ONE of the oldest arm bones ever has been discovered. It belonged to an ancient amphibian, suggesting that forelimbs developed to help animals pop their heads out of water, long before they took their first steps onto land.
Exactly how and when fish fins evolved into limbs remains unclear. The humerus fossil was part of a 365-million-year-old amphibian fossil discovered by Neil Shubin, a palaeontologist at the University of Chicago, and his team. The bone was hinged to the shoulder joint in a peculiar way consistent with it being powered by heavy muscles to move the animal up and down,…
