How long does the land need to “rest and recuperate” after the earth’s life has been “destroyed”? 10 million years! Chinese and British paleontologists spent 10 years studying the largest biological extinction event in Earth’s history, and finally found that 10 million years after the mass extinction, lakes, forests and other terrestrial ecosystems were significantly restored.
There have been five biological extinction events in the history of the known Earth. The mass extinction of the late Pleistocet, which occurred 252 million years ago, was the largest. The mass extinction has led to the rapid extinction of more than 80 per cent of marine life and 75 per cent of terrestrial life. Since then, the Earth has evolved into modern biota that have continued to this day.
This time, an international team led by the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences conducted a systematic study of sedimentary formations after the end of the Ordos Basin in China. Through high-precision dating and a series of stratigraphy and palaeontology studies, the team found that by about 242 million years ago, lakes and forest ecosystems had been restored and complex food networks had re-emerged.
Researchers found rich fossils of plants, mesozoics, aphids, insects, fish and fish manure in sedimentary formations. Among them, the largest spiral fish dung fossils up to 77 mm, indicating that there was a large roila than predatory fish. In some of the fish dung fossils, researchers also found the remains of the twin-winged insects. This is direct evidence that fish feed insect larvae, suggesting that there was a “algae-insect-fish-large predatory fish” predation chain.
“Combined with the emergence of coal fossils in the same period, we judge that 10 million years after the mass extinction at the end of the Second Century, terrestrial life has returned from barrenness to prosperity. Within 10 million years, the earth is likely to remain in general depression because of its unstable environment and persistent high temperatures and droughts. Wang Bo, a researcher at the Nangu Institute of the Chinese Academy of Sciences who led the study, said.
The results were published in the internationally renowned geosciencejournal Geology at the end of March.