Ti-rex was bigger and scarier than previously thought

Tyrannosaurus rex grew in their teens, faster and was more difficult than previously thought, scientists said.

With the help of lasers and computer animation, the British and American scientists "measured" These are five-rex, including "Sue" from a museum in Chicago - which is by far the largest and most complete skeleton of this dinosaur were discovered.

The scientists concluded that Sue, who swept the Great plains of North America 67 million years ago, was heavier than nine tons, which is 30 percent higher than previously thought.

Interestingly, the smallest and youngest specimen weighed less than previously thought, which threw new light on the biology of these animals and suggests that the Ti-rex grew twice as fast at the age of 10 to 15 years than previously thought.

"In the period of fastest growth, while they were teenagers, they were given five pounds a day," said John Hutchinson told Reuters from the Royal Veterinary College in London.

"Just think how much it is meat. It's just a lot of cheeseburgers ... many small hadrosaurusa that are chewed," he added.

Hadrosaurus were herbivores and were the obvious choice on the menu of predators.

Huge appetite means that the Ti-rex had to "cover" and a large territory and that these predators were relatively rare.

Their rapid growth states, and the thought that they had a fast metabolism and that they were most likely warm-blooded animals.

Large body mass means that Ti-rex was not extremely fast, and that they were moving at maximum speed between 15 and 40 miles per hour.

"They were not super fast but they are not even pull," said Hutchinson.