FOR you and me, it鈥檚 a humble U-shaped bone above the larynx that helps us chew and keeps our tongues in place. But for whales, it鈥檚 the key to getting around. Joy Reidenberg, a comparative anatomist at the Mount Sinai School of Medicine in New York, has found that these giants could not roam the seas as they do without a bone called the hyoid.
When Reidenberg started thinking about how whales swim, she realised that the hyoid might not be an adaptation for feeding, as some anatomists had thought. Though the tail is what drives a whale forward, its up-and-down motion actually starts with the head, powered by muscles attached to the enlarged hyoid. 鈥淭heir locomotion is really a body wave,鈥� says Reidenberg, who presented her results earlier this month at the Experimental Biology 2006 meeting in San Francisco. 鈥淭he hyoid has become a locomotor bone,鈥� she says.
