Referring to a scene in the sci-fi film, he added: ''It might well have caught Jeff Goldblum in Jurassic Park, had he stayed outside the Jeep and in the slippery mud.'' Had it moved from a brisk walk to a sprint, the dinosaur's legs would have snapped under the weight of its body. New research published in PeerJ suggests the size and weight of a T. rex would have prevented it from running, and that it couldn’t move any faster than 5.4 meters per second, or 12 miles per hour. While the running ability of T-rex has been hotly debated among palaeontologists for decades, the consensus from previous biomechanical models was that the Cretaceous-era carnivore could manage speeds of up to 45 mph (75 kmh). “The muscles need to be able to generate sufficient power to allow high-speed locomotion, but at the same time the skeleton has to be able to cope with the loads generated by the high speed,” said Professor William Sellers from the university’s School of Earth and Environmental Sciences 
 
 “...This is where it fails. Advertisement 
 
 For the analysis, Sellers combined two established techniques used to study the biomechanical properties of animals, namely multibody dynamic analysis (MBDA) and skeletal stress analysis (SSA). ''That means that T. rex was actually quite slow and therefore not a pursuit predator.'' “It certainly would not have been able to chase down faster-moving prey animals,” said Sellers.
– Jurassic Park had us all fooled: Outstripping a Tyrannosaurus rex in a Jeep would've been easy-peasy because, well, T. rex couldn't run. After much debate about how fast T. rex moved—previous estimates suggested up to 45 miles per hour—scientists at the University of Manchester used advanced computer simulations to come up with the most accurate assessment yet. Taking into account the beast's muscles and skeleton, they discovered running would've been "impossible" without a T. rex's legs buckling under its 7-ton weight, per the BBC. Study author William Sellers says T. rex instead walked at a pace of up to 12 miles per hour—a fast jog for humans and less than half of Usain Bolt's top speed of 27.8mph, report Reuters and Buzzfeed. As a researcher not involved in the study tells National Geographic, there's "no way T. rex could have chased down that Jeep in Jurassic Park if it was going at highway speeds. Maybe if it was in first gear, but even that's a big if." While it's a welcome discovery for anyone who might find themselves transported back in time, it also provides insight into how T. rex hunted. Juveniles may have been faster moving, but an adult T. rex "certainly would not have been able to chase down faster-moving prey animals," Sellers says. That means T. rex might have hid in forested areas and launched ambush attacks, or it might have dined mostly on slow-moving dinosaurs like Triceratops, reports Gizmodo. (T. rex sure had a nasty bite.)