First Adult T. rex Trackway Reveals a 66.5-Million-Year-Old Walk

A newly described footprint trail in southwestern North Dakota offers an unusually direct view of an adult tyrannosaur in motion. The fossilized sequence, dated to about 66.5 million years ago, is reported as the first trackway attributed to an adult Tyrannosaurus rex—a distinction that matters because a connected series of steps can reveal gait and direction in ways a skeleton or lone footprint cannot. 34

What was discovered near Marmarth

The trackway was found in 2025 on U.S. Forest Service-administered land near Marmarth, in North Dakota’s Hell Creek Formation. Kent M. Hups, a high-school teacher and co-author of the study, discovered the site.

Researchers documented a trail approximately 7 meters, or 23 feet, long. It contains four large, three-toed footprints, each roughly 1 meter (3 feet) in length. The scientific paper places the track-bearing layer about 33 meters below the Hell Creek–Fort Union formation contact and estimates its age at approximately 66.5 million years. 34

The find is not the first isolated print that has been proposed as T. rex. Its importance is that it is a continuous sequence attributed to an adult animal, rather than a single possible footfall. 3

Why scientists think the trackmaker was an adult T. rex

Footprints rarely preserve a species name as neatly as a labeled bone. The study therefore treats the identification as an evidence-based attribution rather than absolute proof.

The tracks are exceptionally large and tridactyl, meaning they show three main toes. Their dimensions and morphology are consistent with a large tyrannosaur, while the Hell Creek Formation is well known for T. rex body fossils. The researchers conclude that an adult T. rex is the most plausible maker of the trail. 3

That careful language is important. The study notes that previously known tyrannosaurid tracks and trackways had not enabled a clear comparison with an adult T. rex. This new trail provides a much stronger basis for linking a giant Hell Creek trackmaker with the famous predator. 3

A rare record of a dinosaur walking

A skeleton can reveal the structure of an animal’s legs and feet, but it does not preserve one particular journey. A single footprint records one contact with the ground. Four consecutive impressions add a sequence: researchers can compare the alternating feet, spacing, direction of travel, and stride.

In this case, the reported stride is about 13 feet. The researchers interpret the spacing as a walking gait, not a sprint. That makes the trackway a snapshot of ordinary locomotion by a very large theropod, rather than evidence of a chase or attack. 4

The trail is still a small sample. Four prints cannot establish how T. rex generally hunted, lived socially, or behaved throughout the day. What it does provide is rare, direct evidence that one adult-sized tyrannosaur crossed this surface at a measured pace roughly 66.5 million years ago. 34

How the team preserved the evidence digitally

Scientists from the Denver Museum of Nature & Science and Liverpool John Moores University studied the trackway, with the results published in the Journal of Vertebrate Paleontology. 4

High-resolution 3D documentation is central to the work because the exposed tracks are vulnerable to weathering. Digital surface models allow researchers to measure and inspect the prints without relying solely on the original outcrop. They also preserve a detailed record that can be revisited, compared, and reproduced after excavation. 4

Liverpool John Moores University palaeobiologist Peter Falkingham, a specialist in fossil tracks, was among the researchers interpreting the evidence. The museum’s Tyler Lyson led fieldwork, and the team used detailed scanning to capture both individual impressions and the full trail. 4

What happens to the footprints next

The Denver Museum of Nature & Science plans to recover three of the four footprints and transport them by helicopter to Denver. The museum has said it will share recovery updates, but the available announcement does not specify a final exhibition date or gallery plan. 4

For visitors and researchers alike, the value of recovery is not only spectacle. Alongside the scans, preserved footprints can support future study of their shape, sedimentary context, and the movement of one of prehistory’s most recognizable animals. 34