Paleontologists have uncovered the first known series of footprints made by an adult Tyrannosaurus rex, according to research published in the Journal of Vertebrate Paleontology. The unprecedented 23-foot-long trackway consists of four connected, three-toed footprints discovered in the badlands of southwestern North Dakota, not far from the Montana border.
First Known Adult T. rex Trackway Discovered in North Dakota
Before this discovery, only two isolated adult T. rex footprints had ever been confirmed globally—one in New Mexico and one in Montana—neither of which demonstrated how the animal moved. Researchers emphasize that while bones provide vast structural knowledge, footprints capture a transient moment of behavior, allowing scientists to follow a prehistoric animal as it traversed a landscape.
The discovery was made in 2025 by Kent Hups, a high school teacher, long-time museum volunteer, and amateur fossil hunter who was volunteering on a dig led by the Denver Museum of Nature & Science. The site is located on the Dakota Prairie Grasslands in Slope County, an area managed by the US Forest Service.
Behavior, Speed, and Physical Dimensions
The trackway comprises two left and two right footprints. Each individual print measures roughly 3 feet (or about 3.3 feet according to alternate measurements) in length. Based on the spacing between the impressions, researchers calculated that the dinosaur had a stride of about 13 feet.
By analyzing the data, the research team estimated that the adult T. rex was walking at a speed of approximately 3.5 to 4.5 miles per hour—comparable to a brisk human walking pace—despite weighing more than seven tons. The tracks date back approximately 66.5 million years to the very end of the Cretaceous period, marking one of the final walks taken by a T. rex before the mass extinction event caused by an asteroid impact wiped out the non-avian dinosaurs.
Scientists attributed the impressions to a T. rex based on their size and shape, as well as the surrounding geology of the Upper Cretaceous Hell Creek Formation. The local area has yielded an unusually high number of tyrannosaur bones, including a juvenile specimen known as “Teen Rex” found nearby in 2022 by three boys on a family hike.
Advanced 3D Technology and Future Recovery
The footprints are preserved as fine-grained sandstone concretions cemented with calcium carbonate, which nucleated around the original footprint depressions. To document the site thoroughly, researchers from the Denver Museum of Nature & Science performed high-resolution 3D surface scanning of each print and created physical reproductions.
This digital workflow allowed Peter Falkingham, a professor of paleobiology at Liverpool John Moores University in England and lead author of the study, to analyze the data and write the paper without needing to visit North Dakota in person. Falkingham utilized the 3D information on his computer and in virtual reality to examine the tracks in detail.
Plans are underway to recover three of the four discovered footprints. Officials intend to airlift the specimens out of the badlands by helicopter and transport them to the Denver Museum of Nature & Science.