Adult Tyrannosaurus rex footprints uncovered in North Dakota
Paleontologists have identified a 7-meter trackway of four large footprints attributed to an adult T. rex, dating to about 66.5 million years ago.
Researchers have described a 7-meter long trackway in North Dakota that preserves four footprints about one meter long, which they attribute to an adult Tyrannosaurus rex. The footprints, cemented by calcium carbonate, show an average stride of roughly four meters and suggest a walking speed of 1.5 to 2 meters per second.
The find, reported in the Journal of Vertebrate Paleontology, represents the first known adult T. rex trackway and is dated to approximately 66.5 million years ago, shortly before the asteroid impact that ended the age of non-avian dinosaurs. The researchers note that finding both skeletal and trace fossils together is rare because the preservation conditions differ and tracks can be easily eroded.
"Bones tell us an enormous amount about these animals, but footprints capture a moment of behavior," said Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science and a co-author of the study.
"With a trackway, we can actually follow an animal as it moved across the landscape. That is incredibly rare for T. rex," Lyson added.
The trackway was discovered in 2025 by Kent Hups, a science teacher and amateur fossil enthusiast, who said the discovery underscores the role of curiosity and observation in scientific work. Three of the footprints are slated for transport to the Denver Museum of Nature & Science for preservation and study.
The researchers compare the estimated walking speed to that of a human, noting it is comparable to a normal walking pace. They also reference earlier findings of smaller tyrannosaurid tracks that suggested possible group behavior among related species.