A sequence of four large fossil footprints in North Dakota has been identified as the first known trackway made by an adult Tyrannosaurus rex, preserving a rare snapshot of the animal in motion about 66.5 million years ago.
The roughly seven-meter trackway was found in the Hell Creek Formation and contains alternating three-toed prints attributed to a large adult T. rex. Researchers used high-resolution 3D scanning to document the impressions and estimate how the animal moved.
Unlike bones, trackways record behavior at a particular moment. The spacing and orientation of the prints can reveal walking speed, stride and posture, adding information that skeletons alone cannot provide.
The discovery also shows how unusual conditions can preserve footprints that would normally disappear. Researchers plan to preserve and study the specimens further, with some expected to be moved for museum display.
Source: Reporting on research published in the Journal of Vertebrate Paleontology, Sept. 2026.
