Contrary to popular belief, the tyrant lizard king was not built for speed. Instead, the mighty Tyrannosaurus rex was typically restricted to a brisk walk, according to a rigorous new computer model.
The top speed of a T. rex has been a long-standing debate among paleontologists. Previously, the best estimates indicated that the large lizard could run between 11 and 33 miles an hour.
That means that in an imagined race between a person and the iconic dinosaur, there was the possibility that a T. rex could outrun the world’s fastest human, who clocks in around 27 miles an hour.
Now, paleontologist William Sellers from the University of Manchester and his colleagues have crunched the numbers using even more comprehensive information.
According to their results, published this week in the journal PeerJ, the lower end of the estimate is more accurate: T. rex probably could only reach around 12 miles an hour. Any faster, and its bones would have shattered.
Decades ago, paleontologists would point to individual parts of the T. rex skeleton and say it proved that the dinosaur was either fast or slow. Superficially comparing T. rex limbs to ostrich limbs, for instance, it stood to reason that the 40-foot-long dinosaur could have been quick. (Here’s what it would feel like to pet a T. rex.)
With the advent of more complex biomechanical models, though, scientists can get much closer to an answer. (Also see our best look yet at a tyrannosaur’s face.)