First Known Adult T. rex Trackway Found in North Dakota

The trackway is the first of its kind to be found and identified. Isolated footprints and tracks from juvenile T. rex or related species have been discovered before, but this is the first known series of footprints left by a wandering T. rex, The Guardian reported.

Each footprint is about 3 feet long, with a stride of about 13 feet. The research team used high-resolution 3D surface scanning to document each footprint and create physical 3D reproductions. From that work, researchers made a rough estimate that the animal was walking about 3.5 to 4.5 mph, roughly the same as a brisk human walking pace.

Tyler Lyson, senior curator of vertebrate paleontology at the Denver Museum of Nature and Science, said bones reveal a great deal about such animals, but footprints capture a moment of behavior. “With a trackway, we can actually follow an animal as it moved across the landscape,” Lyson said. “That is incredibly rare for T rex.”

T. rex lived about 66 to 68 million years ago during the Cretaceous Period, according to the known fossil record. The dinosaurs stood 12 to 13 feet tall and were among the last non-avian dinosaurs to walk the Earth before a mass extinction event wiped them out.

Three of the discovered footprints are set to be recovered by helicopter later this year and transported to the museum in Denver. The site was stumbled upon by Kent Hups, a Colorado schoolteacher, long-time museum volunteer and co-author of the paper. “As a teacher, I’m always telling my students that science starts with curiosity, passion and careful observation,” Hups said. “I never imagined that could lead me to a discovery like this.”