The Discovery
In July 2025, high school geology teacher Kent Hups was volunteering on a fossil dig in the badlands of southwestern North Dakota when he noticed an unusual bulge in the rock. Located on federal land near Marmarth within the Hell Creek Formation, the site revealed a line of four 66.5-million-year-old footprints. Researchers concluded that these tracks were left by a fully grown adult Tyrannosaurus rex.
What Scientists Found
The sequence features four consecutive prints—two from the left foot and two from the right—spanning roughly 23 feet (7 meters) across ancient ground. Each three-toed print is about 3 feet (1 meter) long and 2 to 2.5 feet (0.6 to 0.8 meters) wide, separated by a stride length of about 13 feet (4 meters). From this spacing, scientists calculated that the animal was walking at approximately 3.5 to 4.5 miles per hour (5.6 to 7.2 kilometers per hour), similar to the pace of a brisk human walk.
The long shape of the prints relative to their width indicated a meat-eating dinosaur. In the Hell Creek ecosystem, only T. rex and the plant-eating Edmontosaurus were large enough to leave prints of this magnitude, and their foot structures are distinctly different.
Why It Matters
While fossilized bones reveal how an animal grew and looked, trackways capture specific moments of living behavior. Before this find, scientists had documented only two isolated adult T. rex footprints globally—one from New Mexico and another from Montana. This newly analyzed trackway provides the first record of an adult T. rex taking continuous steps across the landscape.
A research team led by Peter Falkingham used high-resolution 3D surface scanning to document the trackway digitally. Plans are underway to transport three of the footprints by helicopter to the Denver Museum of Nature & Science, where scientists hope to examine the specimens for fine details such as fossilized skin impressions.
Source: dinosaur fossil discovery - BingNews · Published October 11, 2026 · Photo by James St. John via Openverse