Paleontologists have identified the first known trackway belonging to an adult Tyrannosaurus rex, a discovery that offers rare direct evidence of how the iconic dinosaur moved across the landscape. The 23-foot-long series of footprints was found in southwestern North Dakota, within the fossil-rich Hell Creek Formation, and dates to approximately 66.5 million years ago.
The trackway consists of four three-toed footprints — two left and two right — preserved in ancient sediment. Researchers from the Denver Museum of Nature and Science in Colorado and Liverpool John Moores University in the United Kingdom first identified the prints last year. Their analysis confirms that the tracks were made by a full-grown T. rex, making this the first known trackway from an adult of the species.
Before this discovery, fossilized footprints attributed to adult T. rex were unknown, leaving a gap in the understanding of the animal's locomotion and behavior. While skeletal remains of T. rex are relatively well documented, footprints provide a different kind of evidence: a direct record of a living animal's stride, gait, and interaction with its environment. The North Dakota trackway preserves a short sequence of steps, allowing scientists to estimate the size and weight of the individual that made them.
The Hell Creek Formation, which spans parts of Montana, North Dakota, South Dakota, and Wyoming, is one of the most important sources of Late Cretaceous fossils in the world. It has yielded remains of T. rex, Triceratops, Edmontosaurus, and other dinosaurs that lived just before the mass extinction event that ended the Cretaceous period. The formation's sediments were deposited in river floodplains, a setting that occasionally preserved footprints when animals walked across wet mud or sand that later hardened into rock.
The discovery adds to a growing body of research on dinosaur trace fossils, which include tracks, burrows, and other evidence of behavior rather than body parts. Trackways can reveal details that skeletons cannot, such as speed, posture, and social behavior. In this case, the four prints suggest a steady walking pace rather than running, though the short length of the trackway limits how much can be inferred about the animal's speed.
The research team's finding was announced after careful study of the site and the prints. The tracks are now part of the scientific record and will likely be compared with other T. rex footprints and trackways from across North America. Such comparisons could help paleontologists better understand variation in gait and size among individuals of the species.
The discovery also highlights the ongoing importance of the Hell Creek Formation for paleontology. Despite more than a century of excavation, the region continues to produce significant finds, from new dinosaur specimens to trace fossils that capture moments of ancient life. The adult T. rex trackway is a reminder that even well-known dinosaurs can still surprise scientists with direct evidence of their existence.
For now, the trackway stands as the first confirmed set of footprints from an adult T. rex, a milestone in dinosaur paleontology. Further study of the site and the surrounding sediments may reveal additional tracks or context about the environment in which the animal lived. The discovery was made by researchers from the Denver Museum of Nature and Science and Liverpool John Moores University, whose work adds a new chapter to the study of the most famous dinosaur of all.