A dinosaur who was a speedy hunter

Carnotaurus, a seven-meter-long flesh-eating dinosaur with a huge tail muscle, was one of the fastest hunters, says new research.

A scrutiny of the tail bones of Carnotaurus showed its caudofemoralis muscle had a tendon attached to its upper leg bones. Flexing this muscle pulled the legs backwards and gave it more power and speed.

So says paleontology graduate student Scott Persons from the University of Alberta.

In earlier research, Persons found a similar tail-muscle and leg-power combination in the fearsome T. rex. 

Persons' examination of the Carnotaurus tail showed that along its length were pairs of tall rib-like bones that interlocked with the next pair in line, reports the journal Public Library of Science ONE.

Persons found that the unusual tail ribs supported a huge caudofemoralis muscle.

The interlocked bone structure along the dinosaur's tail did present one drawback: the tail was rigid, making it difficult for the hunter to make quick, fluid turns.

What Carnotaurus lost in maneuverability, it made up for in straight  speed. For its size, Carnotaurus had the largest caudofemoralis muscle of any known animal, living or extinct.