Paleontologists have confirmed the discovery of the first known adult Tyrannosaurus rex trackway, providing researchers with a continuous trail of footprints to study how the giant predator moved. The rare set of four connected footprints was uncovered in the badlands of southwestern North Dakota near Marmarth, close to the Montana border, on federal land administered by the U.S. Forest Service.
Discovery of the First Adult T. Rex Trackway
The site is located within the Hell Creek Formation, a geological area spanning eastern Montana, Wyoming, and the Dakotas that dates back roughly 66.5 million years to the latest Cretaceous period. Until this find, only two confirmed isolated adult T. rex footprints had ever been discovered anywhere in the world—one in New Mexico and one in Montana—neither of which provided a sequence to study animal movement.
The discovery was initially made in 2025 by Kent Hups, a high school science teacher at Northglenn High School and amateur fossil hunter from Northglenn, Colorado, while he was volunteering on a dig led by Denver Museum of Nature & Science senior curator of vertebrate paleontology Tyler Lyson. Hups spotted a lumpy, wedge-shaped protrusion resembling three splayed toes sticking out of the ground.
Walking Pace and Behavioral Insights
The complete trackway measures roughly 23 feet long and consists of four three-toed impressions, comprising two left and two right footprints. Each individual print is approximately 3 feet long. Based on the spacing between each impression, researchers determined that the dinosaur had a stride of about 13 feet.
By analyzing the stride length and foot dimensions, the research team estimated that the T. rex was moving at a speed of roughly 3.4 to 4.5 miles per hour. This pace corresponds to a brisk human walking speed, suggesting that the animal was walking rather than sprinting when it crossed the landscape.
Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior. With a trackway, we can actually follow an animal as it moved across the landscape. That is incredibly rare for T. rex,
Tyler Lyson said in a statement.
High-Tech 3D Documentation and Preservation
To examine and document the fragile site without causing damage, the excavation team utilized high-resolution 3D surface scanning technology in the field. Peter Falkingham, a professor of paleobiology at Liverpool John Moores University and lead author of the study, used the digital data to visualize the tracks remotely on his computer and in virtual reality.
The footprints are preserved through post-depositional cementation, a process where groundwater rich in calcium carbonate minerals flowed through porous sandstone and cemented the original depressions left in muddy overbank sediment into much harder stone. Over millions of years, erosion stripped away the softer surrounding rock, leaving the durable footprint casts exposed.
The findings were detailed in a study published in the Journal of Vertebrate Paleontology.
Future Plans for the Fossil Site
Due to the risk of weathering and erosion, plans are underway to recover the footprints. Officials expect to lift three of the footprints by helicopter for transport to the Denver Museum of Nature & Science, where the institution plans to share updates with visitors.
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Reflecting on the unexpected discovery, Hups noted the rarity of finding such a trackway. As a teacher, I’m always telling my students that science starts with curiosity, passion, and careful observation. I never imagined that could lead me to a discovery like this,
he said.
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