Scott Persons of the University of Alberta said the 23-foot-long Carnotaurus had a huge tail muscle he believes made it one of the fastest-running hunters of its time.
A close examination of fossil tail bones of Carnotaurus showed its caudofemoralis tail muscle had a tendon that attached to its upper leg bones that pulled the legs backward powerfully to give the carnivore more power and speed in every step, a university release reported Friday.
Using 3-D computer models, Persons determined the tail of Carnotaurus had a series of tall rib-like bones that interlocked with the next pair in line, supporting the huge muscle.
The interlocked structure of the tail did present one drawback: the tail was rigid, making it difficult for the hunter to make quick turns.
However, Persons said, what Carnotaurus gave up in maneuverability it made up for in straight-line speed.