Marmarth, North Dakota – A newly documented set of footprints has given researchers a rare window into how one of the largest carnivorous dinosaurs moved across its ancient landscape. The 23-foot trail, preserved in 66.5-million-year-old mudstone, was uncovered on a slope within the Hell Creek Formation. Its discovery has allowed scientists to calculate a walking speed that directly addresses a question long posed by the public and paleontologists alike.
A Volunteer’s Unexpected Find
Kent Hups, a Colorado high school science teacher and volunteer research associate at the Denver Museum of Nature & Science, spotted the first prints during a July 2025 research expedition. The three-toed impressions, characteristic of an adult Tyrannosaurus rex, stood out against the surrounding rock. Hups described his initial response as total disbelief, sitting with the tracks for some time before accepting what he was seeing. ([1])
The four footprints form the first known adult T. rex trackway, a sequence that had never been recorded before. Previous finds had yielded only isolated prints. This continuous path now supplies direct behavioral evidence rather than relying solely on skeletal reconstructions.
Calculating a Dinosaur’s Pace
By measuring the 13-foot spacing between prints and estimating the animal’s leg length, researchers determined that the tyrannosaur moved at roughly 1.6 miles per hour. That pace falls well below the average walking speed of a healthy adult human. The calculation draws on established methods that relate stride length to speed in living animals and applies them to the fossil record.
Paleontologist Scott Persons noted that a trail of tracks makes such estimates possible in a way isolated bones cannot. The data point to a deliberate, energy-efficient gait rather than a hurried movement. The findings appear in a September 2026 paper in the Journal of Vertebrate Paleontology.
Why Trackways Matter
Dr. Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science, emphasized that footprints capture a moment of behavior. Bones reveal anatomy and possible capabilities, yet a trackway shows how the animal actually progressed across the terrain. Such records remain exceptionally rare for T. rex.
The Marmarth discovery adds a measurable dimension to long-standing debates about dinosaur locomotion. It also underscores the value of sustained fieldwork by trained volunteers who bring both patience and scientific curiosity to remote sites. Continued study of the Hell Creek Formation may yield additional trackways that further refine these insights.
The trail stands as a quiet reminder that even the most formidable creatures of the past left behind evidence of ordinary movement. For those drawn to the region’s fossil-rich landscapes, the find highlights the ongoing rewards of careful observation in places where deep time remains visible on the surface.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.