This is the VOA Special English SCIENCE REPORT.
Ancient animals called dinosaurs have captured the imagination of millions of people around the world. The huge dinosaur Tyrannosaurus rex has even been in popular American movies like "Jurassic Park." In some movies, Tyrannosaurus rex is shown running at top speed after cars and helicopters. The Tyrannosaurus in the movies is a terrible combination of speed and power.
Yet two biological scientists say this is probably wrong. They are John Hutchinson of Stanford University in California and Mariano Garcia of Cornell University in Ithaca, New York. Their research suggests that Tyrannosaurus rex could only walk slowly. They reported their findings in the publication Nature.
Mr. Hutchinson and Mr. Garcia used a biological computer model to study the bones of the ancient creature. They found that the legs of Tyrannosaurus were not strong enough for the animal to be able to run fast.
The meat-eating dinosaur weighed almost six-thousand kilograms. Mr. Hutchinson says the animal's legs would have had to be huge to enable the creature to run fast. He says its leg muscles would have had to be eighty-five percent of its total weight.
The findings of the two biological scientists conflict with current scientific information about Tyrannosaurus. Until now, scientists believed that the huge dinosaur could run up to seventy kilometers an hour. This idea has passed into popular culture all the way to the directors of Hollywood movies.
Not all scientists agree with the findings of Mr. Hutchinson and Mr. Garcia. In the last twenty years, scientists who study ancient bones have linked dinosaurs to birds. Some paleontologists believe the bird-like bones of giant dinosaurs suggest that some of these ancient creatures were fast runners. Many paleontologists continue to believe that the bone structure of Tyrannosaurus shows that it could run fast.
The debate over how fast some dinosaurs ran probably will continue for some time. The last Tyrannosaurus rex died about sixty-five-million years ago. Paleontologists can only know the giant creature from its mineral fossil remains. Tyrannosaurus always will remain a creature of popular action movies and of the imagination.
This VOA Special English SCIENCE REPORT was written by Mario Ritter.