Scientists at China's Nanjing University are believed to have discovered a sixth mass extinction event that took place on Earth 260 million years ago that has remained unknown until now, the Daily Mail reported.
It was previously believed that our planet had experienced only five geological periods featuring mass extinctions, namely the Ordovician, the Late Devonian, the Permian, the Triassic, and the Cretaceous. The first one was believed to have taken place around 540 million years ago, destroying 85% of animal species, which were mostly living in the sea at the time.
However, the most recent and well-known one is often blamed for killing 75% of life on the planet and wiping out the dinosaurs, with a massive asteroid crashing into the Earth 66 million years ago.
The new findings, on the other hand, suggest that another mass extinction was caused by a volcanic eruption that could have taken place in southern Asia during the Middle Permian period, thus potentially raising the number of extinction events in the geological record.
“It is crucial that we know the number of severe mass extinctions and their timing in order to investigate their causes”, a professor at New York University's Department of Biology, Michael Rampino, wrote in the journal Historical Biology.
“Notably, all six major mass extinctions are correlated with devastating environmental upheavals—specifically, massive flood-basalt eruptions, each covering more than a million square kilometres with thick lava flows”.
Rampino also noted that massive eruptions, such as the recently discovered one, could release a large amount of greenhouse gases, specifically carbon dioxide and methane, resulting in severe global warming.
Scientists believe that the eruption was also a reason for the creation of a dramatic rock formation in southern China known as the Emeishan Traps.