A high school science teacher from Colorado has made a significant paleontological discovery while volunteering on a fossil excavation in North Dakota. Kent Hups, recovering from knee replacement surgery, found a trail of massive dinosaur footprints in the Hell Creek Formation near Marmarth, North Dakota, in July 2025. The trackway consists of four large three-toed prints, each about three feet long and two feet wide, with a stride length of approximately 13 feet. This marks the first confirmed walking trackway of a fully grown Tyrannosaurus rex ever documented.

Hups initially recognized the prints while carefully navigating the terrain, measuring the impressions with a tape measure and noting their distinct shape. He immediately contacted the excavation team leader with a photograph, suggesting they might have discovered T. rex footprints. The team leader, Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature and Science, approached the claim with initial skepticism, citing the natural variability of rock formations that can resemble footprints.

Following further examination, Lyson and his colleagues confirmed the identification based on the prints’ large size, narrow toe impressions, and the area's known abundance of T. rex fossils. The footprints are estimated to be about 66.5 million years old, dating back to the late Cretaceous period near an ancient riverbank. The discovery was made on federally managed land overseen by the U.S. Forest Service.

Prior to this find, only two isolated adult T. rex footprints had ever been documented, one in Montana and another in New Mexico. This new trackway, spanning 23 feet, provides unprecedented insight into the locomotion and stride of one of the largest terrestrial predators in history, which could weigh up to 10 tons.

Thomas Carr, a paleontologist at Carthage College in Wisconsin not involved in the excavation, emphasized the rarity and importance of the find, noting that despite more than 120 years of fossil searches in the Hell Creek Formation, confirmed T. rex trackways have remained elusive. He expressed hope that future research will uncover more remains of these prehistoric trailways.

The findings were published recently in the Journal of Vertebrate Paleontology, shedding new light on the movement and behavior of Tyrannosaurus rex during its final days.