UT fossil study challenges theory about ‘The Great Dying’

Katy Nelson, News Reporter

This article first appeared in the Feb. 11, 2022 flipbook.

A study by UT researchers challenges a traditional theory that an ocean acidification event known as “The Great Dying” killed most animals living underwater. The research team studied a collection of fossil shells and determined ocean acidification may not have caused the extinction of marine animals.

“The Great Dying,” also known as the Permian Extinction, occurred 250 million years ago and is considered the greatest mass extinction event in the last 500 million years, resulting in the death of “96% of all marine species and up to 70% of terrestrial vertebrates,” according to World Atlas. Conventional theories suggest ocean acidification — increased carbon dioxide levels lowering the pH of the ocean and making the water more acidic — was the cause of “The Great Dying.” 

However, researcher William Foster said the team found that the acidification levels did not kill the marine animals. Instead, volcanic eruptions wiped out a large amount of marine life at the time, according to researcher Rowan Martindale. 

“One of the questions we want to know today, that’s in the news all the time, is, ‘How is a new climate crisis going to play out in our lives?’” said Foster, a former postdoctoral fellow at the University. “One way we can answer that question is to look at the past.”

Foster, who is now an Emmy Noether research group leader at the University of Hamburg, said the researchers believe ocean acidification happened during a different time period, possibly during the Paleocene-Eocene Thermal Maximum.

“We need to think of new ways to investigate this question,” Foster said. “We’re so convinced that their computer models are right that ocean acidification must have happened in the past at some point,” Foster said. 

Martindale said it is important to question long-standing beliefs as a scientist.  

“That’s how we do science,” Martindale said. “It’s how we understand the past Earth better as we propose a hypothesis. And then, … we see if we can refute it, we see if we can support it.”

Foster said he hopes that with their research bringing attention to ocean acidification, other scientists will consider the rising temperatures in oceans today.

“Quite often you hear scientists say, ‘It doesn’t matter how bad things get today, it will never be as bad as the Permian,’” Foster said. “But if our data is showing that what’s happening today is happening much more rapid(ly) and could be as catastrophic as the Permian, … we need to start taking that seriously.”