The running joke with the Tyrannosaurus Rex is that despite its gargantuan strength and ferocity, it had tiny arms which almost seem like an evolutionary mistake.
Not so much – in 1915 when paleontologist Osborn first erected the bones of the Tyrannosaurus he mistakenly substituted longer, three-fingered forelimbs to replace it’s still missing limbs.
His mistake could have been because he noticed large areas for muscle attachment, an indicator of great strength. Could be why he assumed the bigger arms.
Lawrence Lamb contested this theory stating that the T. rex’s arms were, in fact, short and two fingered.
His hypothesis wasn’t confirmed until much later in 1989 but despite their opposing viewpoints with regards to aesthetics both scientists firmly believed that though the T-Rex’s arms were tiny, they were mighty.
Eventually, the T. rex’s forelimbs were found and analysed. What they found was astounding – those tiny arms were capable of lifting up to 500 pounds and could have been used for multiple reasons including copulation, holding down prey or lifting their massive bodies up from a prone position.
Not only were their arms strong, they were extremely thick with bone which allowed them to withstand the tremendous pressure exerted from heavy lifting.
The M. biceps muscle of T.rex was 3.5 times as powerful as its human equivalent, and though they had limited range of motion (40 and 45 degrees), it only benefited them more. As scientists believe such stiffness only aided them in holding struggling prey down.
It’s safe to assume that the T.rex was engineered to be an unbeatable predator. Yet another reason we are SO thankful for that meteor.