Mystery of 'Unicorn' Whale Solved

The narwhal, known in folklore as the "unicorn whale" for its spiraling tusk, has been a mystery to scientists and traditional Inuit cultures alike, for no one could explain the purpose of the tusk. Now a researcher from Harvard says he has the answer.

The tusk, actually a tooth that grows outward from the left side of the upper jaw, can measure nearly three meters in length. Martin Nweeia, a researcher from the Harvard School of Dental Medicine, says that although the tusk appears to be a hard point used for some mechanical purpose (such as breaking through ice), it is in fact a richly-arrayed sensory organ with a relatively soft and sensitive outer sheath around a rigid core.