The largest species extinction in the history of the earth Occurred approximately 252 million years ago It is faster in the ocean, but lasts 10 times longer on the surface of the earth.
This is reflected in a new study prepared by 23 researchers and published in the journal this Monday “Proceedings of the National Academy of Sciences.” This work focuses on “Great death” or “great death”, It happened 252 million years ago, and it was so dramatic and widely distributed that it wiped out more than 95% of marine species and 70% of terrestrial species.
Some previous studies have shown that this is due to climate change Heat released by intrusive igneous rocks caused by large-scale volcanic eruptions in Siberia. Then came the age of dinosaurs.
“People think that because the ocean is extinct within a short period of time, life on land should follow the same pattern, but we found that the ocean is extinct In fact, this may be the point in time of a longer land event”, Said Pia Viglietti, a postdoctoral researcher at the Field Museum in Chicago.
Ken Angielczyk, senior writer and curator of vertebrate paleontology at the Field Museum, added: “This article is the first to really focus on vertebrates. He said: “No, what is happening is unique to the earthly kingdom.”
Underwater creatures have a more complete fossil record, and the corpse is quickly covered by sediment. Therefore, paleontologists have long known that the mass extinction occurred at the end of the Permian period about 252 million years ago. In about 100,000 years, 95% of marine species have become extinct.
Although it looks like a long time, This is not the case from a geological point of view. During the 3.8 billion years of life on Earth, the ocean extinction at the end of the Permian lasted for 100,000 years, which is equivalent to 14 minutes in a year.
In order to understand life on land, Viglietti, Angielczyk and their colleagues conducted a survey Fossils of 588 quadrupeds He lived on the Karoo Plateau in South Africa at the time of the Permian extinction.
Zaituna Skosan, the Paleontology Collection Manager of the South African Museum, said: “The area where we found fossils in this study is very beautiful. The green hillsides are so inviting on a refreshing summer morning that the heat is unbearable.” and this article One of the authors.
The researchers created a database, separated the fossils by age, and grouped the specimens at intervals of 300,000 years.This method allows them to quantify The emergence and disappearance of different species And look at the wider life over time, rather than relying on a single specimen to tell the whole story.
Roger Benson, professor of paleontology at Oxford University in the United Kingdom, pointed out that the research team used statistical data to find the research team. Extinction model based on hundreds of fossils. “When a species disappears, it may be extinct, or it may be there, waiting to be discovered, but it has not been discovered so far.”
One of the species that helped reveal the pattern of extinction and recovery is “Qulong”, Herbivorous relatives of early mammals Depending on the breed, its size will vary from puppy to cow. Viglietti emphasized: “It has a beak and fangs, it is not the most attractive animal, but I have a soft spot for’Lystrosaurus’ because it is the first animal I studied as a graduate student.”
“We saw that the’Dragon Dragon’ appeared before the extinction began, and it was already very rich. Let us think about what drives this richness, if the “tyrannosaurus” just occupied the barren land after the extinction of other animals The land, or environment, is changing, and the “Tyrannosaurus” has adapted to these changes that led to the extinction of all other species. Our best guess is the latter”, Point out Vigletti.
Research on fossils (Lystrosaurus) and other fossils shows that researchers have found that the Permian extinction looks completely different on land than on the ocean and lasts longer.If the life history on the earth is compressed into one year, and the extinction at the end of the Permian killed 95% of marine animals in 14 minutes, the extinction of the earth will take about 10 times longer, which is about Two hours and twenty minutes.
It is not clear why mass extinctions occur much more slowly on land. “Earth climate change is cumulative They add up over time. Viglietti said that the ecosystem was slowly destroyed, and then to the point where everything collapsed.