Life recovered not long after the asteroid killed the dinosaurs

Not long after the asteroid that wiped out the dinosaurs struck 66 million years ago, its crater was soon teeming with life, according to a new study.

The Cretaceous-Tertiary extinction event eliminated 75 percent of life on Earth, including all non-flying dinosaurs.

After the extinction, it was believed that the rate of recovery at sites closest to where the asteroid hit was much slower due to environmental contaminants like toxic metals released after impact.

However, researchers from the University of Texas, Austin found the exact opposite to be true in a new study examining core samples. Less than a decade after the asteroid hit, the crater was home to microorganisms, and within 30,000 years, a thriving ecosystem.

The study was published in the journal Nature and the results suggest that recovery after major catastrophic events are influenced by local factors.

“We found life in the crater within a few years of impact, which is really fast, surprisingly fast,” said Chris Lowery, the leader of the research. “It shows that there’s not a lot of predictability of recovery in general.”

Extracted during a 2016 expedition, the core section used in the study showed the researchers a detailed map of life in the crater from impact to thousands of years after. The researchers had 130 meters of material to analyze.

A few years after the asteroid hit, the core samples showed microorganisms inhabited the area, and 30,000 years later, the crater was home to an entire ecosystem.

The presence of microfossils in the crater led the researchers to theorize that the area was also a habitat for larger species later on down the line.

“Microfossils let you get at this complete community picture of what’s going on,” said Lowery. “You get a chunk of rock and there’s thousands of microfossils there, so we can look at changes in the population with a really high degree of confidence … and we can use that as kind of a proxy for the larger scale organisms.”

While the area close to the crater was recovering at a remarkable rate, the researchers also found that other regions around the world took up to 300,000 years to similarly recover.

The study has promising implications in examining recovery rates worldwide, particularly from potential climate change-triggered events.

Local factors such as water circulation and interactions between organisms have the most influence on an area or ecosystem’s potential to recover, according to the results.  

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By Kay Vandette, Earth.com Staff Writer

Original art by John Maisano, University of Texas Jackson School of Geosciences