Tyrannosaurus rex dinosaur, the giant prehistoric predator, was even bigger and heavier than it was estimated previously, a new study found.
The finding was contained in a study published Wednesday in the scientific journal PLoS ONE.
Using three-dimension scanning and computer modeling, researchers analyzed five skeleton fossils of T. rex dinosaur, including "Sue", the largest and most complete T. rex specimen ever found.
The analysis tipped the scale of "Sue" at 9 ton, some 30 percent more than it was expected.
"At their fastest, in their teenage years, they were putting on 11 pounds or 5 kilograms a day," said John Hutchinson of the Royal Veterinary College in London, who co-led the study.
The larger body mass indicated the better agility and the stronger lower-leg muscles of the ancient monster, said the researcher.
"Sue" could have a top speed of about 10-25 miles per hour when it ran on the Great Plains of North America 67 million years ago, Hutchinson suggested.