The big tail that Tyrannosaurus Rex had, was helping it run much faster than scientists estimated, making it the fastest hunter of its time.University of Alberta
graduate student Scott Persons, discovered that Tyrannosaurus Rex was not at all a slow Cretaceous creature, whose tail only served as counterbalance for its big head.
Persons' research shows that T. Rex was very athletic and its powerful tail muscles made it the fastest moving hunter of its era.
The paleontology student at the University of Alberta started his research by comparing the tails of reptiles nowadays – like Komodo dragons and crocodiles, to the tail of the T. Rex.
In today's big reptiles, the biggest muscles in the tail – the caudofemoralis muscles, are linked to the upper leg bones, and they facilitate a fast forward movement.
The tail structure of the T. Rex however, was a bit different: according to Parsons, the shape and the strength of modern reptiles and of the Tyrannosaurus Rex, are given by the rib bones attached to the vertebrae.
The difference is that the ribs of the dinosaur are located much higher on the tail, leaving much more room along the lower end of the tail, for the caudofemoralis muscles to increase their mass and expand.
T. Rex's caudofemoralis muscles were an almost unlimited source of power, and without any rib bones to limit their size, they turned the dinosaur into one of the fastest predators of its time.
Persons proved that “contrary to earlier theories, T. Rex had more than just junk in its trunk.”
He actually made extensive measurements of the dinosaur's bones and his computer model shows that earlier estimates of the muscle mass in the tail of the T. Rex were underestimated by 45 percent.
This is why many researchers believed, until now, that the Tyrannosaurus Rex had limited hunting skills and fed on animals killed by other predators.
The scavenger was believed to barely support its own weight, because of the lack of necessary muscle mass.
As for the creature's exact speed, the researchers say that it is very hard to measure, but Parsons says that it could have been the fastest animal in its ecosystem.