Tyrannosaurus Rex may or may not have been the most fearsome dinosaur that ever lived--you can also make a good case for Allosaurus or Spinosaurus--but whatever its ranking on the all-time viciousness charts,
Tyrannosaurus Rex may or may not have been the most fearsome dinosaur that ever lived--you can also make a good case for Allosaurus or Spinosaurus--but whatever its ranking on the all-time viciousness charts, this predator had one of the smallest arm-to-body-mass ratios in the prehistoric world. For decades, paleontologist and biologists have debated how T. Rex used its arms, and whether a further 10 million or so years of evolution (assuming the K/T Extinction hadn't happened) might have caused them to disappear entirely.
The Arms of T. Rex Were Tiny Only in Relative, not Absolute, Terms
Before exploring this issue further, it helps to define what we mean by "tiny." Because the rest of T. Rex was so huge--adult specimens of this dinosaur measured about 40 feet from head to tail and weighed anywhere from 7 to 10 tons--its arms only seemed small in proportion to the rest of its body, and were still pretty impressive in their own right. In fact, T. Rex's arms were over three feet in length, and a recent analysis has shown that they may have been capable of bench-pressing over 400 pounds each. Pound for pound, this study concludes, T. Rex's arm muscles were over three times more powerful than those of an adult human!
There's also a fair degree of misunderstanding about the range of T. Rex's arm motion and the