London: Tyrannosaurus rex and its relatives were more intelligent than previously thought and hunted in gangs which included young and older members, Palaeontologists claimed.

According to them, T-rex was being popularly depicted as a dangerous but dim-witted loner; this is a myth that has grown up because for many years their fossil skeletons tended to be found on their own.

Lead researcher Prof Philip Currie said they found more possible evidence of social behaviour among tyrannosaurs on a previous expedition in Canada. At a site on the Red DeerRiver, his team uncovered bones of up to two dozen specimens.

There was insufficient evidence then to prove the dinosaurs were from a single group, but several of the Gobi Desert skeletons were found lying side-by-side in the same rock layers, implying that they died together, he says.

Most experts have assumed that pack hunting evolved with the rise of mammals. Dinosaurs were not thought to have had enough intelligence to behave like modern-day wolves.

But, according to Prof Currie, from the University of Alberta, tyrannosaurs had all the necessary qualifications for pack hunting, including speed, keen senses and a highlydeveloped brain.

Further research involving CT scans of tyrannosaur skulls indicated highly developed senses for hunting, and enough brain power for co-ordinated pack behaviour, according to the palaeontologists.

They believe tyrannosaurs probably hunted in groups with adults and juveniles adopting different roles. The swifter and more agile young dinosaurs would have chased down potential prey, leaving the adults to deliver crushing fatalbites.

"Tyrannosaurids, I believe, were far more complex and more dangerous than we ever could have imagined. I believe these tyrannosaurids hunted in deadly, bloodthirsty packs," said Prof Currie, whose theory and research are the subject ofa new documentary film, Dino Gangs.