First mass extinction of animals happened 550 million years ago: Study

Geologists in the United States have shed new light on the first known mass extinction event on Earth, which occurred 550 million years ago during the period known as the Ediacaran, according to details of a new study published by . Science Alert. The study was conducted by the Virginia Tech College of Science and led by Scott Evans, a postdoctoral researcher in the Department of Geosciences. The study shows that the earliest known mass extinction of about 80% of the animals occurred during this time period.

“This included the loss of many different types of animals; however, those whose body plan and behavior indicate they were dependent on significant amounts of oxygen were hit particularly hard,” said Mr. Evans. . “This suggests that the extinction event was environmentally controlled, as are all other mass extinctions in the geologic record.”

According to Virginia Tech, Mr Evans’ work was published on 7 November in the Proceedings of the National Academy of Sciences, a peer-reviewed journal of the National Academy of Sciences. Study co-authors were Shuhai Xiao, also a professor in the Department of Geology, and several researchers led by Mary Droser from the Department of Earth and Planetary Sciences at the University of California, Riverside, where Mr. Evans earned his master’s degree and PhD. .

“Environmental changes, such as global warming and deoxygenation events, can lead to mass extinctions of animals and profound disruption and restructuring of ecosystems,” said Shuhai Xiao, who is part of the Global Change Center, Virginia Tech. Is. Fralin Life Sciences Institute. “This has been demonstrated repeatedly in studies of Earth history, including this work on the first extinctions documented in the fossil record. Thus this study informs us about the long-term impact of current environmental changes on the biosphere. “

According to Xiao, there are five known mass extinctions in animal history, the “Big Five”, including the Ordovician–Silurian extinction (440 million years ago), the late Devonian extinction (370 million years ago). The Virginia Tech College of Science said in the release that the Permian–Triassic extinction (250 million years ago), the Triassic–Jurassic extinction (200 million years ago), and the Cretaceous–Paleogene extinction (65 million years ago).

Mr Evans and his colleagues compiled data on rare fossils of the squishier type of animal from around the world that date back to the Ediacaran. They found that the sudden change in biodiversity that had been previously detected was not simply the result of sampling biases.

“Our study shows that, as with all other mass extinctions in Earth’s past, this new, first mass extinction of animals was caused by major climate change, which is very important for animal life in our current climate. was another in a long list of cautionary tales demonstrating the dangers of the crisis,” Evans said.