Sixty-six million years ago, a meteor struck Earth just off the coast of Mexico's Yucatán Peninsula. Dinosaurs and 75 percent of the species on the planet went extinct – but what happened to the flora and fauna that survived?
Scientists from the University of Wyoming (UW) are part of an interdisciplinary team working to answer that exact question. Using clues from the fossil record, the researchers are traveling back in time to better understand how life rebounded after such a cataclysmic event.
Dr. Ellen Currano, a UW paleobotanists professor, focuses on plant fossils. Because plants are at the bottom of the food chain, she said their story can help scientists understand what happened to other organisms in the mass extinction event.
“Dust and yucky stuff was kicked up into the atmosphere blocking sunlight, creating a big extinction of the plants and then a big extinction of everything that relied on the plants,” she said.
In addition to illuminating what happened in the aftermath of the meteor strike, Dr. Currano said the study can also help paint a picture about why modern-day plants are the way they are in the present.
“Today we have 350,000 species of plants – after insects, this is the most diverse group of organisms on the planet,” she said. “This event was a big game changer in setting us up toward why we see the plants outside that we do today.”
The team of scientists are focusing on two sites – the Denver Basin in Colorado and the Williston Basin in North Dakota. In those locations, the fossils provide a clear record of what happened before and after the meteor impact.
However, interpreting that record requires a big team of people with many skill sets. While Dr. Currano is focused on plant fossils in the study, she said there’s a lot more to explore to get the full picture.
“We have folks studying dinosaurs, folks studying mammals and turtles and crocodiles, and then we have folks who look at chemical signals in the rocks,” she said. “Those can help us understand what the climate and other aspects of the environment were in that million years after the impact event.”
Dr. Currano said that while the two sites have already been the subject of many studies, this project is collecting data using new chemical-focused techniques that can put more precise numbers on the speed of recovery post-meteor strike.
“There was kind of this fudge-y, ‘Oh, you know, it took a few million years for things to happen,’ and with these locations, we think we can get at ‘10,000 years after impact, here is what this place looks like, here’s what it looked like 50,000 years after,’” she said.
To Dr. Currano, the study can help humans better understand current mass extinction events and habitat loss connected to climate change. While today’s changes are happening at a slower pace than the dinosaur-extinction meteor strike she said they’re also happening at a faster pace than many other shifts in life on Earth.
“Sometimes I like to tell my students that humans are like a meteor impact… if we look at a lot of the other big changes in Earth's history and extinction events, they're not as rapid as what people are doing,” she said.
The collaborative five-year study is led by the Denver Museum of Nature & Science and is funded by a nearly $3 million grant from the National Science Foundation.
The study is supported by multiple universities and research institutions around the country, including the University of Oregon, UC Boulder, and the Smithsonian National Museum of Natural History.
