Could Tyrannosaurus rex reach his mouth with his arms

A.� No, in fact T rex couldn't extend its elbow could not be extended much beyond a 90-degree angle.

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Q.� How long was T rex's arm

A.� About a metre long, almost the same length as a humans, with two claws. It was much thicker than a humans though.

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Q.� So what were they used for

A.� This question has puzzled palaeontologists for nearly a century. There are several theories, including, that they were used for grasping prey or that they helped T rex back on its feet after a fall.

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Q.� What about the push up theory, does this theory stand up

A.� Not really. The theory, that T rex could use its arms as an anchor to stop sliding forward while it used its legs to push itself upright, isn't supported by the evidence. The arms were overall too weak and limited in their movement.

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Q.� So how did T rex get back up after a fall

A.� It relied heavily on its tail as a counter balance. As the prone dinosaur moved its hind limbs under its body into a standing position the tail would have helped to keep the centre of balance back on the body.

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Q.� Could they lift things with their arms

A.� Although analysis of the arm bones suggest that they were strong and capable of lifting heavy things, they had very limited movement and weak wrists, so they probably weren't much use overall for lifting.

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Q.� So does any one know what T rex arms were used for

A.� Not conclusively, and we probably never will know.

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However the fact that osteological evidence suggests that they often were broken, and so presumably out of use for long periods while the break healed, points to the possibility that they weren't really used for anything essential. T rex certainly seems to have got along fine, small arms or not.

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by Lisa Cardy