Paleontologists have identified what they say is the first known trail of footprints left by an adult Tyrannosaurus rex: a sequence of four connected tracks preserved in the rugged badlands of southwestern North Dakota, near the Montana border.
The discovery is detailed in a new paper published this week in the Journal of Vertebrate Paleontology. Until now, scientists had confirmed only two single adult T. rex footprints worldwide — one in New Mexico and another in Montana — and neither offered clues about the dinosaur’s stride or movement.
“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. “With a trackway, we can actually follow an animal as it moved across the landscape. That is incredibly rare for T. rex.”
National Science Foundation
The rare trackway was uncovered in 2025 on U.S. Forest Service land near Marmarth, North Dakota. It was found by Kent Hups, a high school teacher and amateur fossil hunter who was volunteering on one of Lyson’s field expeditions.
“As a teacher, I’m always telling my students that science starts with curiosity, passion and careful observation,” Hups said. “I never imagined that could lead me to a discovery like this.”
Stretching roughly 23 feet, the trackway includes four three-toed prints, each measuring about 3 feet in length. By studying the distance between the footprints, researchers estimated that the massive predator was moving at a walking pace of about 3.5 to 4.5 mph, even though it weighed more than seven tons.
National Science Foundation
Scientists linked the tracks to T. rex because of their size, form and geological context. The surrounding rock layers have yielded an unusually rich collection of tyrannosaur remains, including a juvenile fossil nicknamed “Teen Rex,” discovered in the same badlands by three boys on a family hike in 2022.
Researchers from the Denver Museum scanned the site in 3D, allowing lead author Peter Falkingham of Liverpool John Moores University in England to study the trackway remotely. Falkingham analyzed the digital data and wrote the paper without traveling to North Dakota himself.
Three of the four footprints are set to be airlifted out by helicopter this fall and taken to the Denver Museum of Nature & Science.
The tracks date to about 66.5 million years ago, near the very end of the Cretaceous period, one of the last walks any T. rex is known to have taken before scientists believe an asteroid impact wiped out the dinosaurs.
