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The extinction of the dinosaurs is still behind the event "The Great Dying": the deadliest tragedy in the history of the earth.
Tác giả: HyHy
In Earth's history, several mass extinction events have destroyed ecosystems, including one that famously wiped out the dinosaurs. But none of them are as devastating as "The Great Dying," which took place 252 million years ago in the late Permian.
A new study has detailed how life recovered from the aforementioned mass extinction event. The international research team - which includes researchers from China University of Geosciences, California Academy of Sciences, University of Bristol, Missouri University of Science and Technology, and Chinese Academy of Sciences - times first shows that the Permian at the end of the mass extinction was much more extreme than other events, because diversity was severely collapsed.
To better describe "The Great Dying," the team sought to understand why populations of organisms 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 was much more severe than any mass extinction: it caused 95% of life on Earth's land, oceans and air to disappear. lost. Completely lost. With the survival of only 5% of species, ecosystems were destroyed, and this meant that ecological communities had to regroup from scratch.
To investigate, lead author and researcher Yuangeng Huang, now of China University of Geosciences, Wuhan, reconstructed food webs for a series of 14 life combinations spanning the Permian and Triassic period. These assemblages are sampled from northern China, providing a snapshot of how a region of Earth responds to crises. "By studying fossils and evidence from their teeth, stomachs and feces, we were able to determine which species were predators and which were their food," Huang said. The most important thing is to build the correct food web so that we can understand how that ecosystem works. "
The food web is made up of plants, mollusks, insects that live in ponds and rivers, as well as fish, amphibians, and the reptiles that feed on them. Reptiles ranged in size from modern lizards to herbivores weighing half a ton with small heads, giant barrel-shaped bodies, and thick bony scales covering their bodies.
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. penetrate the thick skin of another animal. When these animals died in the late Permian mass extinction, the ecosystem was out of balance for ten million years. Later, other living dinosaurs and mammals began to evolve during the Triassic. The first dinosaurs were quite small - bipedal insectivores about a meter long, but they quickly became larger and more diverse.
Peter Roopnarine, Director of the Institute of Geology said: “Yuangeng Huang spent a year in my laboratory. He applied ecological modeling methods that allowed us to look at ancient food webs and determine how stable or unstable they were. This model will essentially disrupt the food web, remove species, and test overall stability.”
Professor Mike Benton from the University of Bristol said: “We found that the late Permian event was special in two ways. First, the collapse in diversity was much more severe than in other mass extinctions, which had low-stability ecosystems before collapsing around the end of the mass extinction. . And second, it takes a very long time for ecosystems to recover, maybe 10 million years or more, while in other mass extinctions, ecosystem recovery times are fast. more".
Finally, characterization of biological communities, especially those that have been successfully restored, provides valuable insights into how modern species may have evolved as humans pushed the Earth. to the next mass extinction.
"This is an amazing new result," said Professor Zhong Qiang Chen of China University of Geosciences, Wuhan. Until now, we were able to describe food webs in ecosystems, but we were not able to test their stability. The combination of new data from long stretches of rock in North China with advanced computational methods allows us to study food webs in the modern world."