. Many species in the earth's biosphere were eliminated because they could not adapt to the changes of climate and environment, thus leaving a large number of niches. According to archaeological findings, one of the reasons why dinosaurs could not dominate nature in the early days was that they had natural enemies in nature, and later this natural enemy disappeared after the Kani flood.

Since then, dinosaurs have developed as quickly as they opened the shackles, and the footprints of the population have gradually spread from a single area of the mainland to the whole continent. Even today's Antarctic continent may have dinosaur fossils. Other species that rose at the same time as dinosaurs were turtles, lizards and marine mammals. The expansion of dinosaur population occurred not only on land, but also in the ocean. The flood events in the Carney period led to large-scale acidification of the ocean, which led to the extinction of a large number of marine invertebrates.

You may think that these situations are speculated by geologists and archaeologists, but in fact these speculations are based. Geologists have discovered two kinds of sedimentary rocks in different periods in the southern Alps because their geographical characteristics are completely different. One of the sedimentary rocks is relatively dry, so it appeared before the flood event, and geologists have not found traces of dinosaurs in the sedimentary rocks. Another sedimentary rock has traces of carbonate deposition, indicating that it was formed after the flood event.

In the sedimentary rocks of the latter, scientists actually found dinosaur footprints, which can explain that dinosaurs did not expand before the flood event, but the population expanded after the flood event.

How did dinosaurs decline after that?

The Canyon flood lasted for 2 million years, which is equivalent to giving dinosaurs 2 million years of development time. Dinosaurs lived up to the expectations of nature, survived the flood, and developed rapidly in the next 6.5438 billion years, gradually becoming the overlord of the earth's ecological circle. However, no species can dominate the biosphere forever. After ruling for more than 100 million years, dinosaurs finally disappeared in the mass extinction event 65 million years ago.

So what happened in this recent extinction, which not only made dinosaurs lose their throne, but also disappeared from the earth? This problem has been studied and discussed in academic circles for a long time, and there are several hypotheses at present. The first hypothesis is that the earth was suddenly hit by an asteroid 65 million years ago, which triggered a large-scale natural disaster and then led to a global climate disaster. This hypothesis has been recognized to the highest degree, because scientists have found craters in Mexico's Yucatan Peninsula that meet this hypothesis.

The impact of asteroids can not directly cause global extinction, and then a series of natural disasters, such as volcanic eruptions and tsunamis, lead to the extinction of land and marine life together. The second hypothesis holds that a highly contagious and deadly virus appeared on the earth 65 million years ago. This virus can infect not only terrestrial organisms, but also marine organisms. Finally, more than 90% of the creatures on the earth are "one pot".

The third hypothesis holds that there was indeed climate cooling on the earth at that time, but it was not caused by a large-scale volcanic eruption, but the solar activity entered a low tide period, which led to a significant reduction in the heat transferred from the sun to the earth. Compared with the second and third hypotheses, the first hypothesis is more accepted because there is more evidence to support it.

What does the rise and fall of dinosaurs show?

The prosperity of dinosaurs originated from the drastic change of natural climate, and the decline was also due to the drastic change of natural climate, which shows that any life on earth is weak in front of nature, and as long as the climate changes drastically, it is easy to threaten the survival of species. In short, the role of natural selection is greater than the efforts of species. Only creatures that adapt to natural changes have a chance to survive, and those that cannot adapt to changes are doomed to be eliminated.

The same is true of human beings. The natural law of "natural selection, survival of the fittest" has never changed. Perhaps most people will disagree with this view and think that we can't put humans and dinosaurs together, because human beings have developed civilization, with the blessing of science and technology, and have the ability to cope with changes in the natural climate and environment. Is that really the case? If human beings really have the ability, climate warming will not become more serious, and the development trend is still deteriorating.

On the surface, the mass extinction event led to the extinction of many creatures and the destruction of life on earth. This scene is very tragic. On the other hand, mass extinction is a link in the self-circulation of nature, and all unsuitable creatures will be eliminated.