Colorado science teacher Kent Hups found the first known T. rex trackway in North Dakota’s Hell Creek Formation. Researchers identified at least five prints; four suggest a 13-foot stride and walking speed of 3.5–4.5 mph, according to study coauthor Tyler Lyson.
Hups first spotted two prints in July 2025. Excavation uncovered two more, and researchers found a fifth this summer. The three-toed prints’ size and shape helped distinguish them from tracks of the duck-billed dinosaur Edmontosaurus. Before the discovery, scientists had reported only two isolated footprints attributed to T. rex. The study was published Sept. 8 in the Journal of Vertebrate Paleontology.
The speed estimate is not a measure of the dinosaur’s maximum: paleontologist Thomas Holtz said the tracks likely formed in wet soil, while animals move fastest on firm ground. The Denver Museum of Nature & Science plans to collect three prints for analysis of tissue and skin impressions.
