First Adult Tyrannosaurus rex Trackway Discovered in North Dakota

Scientists have verified the discovery of the first adult Tyrannosaurus rex trackway, a series of four three-toed footprints preserved in the Hell Creek Formation of North Dakota. The 23-foot-long trackway, estimated to be about 66.5 million years old, was located by Kent Hups, a high-school science teacher and amateur fossil hunter, on land managed by the U.S. Forest Service near Marmarth.

Researchers identified the maker as T. rex based on the size and narrow toe shape of the prints, as well as the abundance of T. rex fossils in the surrounding strata. The trackway shows two left and two right footprints with an average stride of roughly 13 feet, suggesting the animal was moving at an estimated 3.5 to 4.5 miles per hour.

"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," said Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science, who led the excavation.

The team employed high-resolution 3D surface scanning to create digital models of the prints, enabling detailed analysis and virtual reality visualization. Lead author Peter Falkingham, a paleobiology professor at Liverpool John Moores University, noted that the technology allowed colleagues to scan the tracks in the field and share the data for remote examination.

"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," Hups said.

Three of the footprints are slated for recovery by helicopter later this year and will be transported to the Denver Museum of Nature & Science, where they will be displayed and further studied.