How cold-blooded dinosaurs made themselves sound sexy

THEY BELLOWED like bulls, rutted like reindeer and preened themselves like peacocks. Far from being cold-blooded reptiles, dinosaurs were emotionally complex animals.

Professor Neil Alexander, a world authority on animal anatomy at Leeds University, told the British Association yesterday that many of the unusual structures possessed by male dinosaurs were there to either attract females or fend off sexual rivals.

Male hadrosaurs had metre-long bony crests extending from their nostrils and over their heads effectively to extend the nasal chamber into a trombone- like musical instrument. "It made the male voice sound ultra-grown-up and to a female hadrosaur that was very sexy," Professor Alexander said.

Diplodocus had a tapered tail as long as a cricket pitch which the dinosaur could crack like a whip. Just as two stags bellow to assess each other's physical prowess, male diplodocus rivals would crack their tales as a test of stamina, Professor Alexander suggested.

Even dinosaur footprints have revealed the sophistication of their locomotion, said David Norman, a palaeontologist at Cambridge University who was an adviser for a new BBC series on the life and behaviour of dinosaurs to be screened in the autumn.

"If you know the size of the foot, you can relate that to the height of the hip and if you know the distance between the footprints you can estimate the stride length and ultimately you can work out from that an approximation of the speed with which the animal was moving," Dr Norman said.

Although most fossilised tracks were produced by walking dinosaurs, some footprints have been discovered which show the animals to be running at speeds that rival the fastest human sprinters.

James Farlow, a dinosaur scientist at Indiana-Purdue University, said one set of fossilised footprints show that dinosaurs stalked their prey just like lions and tigers.