Earth saw its sixth mass extinction 260 million years ago, new research proposes

tech2 News Staff

We have heard experts say we are currently in the sixth mass extinction, however, that number might soon change.

New research has found that a sixth extinction-level event has already taken place, around 260 million years ago. This was previously thought to be a minor extinction event but it was severely underestimated.

This makes the current event, the one we are going through, the seventh.

The previous event has been named as the end of the Guadalupian era or the Middle Permian period.

An ancient mass extinction called the Great Dying wiped out 90% of all life on earth. Image: Earth Archives

An ancient mass extinction called the Great Dying wiped out 90 percent of all life on earth. Image: Earth Archives

Michael Rampino, co-author of the study said in an interview with Newsweek, "The end-Guadalupian event was somewhat selective. Coral reef environments were very hard hit. Ocean bottom communities, and swimming organisms such as coiled ammonoids, were hard hit. On land, many reptile species disappeared. So the event was severe, both in the number of species going extinct and in the major ecological damage."

According to available data, around 60 percent of the marine species became extinct and Rampino said that the same amount of non-marine species might have died out as well.

The study states the grim reality of that event by saying, "In terms of both losses in the number of species and overall ecological damage, the end-Guadalupian event now ranks as major mass extinction, similar to the other five."

The Guadalupian extinction has something in common with the other five. Rampino, in a statement, said, "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."

In the case of the end-Guadalupian extinction event, the Emeishan flood-basalt eruption produced the Emeishan Traps. It is an extensive volcanic rock formation, found today in south-western China in the Sichuan province. The eruption's impact was similar to those caused in other known major mass extinctions.

Rampino said in a statement, "Massive eruptions such as this one release large amounts of greenhouse gases, specifically carbon dioxide and methane, that cause severe global warming, with warm, oxygen-poor oceans that are not conducive to marine life."

It is important to study past events. In a statement, Rampino said, "It is crucial that we know the number of severe mass extinctions and their timing in order to investigate their causes."

The previous five mass extinction events are:

  • The end of the Ordovician (443 million years ago)
  • The Late Devonian (372 million years ago)
  • The Permian (252 million years ago)
  • The Triassic (201 million years ago)
  • The Cretaceous (66 million years ago)

The seventh mass extinction is already underway and scientists say "It could end up being as severe as these past events." We are seeing a rise in temperatures due to climate change. A UN report stated that one million species have already become extinct due to rapidly changing weather conditions, deforestation and warming of the oceans. The animals that are not extinct already are endangered due to man-made situations or because they are not able to adapt to the above-mentioned changes.

Water expands when it is heated and the warming sea is rising. Melting glaciers are also adding to the risings water levels.

The findings from this study have been published in the journal Historical Biology. The authors of this study include researchers from the New York University, USA and Nanjing University. China.

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