Films such as Jurassic Park have led us to believe that Tyrannosaurus rex was capable of chasing down its prey at full tilt. New research done with simulations suggest this dino was no sprinter, and that it couldn't move any faster than a brisk walk. Well, a brisk walk for a nine tonne carnivore. At a top speed of 19km/h, you'd still be hard pressed to outrun this prehistoric beast.