Scientists place dinosaurs first in race of fastest two-legged creatures

It was the biggest meat-eating animal to walk on land and now scientists have found that the fearsome Tyrannosaurus rex could run as fast as a professional footballer.

A computer simulation of the way T. rex moved based on its anatomy and muscles has revealed that the dinosaur could probably reach a top speed of about 18mph - fast enough to catch Cristiano Ronaldo.

The study investigated five meat-eating dinosaurs to see if their sprinting abilities were as good or better than present-day animals, including humans.

The scientists found that the smallest dinosaur in the group, a chicken-sized creature called Compsognathus, had a top speed of 40mph, making it the fastest-ever land animal on two legs.

Bill Sellers of Manchester University said the findings were the result of a supercomputer analysis of the way present-day animals, such as a 30kg emu or a 65kg ostrich, used their muscles and skeleton to walk and run.

In the past, scientists have assumed that bigger animals moved in much the same way as smaller animals but the latest study does not make this assumption, Dr Sellers said.

"Previous research assumed that two-legged dinosaurs were little more than big chickens. It relied on data from living bipedal models to provide clues as to how fast dinosaurs could run," he said.

"We let the computer come up with a model of locomotion. Our research involved feeding information about the skeletal and muscular structure of the dinosaurs directly into the supercomputer so it could work out how the animals were best able to move," he said.

One of the biggest surprises was the top speed of Compsognathus which at 3kg weighed little more than a large bag of sugar. "People describe it as looking like a chicken but it's a poor description. It's a very athletic animal - it was more like a 3kg roadrunner," Dr Sellers said.

"We were a little surprised at just how fast it came out in the computer model," he said.

Philip Manning, the joint author of the study, which has been published in the journal Proceedings of the Royal Society B, said that there have been many attempts at gauging the top speeds of dinosaurs but none has approached the problem in such as precise way using a supercomputer model.

"The figures we have produced are the best estimate to date as to how fast these prehistoric animals could run," Dr Manning said. "Since the movie Jurassic Park, scientists have questioned the speed of these dinosaurs and some have wondered whether Tyrannosaurus could have run at all," he said. "Our research, which used the minimum leg-muscle mass T. rex required for movement, suggests that while not incredibly fast, this carnivore was certainly capable of running an would have little difficulty in chasing down footballer David Beckham, for instance," he added.