THE TYRANNOSAURUS Rex was the most feared and ruthless killing machines nature ever created.
But scientists have recently been debating if the fearsome dinosaur was a scaly monster or whether they had fluffy feathers instead? Here’s what we know…
What did a T-Rex look like?
The Tyrannosaurus rex was one of the largest meat-eating dinosaurs that ever existed.
Fossils reveal the ferocious predator was around 40 feet long and up to 20 feet tall, with a powerful tail and massive skull.
Prey would have been ripped apart by its conical teeth, and scientists believe they would have been about to devour up to 500 pounds of meat in one meal.
A new BBC2 documentary, entitled The Real T-Rex with Chris Packham, sees experts re-imagine what the dinosaur would have looked like based on the latest research.
Scientists in the show claim that as well as having orange markings around its eyes - as if it had red eyebrows - the T-Rex may also have had a biological pigment that produces freckles.
While it is portrayed in Steven Spielberg’s Jurassic Park as being green and having a huge roar, some experts now believe it was instead black and produced a rumble that was barely audible.
It is thought that the creature may instead have more in common with birds, following analysis of dinosaur bones, teeth and skin.
How big were the Tyrannosaurus' arms?
The T-Rex may have been large and intimidating, but its arms were actually on the small side.
They had two-fingered forearms that would have been able to seize prey, but they weren’t long enough to stretch to its mouth.
It is thought that its teeth was used to grip prey’s flesh, and then the strong neck muscles would have been used to rip this away from the bone.
Bones have been found in the dung of T-Rex suggesting the predator crushed and broke bones as it ate.
Did T-Rex dinosaurs have feathers?
The idea T-Rex was feathered was fuelled by the discovery of Yutyrannus Huali five years ago in China.
Despite weighing 1.5 tons, the fearsome predator had feathers, a discovery which added weight to the theory its famous cousin must also have had them.
The Real T-Rex documentary agrees with this theory, but many experts insist the T-Rex really did look like the scaly killing machine familiar from films like Jurassic Park.
New fossils dug up North America and Asia have proved the T. Rex was covered in skin which looked like the scales of modern reptiles.
Dr Phil Bell, of the University of New England, New South Wales, said the ancient monster was so gigantic that feathers would have caused it to overheat.
More on dinosaurs
When was the Tyrannosaurus Rex alive?
The predator roamed forested valleys in North America during the late Cretaceous period, around 65 million years ago.
It became extinct the Cretaceous-Tertiary mass extinction, which is famed for wiping out the dinosaurs.
The extinction is through to have reduced around three-quarters of the plant and animal species on Earth and scientists have proposed this could have been caused by a massive comet or asteroid impact.