Experts say there is enough variation in samples to argue there was also a Tyrannosaurus imperator and a regina
With its immense size, dagger-like teeth and sharp claws, Tyrannosaurus rex was a fearsome predator that once terrorised North America. Now researchers studying its fossils have suggested the beast may not have been the only tyrannosaurus species.
Experts studying remains thought to belong to T rex have suggested their variation shows evidence of not one species but three.
