Scientists have uncovered the first known continuous trackway left behind by an adult Tyrannosaurus rex, providing a rare 66.5-million-year-old behavioral snapshot of the apex predator just before the end-Cretaceous extinction. According to research published in the Journal of Vertebrate Paleontology, the 23-foot trail preserves four large footprints discovered in the badlands of North Dakota.
Discovery of the North Dakota Trackway
Northglenn High School science teacher and amateur fossil collector Kent Hups discovered the tracksite in 2025, according to findings detailed in the study. The continuous trail extends roughly 7 meters and features four distinct tridactyl impressions. Each footprint measures about 1 meter long and up to 0.80 meters wide. Weathering has impacted the site, but the impressions remain clearly cemented by calcium carbonate.
“Science starts with curiosity, passion and careful observation,” Hups said, reflecting on the discovery.
While researchers previously documented isolated T. rex footprints in states like Montana and New Mexico, this find marks the first time a continuous series of tracks from an adult of the species has been recorded.
Walking Speed and Behavioral Insights
The spacing between the footprints indicates an average stride of about 4 meters, or 13.1 feet. By analyzing this stride length, the research team calculated a walking speed of 1.5 to 2.0 meters per second, which translates to roughly 3.3 to 4.5 miles per hour. This pace matches expectations for a massive theropod moving deliberately across its environment.
“Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior,” said Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science and a co-author of the study.
The trackway dates to approximately 66.5 million years ago, placing it right on the eve of the Chicxulub asteroid impact that wiped out non-avian dinosaurs. Researchers utilized the surrounding stratigraphic and sedimentary context to determine this timeline.
Recovery Challenges and Conservation
Accessing the tracksite presents major hurdles. The footprints sit beneath a steep, unstable overburden of a local “gumbo” butte, rendering extended onsite excavation impossible. To protect the site from destruction, the research team plans to recover three of the footprints. Workers will airlift the specimens to the Denver Museum of Nature & Science for permanent conservation and future public display.
Study authors emphasize several scientific caveats regarding fossilized tracks. Footprints and skeletal remains rarely fossilize together because they require distinct preservation environments. Furthermore, shifting sediments and similar three-toed prints from other dinosaur groups can obscure identification, leading the team to caution that “footprints are not feet.” Nonetheless, the specific size, shape, geological age, and geographic location point firmly to an adult Tyrannosaurus rex as the trackmaker.
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