By Kaylee Hayes | Reporter
A research effort led by New Mexico State University paleontologist Dr. Andrew Flynn and Baylor geosciences professor Dr. Daniel Peppe has solved one of vertebrate paleontology’s longest-running debates.
The study, recently published in Science Magazine, reveals that dinosaurs were thriving right up until the Chicxulub meteor struck Earth, challenging the longstanding notion that dinosaurs were already declining in population during the end of the Cretaceous period.
“The dinosaurs weren’t declining; they were doing really well,” Peppe said. “If not for this meteor impact, they likely wouldn’t have gone extinct.”
The research focuses on layers of rock in northwestern New Mexico’s San Juan Basin. The Naashoibito Member has been described as a problematic site in the past because it has been difficult to date, Peppe explained.
Flynn explains the concept of magnetic stratigraphy, which is a geophysics-based practice that examines the Earth’s magnetic field, and how it has been recorded in rocks.
Through this and radiometric dating, they came to the realization that the fossils found in the Naashoibito Member are younger than once thought, meaning the dinosaurs were alive right up until the impact.
“It’s an incredible natural laboratory,” Peppe said. “You can study how plants, mammals and dinosaurs responded to the most catastrophic event in Earth’s history.”
Although currently at New Mexico State University, Flynn began the project while earning his doctorate at Baylor and was one of Peppe’s first students, he said.
Peppe said the research was an interdisciplinary collaboration, eventually leading to constructing the timeline and finally publishing the paper.
“We have people that are dinosaur paleontologists and people that are mammal paleontologists and modern ecologists,” Peppe said. “In our lab, we study fossil plants and Earth’s magnetic field, and so combining all that together is how we were able to come to this conclusion.”
Several past Baylor geosciences graduate students contributed to the project, including Dr. Caitlin Leslie, Dr. Adam Davis and Dr. Will Fenley.
“It was a long-term project with lots of Baylor people,” Flynn said. “The collaborative nature of it is what made it special.”
Peppe credited Flynn for the grunt work of analyzing the years of data found and held at Baylor through this 16-year partnership.
“Andrew is the one who really finally put it all together and pushed it across the finish line,” Peppe said. “It was definitely worth the time.”
Baylor geosciences Ph.D. candidate Dava Butler, who studies Ice Age mammals, said the research has been noted by dinosaur researcher Dr. Thomas Holtz, a principal lecturer in the University of Maryland’s department of geology.
“It’s a huge accomplishment for our paleontology group,” Butler said. “It’s the kind of work that reminds you why research matters.”
The study’s conclusion is clear: dinosaurs weren’t doomed until the impact of the Chicxulub meteor.
“Dinosaurs existed on Earth for more than 150 million years,” Peppe said. “They were resilient, diverse and successful until a random cosmic event changed everything.”
