T-Rex's bite made worse by his gout

It was grumpy, loud, and carnivorous: and the classic image of Tyrannosaurus Rex, the archetypal dinosaur, may have had a lot do with its appetite, according to work by American scientists. For the "tyrant king" of the now-extinct beasts had gout, says a study of fossilised bones and joints. This would have made movement painful - just as it does for human sufferers of the condition.

And for anyone who decides that seeing its fabled grumpiness on screen (in the new Spielberg film The Lost World) is not enough, the next few months will offer the chance to buy two of the most complete T rex skeletons that exist. One, with more than 60 per cent of the bones in place, is being offered for $10m, while another - which was key in the discovery of T rex's ailment - is being auctioned in autumn in New York, with a reserve price of $1m.

Gout is caused by the formation of needle-shaped crystals of uric acid in the joints - usually, in humans, because of ineffective kidneys. Among famous sufferers was Henry VIII. Before modern medicines (which can dissolve the crystals) were available, the usual treatment was rest, in order that the crystals might dissolve spontaneously. However, it causes erosion of the bone where the crystals form - which is what Bruce Rothschild, of the Arthritis Center of Northeast Ohio, in Youngstown, noticed in the right forearm of one of the three most complete T rex skeletons (known as Sue). More studies on other bones of other skeletons confirmed signs of bone erosion peculiar to gout - which has been found in modern-day reptiles and birds, which are descended from the dinosaurs.

The question, though, is why T rex should have got gout, since it did not (as far as palaeontologists can tell) drink port or eat butter, the usual causes in those genetically predisposed to the disease. However, says Mr Rothschild, another factor is consumption of foods with high concentrations of chemicals known as purines - plentiful in red meat.

This, he notes, was "no stranger to this denizen from the Cretaceous era."

The sale of T rex skeletonshas been timed to cash in on the the Spielberg film, and could provide a useful measure of the real scientific value of dinosaur skeletons - as opposed to their value to filmmakers.

The $10m price tag placed on the first skeleton, which includes a tooth 33cm long, is almost 10 times greater than the previous top price for a fossil.