First oxygen starvation-related mass extinction 550 million years ago

First oxygen starvation-related mass extinction 550 million years ago

Impressions of the Ediacaran fossils Dickinsonian (middle) with the smaller anchor shape Parvancorina (left) in Ediacaran member sandstone from Nilpena-Ediacara National Park in South Australia. | Credit: Virginia Tech/Scott Evans

Mass extinctions have been shown to be the force that keeps the wheel of evolution turning. Scientists have now found the cause of the first known mass extinction some 550 million years ago.

Virginia Tech geobiologists have found that the earliest known mass extinction event was caused by the declining availability of oxygen, resulting in the loss of 80% of the animals that lived during the Ediacaran period. The Ediacaran Period spanned almost 96 million years, followed by the Cryogenic Period 635 million years ago and followed by the Cambrian Period 539 million years ago.

The paper, published in Proceedings of the National Academy of Scienceexplained that although the study doesn’t point to the actual cause of the mass extinction, analysis of the data scientists have collected shows that animals that depended heavily on oxygen to survive weren’t faring well.

“Those whose body plans and behaviors indicate they were dependent on significant amounts of oxygen appear to have been hit particularly hard,” said Scott Evans, a postdoctoral fellow at Virginia Tech and the study’s lead author, in a press release.

“This suggests that the extinctions were controlled by the environment, as were all other mass extinctions in the geological record,” he added.

Imprints of the Ediacaran fossils Dickinsonia (left) and the related but rare form Andiva (right) in the sandstone of the Ediacaran member from Nilpena-Ediacara National Park in South Australia.

Impressions of the Ediacaran fossils Dickinsonian left) and related but rare form Andiva (right) in Ediacaran Member sandstone from Nilpena-Ediacara National Park in South Australia. | Credit: Virginia Tech/Scott Evans

Scientists cannot attribute the decline in oxygen levels around the world to any specific event. It could be due to a number of phenomena, including volcanic eruptions, tectonic plate movements, asteroid impacts, or a combination of these.

“What we’re seeing is that the extinct animals appear to be responding to reduced global oxygen availability,” Mr Evans said.

“Environmental changes such as global warming and oxygen deprivation may lead to massive animal extinctions and profound ecosystem disruption and restructuring,” said Shuhai Xiao, co-author of the study.

Highlighting the types of animals that existed during this period, Mr Evans said they looked “strange” and pointed out that they were so early in the evolutionary process that they “were experimenting with different ways, large ones, sometimes mobile.” to build animals, multicellular bodies.”

“There are many ways to recreate their appearance, but the takeaway is that the fossils we find before this extinction often don’t fit well with the way we classify animals today. In essence, these extinctions may have helped pave the way for the evolution of animals as we know them,” he added.

Climate change warning

The study comes at a time when freshwater bodies are exhibiting anoxia, or reduced capacity to uptake oxygen, caused by global warming due to climate change and pollutant runoff.

“Our study shows that this new, first-ever mass extinction of animals, like all other mass extinctions in Earth’s past, was caused by major climate change — another in a long list of cautionary tales highlighting the dangers of our current climate crisis to animal life show,” Mr Evans said.

There are five major mass extinction events, the “Big Five,” that have shaped animal evolution – the Ordovician-Silurian extinction (440 million years ago), the Late Devonian (370 million years ago), the Permian and Permian extinctions in the Triassic (250 million years ago), the Triassic-Jurassic (200 million years ago) and the last Cretaceous-Paleogene (65 million years ago).

#oxygen #starvationrelated #mass #extinction #million #years

Leave a Comment

Your email address will not be published. Required fields are marked *