Tyrannosauroids were the largest predators of Asia and North America during the Cretaceous, and the intervening 65 million years have seen little diminution in this clade.  In North America, tyrannosauroids (with the notable exception of the errosaurine tyrannosaurs) are restricted to the southern portions of the continent, well away from frigid weather.

ERROSAURINAE

    Unlike most large dinosaur groups, tyrannosauroids did not suffer unduely during the last Ice Age.  These dinosaurs evolved from small, feathered coelurosaurs, and retained fluffly coats as chicks.  When the glaciers advanced across North America, a group of neotenous, dwarf  tyrannosaurs, the errosaurines, quickly adapted to the new conditions.  These gaudily plumed, long-legged predators hunt across North America, from just south of the Arctic circle to the vast praries of the American northwest.
 

(Text by Daniel Bensen)

SAMPLE TAXA:

•  Probactyrannus gracilis
•  Phobotyrannus rubustus
• Volleur
• Thunderbird

 

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