First adult Tyrannosaurus rex trackway uncovered in North Dakota

Paleontologists have documented a four-footprint trackway attributed to a full-grown Tyrannosaurus rex in the badlands of southwestern North Dakota, near the Montana border. The discovery, reported in the Journal of Vertebrate Paleontology, follows only two previously confirmed adult T. rex footprints, found in New Mexico and Montana, which did not reveal locomotion patterns.

The 23-foot-long trackway, consisting of three-toed prints about three feet in length, suggests the dinosaur moved at roughly 3.5 to 4.5 miles per hour despite an estimated weight of more than seven tons. Researchers linked the prints to T. rex based on size, shape, and the surrounding rock layer, which has yielded numerous tyrannosaur fossils, including a juvenile specimen nicknamed "Teen Rex" found nearby in 2022.

"Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior," said Dr. Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science.

The trackway was uncovered in 2025 on U.S. Forest Service land by Kent Hups, a high-school teacher and volunteer fossil hunter. He noted that his curiosity and observation led to the find.

"As a teacher, I'm always telling my students that science starts with curiosity, passion and careful observation," Hups said.

The site was digitally scanned in three dimensions by museum researchers, and lead author Peter Falkingham of Liverpool John Moores University analyzed the data remotely. Three of the four footprints are scheduled to be airlifted to the Denver Museum of Nature & Science later this year. The tracks date to approximately 66.5 million years ago, near the end of the Cretaceous period, representing one of the last known movements of the species before the mass extinction event.