While the adult tyrannosaurs used their strength and their enormous size to kill large prey , the younger ones used their agility and speed to hunt smaller prey, according to a study by the University of Ohio (USA) published in the journal Journal of Vertebrate Paleontology . ? It is one of the secrets of the success of these dinosaurs: groups of different ages did not compete with each other for food because their diet changed as they grew ,? explains paleontologist Lawrence Witmer.
Witmer and colleagues' conclusions are based on detailed analysis of a 70 million-year-old skull belonging to a very young specimen – 2 to 3 years old – of a species of dinosaur from Mongolia called Tarbosaurus bataar , considered the closest relative of Tyrannosaurus rex . Analysis of the skull reveals changes in the structure that suggest that the young tyrannosaurs had a different lifestyle than the adults. "He was probably already a skilled hunter, although instead of using brute force he used his speed and agility," says Witmer.
