It takes 10 million years for life on Earth to recover from “The Great Dying”.

In the history of the Earth, a number of mass extinction events destroyed ecosystems, including one well-known that wiped out dinosaurs. But of these, there is no such dire event as “The Great Dying”, which took place 252 million years ago in the late Permian period. A recent study has revealed details about how life recovered from the aforementioned major extinction. The international team – consisting of researchers from China University of Geosciences, California Academy of Sciences, Bristol University, Missouri University of Science and Technology, and Chinese Academy of Sciences – times the first shows that the Permian period at the end of the mass extinction was much more severe than in other events, as diversity collapsed.

To describe “The Great Dying” more, the team sought to find out why biological populations did not recover as quickly as other mass extinctions. The main reason is that the “crisis” that took place at the end of the Permian period is much more severe than any mass extinction: it causes 95% of Earth’s land, ocean and air life to disappear. completely lost. With the existence of only 5% of the species, ecosystems were destroyed, and this meant that ecological communities had to regroup from the beginning.

To investigate, lead author and researcher Yuangeng Huang, currently working at the Chinese University of Geosciences, Wuhan, recreated the food web for a series of 14 life combinations spanning from Permian and Triassic. These collections, sampled from northern China, provide a quick picture of how an area on Earth reacts to crises. “By studying the fossils and the evidence from their teeth, stomach contents and feces, we can determine which species are predators and which are their food. The most important thing is to build a correct food web so that we can understand how that ecosystem works.“.

Food nets are made up of plants, mollusks, insects that live in ponds and rivers, as well as fish, amphibians and reptiles that eat them. Reptiles range in size from modern lizards to half a ton herbivores with a small head, a giant barrel-like body and thick bony scales covering the outside.

The saber-toothed gorgonopsia of this era were wandering predators, some of them as large and powerful as modern lions and possessing long fangs as their name suggests. pierce the thick skin of other animals. When these animals died out in the late Permian mass extinction, the ecosystem was out of balance for ten million years. Later, living dinosaurs and other mammals began to evolve during the Triassic. The first dinosaurs were quite small in size – bipedal insectivores were about a meter long, but they quickly became larger and more diverse.

Peter Roopnarine, Director of the Geological Institute said: “Yuangeng Huang spent a year in my laboratory. He applied ecological modeling methods that allowed us to examine ancient food webs and determine their degree of stability or instability. Basically, this model would break the food net, remove the species and check for overall stability“.

Professor Mike Benton from the University of Bristol said: “We found that the Late Permian event was special in two ways. First, diversity collapse is much more severe than other mass extinctions, having already had low stability ecosystems before collapsing around the end of the great extinction. . And second, it takes a very long time for ecosystems to recover, maybe 10 million years or more, while in other major extinctions, ecosystem recovery times take place rapidly. more”.

Finally, characterizing biological communities, especially those that have successfully recovered, provides valuable insights into how modern species can thrive as humans push the Earth. to the next great extinction.

Professor Zhong Qiang Chen of China University of Geosciences, Wuhan, said: “This is an astonishing new result. Until now, we can describe food nets in ecosystems, but we cannot test their stability. The combination of new data from long rocks in North China with advanced computational methods allows us to study food webs in the modern world.“.