Scientists have discovered one reason why Tyrannosaurus Rex dinosaurs were so bad-tempered and fearsome - they suffered from gout.

Their appetite for red meat is believed to have led to the condition which makes movement painful.

The discovery was made by American scientists examining the right forearm of a T-Rex, popularly known as Sue, found in Dakota.

They reported in Nature magazine that they had found the T-Rex had bone scars characteristic of the disease, which is caused by the formation of needle-shaped crystals of uric acid in the joints, leading to erosion of bones.

Team leader Dr Bruce Rothschild, of the Arthritis Centre of North-east Ohio, said: ''Although dehydration (reported in reptiles) and renal failure (reported in birds) could be contributing factors in Tyrannosau-rus Rex, a factor in humans is diet, by the ingestion of foods with a high purine content.''