Not only did the Tyrannosaurus rex have tiny arms in relation to its giant body, but according to a new study, it apparently couldn’t move faster than 12 miles per hour.

The consequences of moving faster than this speed were great; its legs would have broken under its own weight.

New research from the University of Manchester says the sheer size and weight of  the T. rex means it couldn’t move at high speed, as its leg-bones would have buckled under its own weight load. (Credit: University of Manchester)
New research from the University of Manchester says the sheer size and weight of the T. rex means it couldn’t move at high speed, as its leg-bones would have buckled under its own weight load. (Credit: University of Manchester)

Published in the journal PeerJ, the research team—led by Professor William Sellers—used a computer simulation to assess the muscles and skeletal strength of this massive animal to determine its gait.

This study sheds new light on the hunting capabilities and lifestyle of the iconic dinosaur; changing what scientists, and the general public, thought they knew about the T. rex. “That means that T. rex was actually quite slow and therefore not a pursuit predator,” Professor Sellers told BBC News. “Running would have been impossible because its skeleton just isn’t strong enough.”

While T. rex could not engage in high-speed pursuits when chasing its prey, it could still easily take down a human. The T. rex became less agile with age, with additional body mass and size slowing down its maximum speed. It then had to adapt and change the way it hunted. Previously, it was widely assumed that the T. rex could reach maximum speeds up to 45 mph.

A Tyrannosaurs Rex robotic dinosaur from the live show 'Walking With Dinosaurs', based upon the hit BBC TV series of the same name. (Credit: by Oli Scarff/Getty Images)
A Tyrannosaurs Rex robotic dinosaur from the live show ‘Walking With Dinosaurs’, based upon the hit BBC TV series of the same name. (Credit: by Oli Scarff/Getty Images)

The study not only reveals new information on the T. rex, but other creatures as well. It suggests that other large two-legged dinosaurs—Giganotosaurus, Mapusaurus and Acrocanthosaurus—were also unable to run at high speeds.

Whether it changes Hollywood’s depiction of T. rex’s high-speed chases or not, the T. rex probably had a more sedentary lifestyle than previously thought.