The newly-discovered dinosaur species lived in what is now Mexico during the Campanian age of the Cretaceous period, some 72.5 million years ago.

Named Labocania aguillonae, the ancient predator was at least 6.3 m (21 feet) in length — relatively small by tyrannosaur standards.

“Tyrannosaurs dominated as apex predators in the Late Cretaceous of western North America (Laramidia),” said Dr. Héctor Rivera-Sylva of the Museo del Desierto and Dr. Nicholas Longrich from the University of Bath.

“During the Cenomanian and Turonian ages (100 to 89 million years ago), tyrannosaurs were relatively small, unspecialized, and low in diversity.”

“By the Campanian age (83 million years ago), however, they had undergone a major radiation, diversifying and producing larger, more specialized forms.”

“The Labocania clade dominated southern Laramidia at a time when the north was dominated by daspletosaurins and albertosaurines,” they added.