First Adult T. rex Trackway Discovered in North Dakota Badlands

Scientists have unearthed the first-ever trackway produced by a fully grown Tyrannosaurus rex in the badlands of southwestern North Dakota, near the Montana border. The discovery, detailed in a paper published this week in the Journal of Vertebrate Paleontology, marks a significant milestone in paleontology, as only two isolated adult T. rex footprints had previously been confirmed globally—in New Mexico and Montana—neither of which revealed how the animal moved.

Dr. Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science, emphasized the rarity of the find. “Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior,” Lyson said. “With a trackway, we can actually follow an animal as it moved across the landscape. That is incredibly rare for T. rex.”

The trackway was discovered in 2025 on U.S. Forest Service land near Marmarth by Kent Hups, a high school teacher and amateur fossil hunter volunteering on one of Lyson’s excavation teams. The site spans approximately 23 feet and contains four three-toed prints, each roughly 3 feet long. Based on the spacing between the impressions, researchers calculated that the massive creature, which weighed over seven tons, was walking at speeds between 3.5 and 4.5 miles per hour.

Experts attributed the tracks to T. rex based on their dimensions, morphology, and the abundance of tyrannosaur remains in the area, including the juvenile fossil nicknamed “Teen Rex,” found by three boys in 2022. The tracks date back approximately 66.5 million years, placing them at the very end of the Cretaceous period, just before the asteroid impact that led to the extinction of the dinosaurs.

Peter Falkingham of Liverpool John Moores University in England served as the lead author of the study. He analyzed 3D scans of the site conducted by Denver Museum researchers and authored the paper without visiting North Dakota. Three of the four footprints are scheduled to be airlifted by helicopter this fall and transported to the Denver Museum of Nature & Science for further study and display.

“As a teacher, I’m always telling my students that science starts with curiosity, passion and careful observation,” Hups said regarding his role in the discovery. “I never imagined that could lead me to a discovery like this.”