A set of tyrannosaur footprints is giving researchers new insight into the speed of the prehistoric beasts. As it turns out, humans may have been able to outrun them. In fact, the new estimate proposes that the famous T. Rex could travel up to 5 miles per hour—slower than the average power walker.

“If you were out walking a juvenile T. Rex, you’d be comfortable at a brisk walk. If you were walking an adult, you’d be jogging,” says Eric Snively, a vertebrate paleontologist at the University of Wisconsin.

According to Scott Persons, a vertebrate paleontologist at the University of Alberta and lead author of the new study, T. Rex tracks are very rare, even in areas where their skeletal fossils are abundant. Fossilized tracks give us important insight into the size of dinosaurs, as well as their gaits and walking speeds.

Containing a total of three footprints, the new trackway was found in 66-million-year-old rocks that formed along an ancient shoreline in Wyoming. The first footprint is well preserved. Researchers believe it is either from an adolescent T. Rex, or a smaller theropod called Nanotyrannus lancensis. But whatever species made the track, it’s clear that the creature had a “brisk walking speed.”

To figure out the dinosaur’s speed, researchers first estimated how high the dinosaur’s hips must have been above the ground, based on the footprint length. Using mathematical formulas, they determined the creature hips were between 1.56 and 2.07 meters off the ground. They then measured the distance between the footprints and used an equation to estimate the dinosaur’s walking speed, yielding a result of between 2.8 and 5 miles per hour.

Of course, the analysis does not prove that T.Rex was incapable of going faster. Trackways are records of single events, so the odds are the footprints don’t capture a dinosaur’s “peak performance.”

“There are as yet no known trackways of running tyrannosaurs, so we don’t know for sure just what their upper-speed limit was,” Thomas Holtz Hr., a vertebrate paleontologist, told Science Magazine.

Still, the idea that we’d be able to comfortably stroll next to a dinosaur is pretty mind-boggling.

Source: Science Magazine, io9