Unicorns of the Sea

The narwhal has been the topic of speculation for hundreds of years. In medieval times, its horn was sold as a unicorn horn to royalty, and was immensely valuable. It is even said that Austrian lord Kaiser Karl paid off a large national debt with two tusks. Below is a picture of a ceremonial mace made with a tusk. Though science now knows that the owner of the horn is far from a unicorn, until recently they knew more about what the purpose of a unicorn's horn than the one found on a narwhal. What is known is that the tusk of the narwhal is one of two teeth. The tusk is most commonly found on males, and grows six to nine feet in length. Though it is usually males who have the tusk, there are also occasionally females with that feature. Another mutation, one which only approximately one in five hundred whales have, is for both teeth to be elongated into tusks. This is shown in the middle whale depicted in the picture beneath the mace.

Now, scientists have finally found out why the narwhals have their fascinating teeth. Several of the speculations over the years were that it was used as a spear for fishing, it was used as a lance in dominance or defense, or that it was used to spear breathing holes in the ice. Now, however, it has become evident that the tusk is actually a super-sensitive sensory organ. The horn has millions of small nerve endings that reach out from the inside of the tusk to the water. The tusk can likely be used to sense changes in water temperature, pressure, and more. This also explains why the whales sometimes rub their horns against each other in a behavior known as tusking. Look here for more about narwhals.