(The narwhal) tusk, it turns out, forms a sensory organ of exceptional size and sensitivity, making the living appendage one of the planet's most remarkable, and one that in some ways outdoes its own mythology.William J. Broad, 12/13/2005 NYT
The find came when the team turned an electron microscope on the tusk's material and found new subtleties of dental anatomy. The close-ups showed that 10 million nerve endings tunnel from the tusk's core toward its outer surface, communicating with the outside world. The scientists say the nerves can detect subtle changes of temperature, pressure, particle gradients and probably much else, giving the animal unique insights.
Yesterday I went to the dentist and it got me thinking about about narwhals, the creatures with the most sensitive teeth on earth.