These Four Giant Dinosaur Footprints Discovered in North Dakota Might Represent the First Trackway Made by an Adult T. Rex Ever Found

Roughly 66.5 million years ago, a hulking Tyrannosaurus rex marched through the then-swampy forested landscape of southwestern North Dakota. Now, paleontologists say they have unearthed four of the massive creature’s three-toed footprints—the first adult T. rex trackway ever found. Researchers describe their find in a study published September 8 in the Journal of Vertebrate Paleontology.

Kent Hups, a high school teacher and amateur fossil hunter based in Northglenn, Colorado, was the one who initially spotted the tracks in 2025. Hups was volunteering on a dig led by his friend Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science, just outside of Marmarth, North Dakota, when he spotted something unusual sticking out of the ground. When Hups got closer, he realized the lumpy, wedge-shaped protrusion looked a lot like three splayed toes, reports National Geographic’s Dustin Renwick.

Hups was convinced he’d discovered a T. rex footprint. But when he let Lyson know what he’d found, the paleontologist was more skeptical. Only two adult T. rex tracks had ever been uncovered—one in New Mexico and the other in Montana.

Still, the team returned to the site the next day, where they were shocked to discover several additional footprints—a trackway measuring roughly 23 feet long featuring two left and two right footprints, each around three feet long. Based on the stride lengths and foot lengths, researchers estimate the T. rex was walking at a speed of roughly 3.4 to 4.5 miles per hour. One footprint even appears to have an impression of a T. rex claw.

I never imagined that could lead me to a discovery like this,” Hups says in a statement. The researchers are convinced the footprints were made by a T. rex because of their size, shape and location. Numerous T. rex bones have been found in the same area, encased in 66- to 68-million-year-old geologic layers collectively known as the Hell Creek Formation, which spans eastern Montana, the Dakotas and Wyoming.

Finds include Sue, one of the largest and most complete T. rex skeletons ever discovered, and “Teen Rex,” the juvenile dinosaur discovered by three children in 2022. Gus, the T. rex fossil that sold for a record $50.1 million earlier this year, and Stan, which sold for $31.8 million in 2020 and is now on display at the Natural History Museum Abu Dhabi in the United Arab Emirates, were also found nearby. Though dinosaur bones are relatively common, it’s unusual to find large theropod footprints in the Hell Creek Formation, let alone trackways.