Tyrannosaurus rex
One of the greatest carnivores - though not the largest - ever to have walked the Earth, Tyrannosaurus rex (or T-rex) ruled North America during the late Cretaceous period, some 68-65 million years ago. The massive skull of this mighty theropod dinosaur measured 1.5 metres and was balanced by a long heavy tail. The jaw, filled with huge, saw-edged teeth could deliver a devastating bite. Top predator or mighty scavenger, the 'tyrant lizard king' was without doubt a dinosaur to be feared. Thirty specimens have been recovered, some of which (such as those named Sue, Stan and the juvenile Jane!) are almost complete.