Kent Hups was volunteering with the Denver Museum of Nature & Science when he spotted a T. rex footprint and then soon found three more, forming a trackway. The museum said on September 9, 2026, that the trackway extends for 23 feet (7 meters). The four large footprints are each roughly 3 feet (1 meter) long, with two from the left foot and two from the right. It is the first known discovery of an adult T. rex trackway.
The researchers published their peer-reviewed study in the Journal of Vertebrate Paleontology on September 8, 2026. They estimated that the T. rex was walking at a speed of about 3.5 to 4.5 miles per hour (5.6 to 7.2 kilometers per hour), roughly the pace of a brisk human walk. The footprints are preserved in sandstone at the Hell Creek Formation and are about 66.5 million years old. Hell Creek is a famous fossil-rich site that preserves rocks and fossils from the final part of the Cretaceous.
The footprints are raised rather than sunken because of how they were preserved. The dinosaur stepped into soft mud and made an indent in the ground. Later, the footprint pooled with water and then sand or mud washed into the depression, filling it. Eventually that sediment hardened, and over millions of years the filled-in footprint became rock. Softer rock around the surrounding footprints then eroded away, leaving behind the harder sediment that had filled in the footprints. What remains today is essentially an inverted footprint: a natural cast of the original track. Ancient footprints are also preserved in other ways. Sometimes the ground the dinosaur stepped on remains harder than subsequent layers, leaving a preserved indentation, such as in Ouray, Colorado.
Several clues point to the trackway belonging to a T. rex. The footprints themselves are huge, and the narrow shape of the toes suggests they are from a T. rex. The area around the trackway is also rich in T. rex fossils. Scientists have found individual footprints in this area before that they attributed to adult T. rexes, but this is the first sequence of footprints — a trackway — that they believe is from a T. rex.
Co-author Tyler Lyson of the Denver Museum of Nature & Science said: "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. rexes."
The researchers used high-resolution 3D surface scanning to document the footprints and the entire trackway. Eventually, they plan to excavate the tracks themselves to display in the Denver Museum of Nature & Science. The scans produced such a detailed digital model of the tracks that the lead author never even saw them in person. Peter Falkingham, a professor of paleobiology at Liverpool John Moores University and a dinosaur track expert, said: "The technology we're able to apply in the digital age means my colleagues could scan the tracks in the field and then send the 3D information over to me to visualize on my computer and in VR, enabling me to take as close a look as they did in person."
Hups, who became a co-author of the paper, said: "As a teacher, I'm always telling my students that science starts with curiosity, passion and careful observation. I never imagined that could lead to a discovery like this."
The study is titled "A large tridactyl trackway from the Upper Cretaceous Hell Creek Formation of North Dakota, likely attributable to an adult Tyrannosaurus rex." The tracks will soon be on display at the Denver Museum of Nature & Science.