Approximately 252 million years ago, 95 percent of all life on Earth was destroyed in what was the largest mass extinction in Earth’s history. But not long after, there was a sudden surge of reptilian diversity that coursed throughout the land, in the oceans, and in the skies.
After receiving a five-year Faculty Early CAREER Development Program award totaling $622,222 from the National Science Foundation, Sterling Nesbitt, an associate professor of geobiology in the Department of Geosciences in the College of Science, and a team of researchers are gearing up for a new field project to learn more about how extinction events — and time itself — drive evolution in vertebrate communities.
“Do communities persist for millions of years? Are the communities that we see outside our very windows always in this state of change or are they pretty stable and it takes a lot of pushing from a natural disaster to move them to a new state?,” asks Nesbitt, an affiliated faculty member of the Fralin Life Sciences Institute and the Global Change Center.
To answer these questions, Nesbitt has chosen to explore a critical time in Earth’s history: the Triassic Period. This time period faced a multitude of catastrophic events, but it was also during this time when key groups of present-day vertebrates — including mammals, turtles, lissamphibians, and squamates — originated.
Nesbitt and his team will focus their efforts on the Petrified Forest National Park. Located in northeastern Arizona, the park is renowned for its giant fossilized trees that date back to the Late Triassic period. Among the trees, paleontologists have found entire fossil communities that have lasted for at least 15 to 20 million years, making this the perfect place to find fossils for their research.
With a team of undergraduate and graduate students, and fellow faculty, Nesbitt will be excavating new fossils from areas within and around Petrified Forest National Park. In addition to collecting new data, the team will visit museums and institutions that already have information from this area, such as the University of California, Berkeley and the American Museum of Natural History.
“As paleontologists, our work is almost detective-like, and our hypotheses about how animals lived and interacted can only be based on the fossils, and therefore, the data we collect,” said Michelle Stocker, an assistant professor of geobiology in the Department of Geosciences, and also an affiliated faculty member of the Fralin Life Sciences Institute and the Global Change Center.
“By focusing on the interconnectivity of these precise locations and time periods, and collecting both large and small fossil remains, we will be able to construct a much richer and more accurate idea of the types or lack of changes that occurred during the Triassic,” Stocker added.
The team will also conduct an extension of the Discoveries in Geosciences (DIG) Field School, a K-12 education program created by University of Washington, which brings STEM teachers out to Petrified Forest National Park, where they work alongside researchers. Then they can apply what they have learned to paleontology-related activities in the classroom.
Most teachers from the original program represent the northwestern United States. In an effort to increase diversity, the team will be recruiting teachers from the southeastern United States and Native American groups throughout the southwest, specifically the Zuni and the Navajo Nesbitt said.
“Our hypothesis is that the communities are actually really similar for a really long period of time. In the Triassic, it was essentially the same community again and again but with slightly different species. They looked really similar and probably had similar ecological roles,” said Nesbitt.
-Written by Kendall Daniels of the Fralin Life Sciences Institute.