The approximately 66.5-million-year-old trackway was found in the Hell Creek Formation in southwestern North Dakota. It consists of four enormous three-toed footprints that preserve a short sequence of steps made by what researchers believe was an adult T. rex.
Unlike isolated dinosaur footprints, a trackway allows scientists to study an animal’s movement. In this case, the preserved sequence provides evidence that the enormous predator was walking rather than running, giving researchers a rare behavioral snapshot from the final part of the Cretaceous Period.
A rare trail from an adult T. rex
The trackway stretches for approximately 23 feet (7 meters) and contains two left and two right footprints. Each print measures about 3 feet (0.9 meters) long, making them consistent with the enormous feet expected from an adult T. rex.
Researchers identified the dinosaur as the most likely trackmaker because of the footprints’ exceptional size and their narrow toe shape. The surrounding area also contains an abundance of T. rex fossils, providing additional evidence supporting the identification.
Scientists had previously identified isolated footprints that were attributed to adult T. rex. However, this discovery is different because the four prints form a continuous sequence that can be followed across the ancient landscape.
That distinction is important because bones primarily reveal anatomy, while footprints can preserve evidence of behavior.
The T. rex was walking at a brisk pace
The arrangement of the footprints allowed researchers to estimate how quickly the animal was moving when it left the trail.
