LONDON - Tyrannosaurus rex, the mighty predator that lived about 85 million years ago, was probably just a plodder and not the quick-footed killer depicted in Hollywood blockbusters, scientists said. Far from chasing its prey at speeds of up to 45 mph (70 kph), as some studies have suggested, the fearsome creatures may not have been able to run at all. „These animals were no speed demons,“ John Hutchinson, of Stanford University in California, said in an interview. The biologist who specialises in the evolution of movement said the science of how animals move shows that big creatures do not go fast. At about 12 metres long, up to 6 metres tall and weighing about 6,000 kilos, Tyrannosaurus rex was very big. Hutchinson and Mariano Garcia, of Borg-Warner Automotive in Ithaca, created a computer program to analyse animal motion and determine how fast large dinosaurs could move. Writing in the science journal Nature, they calculated that two-legged Tyrannosaurus rex would have needed impossibly massive leg muscles to generate enough force to support its huge body at a very fast running pace. Reuters