Giant T. rex footprints in North Dakota reveal walking speed

Scientists from the Denver Museum of Nature & Science and Liverpool John Moores University have identified four three-toed footprints belonging to an adult Tyrannosaurus rex in the Hell Creek Formation near Marmath, North Dakota. The trackway, measuring about 23 feet (7 meters) in length, includes two left and two right prints, each roughly 3 feet (0.91 meters) long with a stride of about 13 feet (3.96 meters). High-resolution 3D scanning was used to capture detailed images of the prints, which date to approximately 66.5 million years ago. Researchers estimate the dinosaur was moving at 3.5 to 4.5 miles per hour, a speed comparable to a brisk human walk. The team plans to excavate three of the footprints later this year and transport them to the Denver Museum of Nature & Science.

"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. "As a teacher, I’m always telling my students that science starts with curiosity, passion and careful observation," added Kent M. Hups, a Northglenn High School teacher and co-author of the study.