Prehistoric speedway: Super-sized muscle made twin-horned dinosaur a speedster

October 15, 2011 By Brian Murphy

(PhysOrg.com) -- A meat-eating dinosaur that terrorized its plant-eating neighbours in South America was a lot deadlier than first thought, a University of Alberta researcher has found.

Carnotaurus was a seven-metre-long predator with a huge tail muscle that U of A paleontology graduate student Scott Persons says made it one of the fastest running hunters of its time.

A close examination of the tail bones of Carnotaurus showed its caudofemoralis muscle had a tendon that attached to its upper . Flexing this muscle pulled the legs backwards and gave Carnotaurus more power and speed in every step.

In earlier research, Persons found a similar tail-muscle and leg-power combination in the iconic predator . Up until Persons published that paper, many dinosaur researchers thought T. rex's huge tail might have simply served as a teeter-totter-like counterweight to its huge, heavy head.

Persons' examination of the tail of Carnotaurus showed that along its length were pairs of tall rib-like bones that interlocked with the next pair in line. Using 3-D computer models, Persons recreated the tail muscles of Carnotaurus. He found that the unusual tail ribs supported a huge caudofemoralis muscle. The interlocked along the dinosaur's tail did present one drawback: the tail was rigid, making it difficult for the hunter to make quick, fluid turns. Persons says that what Carnotaurus gave up in , it made up for in straight ahead speed. For its size, Carnotaurus had the largest caudofemoralis muscle of any known animal, living or extinct.

Persons published these findings in PLoS ONE on Oct.14, with supervisor Philip Currie, a paleontology professor at the U of A.

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derfolo
5 / 5 (2) Oct 15, 2011
Many of us have just one question: How fast could it run?
ROBTHEGOB
not rated yet Oct 15, 2011
Fast enough. DUH.
Doug_Huffman
1 / 5 (1) Oct 15, 2011
Or not. Like avoiding a speeding race car or charging toro, keep your eyes on it and step aside at the last instant.

T. Rex with similar anatomy has been estimated from 25 mph to as high as 45 mph, constrained by similar physics, rotational inertia, to slow turns. Locomotion is essential in the feeding debate, carnivore or scavenger.
Joseph_Jensen
not rated yet Oct 16, 2011
Fascinating...

So then, why are we using their remains to power our vehicles? If they were nasty and vicious then, their lingering essence surely has a similar affect on our atmosphere. Just a quantum thought...
Parsec
not rated yet Oct 16, 2011
Fascinating...

So then, why are we using their remains to power our vehicles? If they were nasty and vicious then, their lingering essence surely has a similar affect on our atmosphere. Just a quantum thought...

Oil and natural gas mostly come from the carboniferous era, when giant forests covered the earth and the O2 percent was 27% or so. They burned and regrew, then burned and regrew for millions of years, laying down most if not all of the coal, and much of the oil. Dinosaurs did not contribute.

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