Are You Faster than a T. Rex?

By Kerry Connell

Generations of kids have been fascinated by the gigantic size, fierce nature and presumed speed of the Tyrannosaurus Rex. But was this “king of the tyrant lizards” as quick as we imagine?

Simulated Dinosaur Speed

The speed of dinosaurs has been widely debated since the 19^th century. In 2007, paleontologists William Sellers and Phillip Manning at the University of Manchester published results from GaitSym, their customized computer simulation that used fossils to recreate dinosaur anatomies. Using these models, Sellers and Manning approximated the top speeds of five different carnivorous, bipedal dinosaurs — Compsognathus, Velociraptor,Dilophosaurus, Allosaurus and T. Rex — and found T. Rex to be the slowest of the pack, but still faster than the average human.

Clues to Prehistoric Speed

A newer study to be published in the June 2016 issue of Cretaceous Research helps to refine the hypothesized speed of T. Rex locomotion. Using sets of fossilized footprints found in rocks at an ancient shoreline in Wyoming, scientists were able to identify the dinosaur that made the tracks and estimate its size, gait and speed.

From the 18.5” wide imprints, with three longer forward-facing toes and one shorter, thumb-like digit facing backwards, a team of paleontologists led by Scott Persons of the University of Alberta in Edmonton, Canada, determined that the footprints were made by a juvenile theropod. Based on the distance between the prints and the estimated height of the dinosaur’s hips, the scientists had been able to calculate a walking speed of two to five miles per hour, or about a 12- to 21-minute mile.

This estimated speed was consistent with though slower than the 6.8 miles per hour finding from another study — just under a nine-minute mile pace that many average runners could exceed. According to Eric Snively at the University of Wisconsin, “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.”