Dental researchers discover purpose of narwhal horn
16 December 2005
by Carina
Lee
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The purpose of the 2.4 metre tooth extending from the narwhal's head has been finally explained by dentists. Clinical instructor in restorative dentistry, Dr. Martin Nweeia of the Harvard School of Dental Medicine, has revealed that the 2.4 metre tooth extending from the narwhal's head has hydrodynamic sensory functions including tactile sensory abilities. The central nerve of the tooth possesses a network of tiny nerves connecting to the tooth's outer surface. While appearing solid and rigid upon first glance, the tooth is actually like a sensitive membrane. It can detect temperature changes in the water, pressure, and particle gradients such as water salinity. Nweeia realised that the tooth contained senses but asked "Why would a tusk break the rules of normal development by expressing millions of sensory pathways that connect its nervous system to the frigid Arctic environment?" "Such a finding is startling and indeed surprised all of us who discovered it," he told Harvard Press. Previous reports and studies have found other theories that are different to this one. One theory is that the male narwhals use the tooth to display aggression and another suggests that the tooth is a secondary sexual characteristic. The natural habitat of the narwhal is the Atlantic portion of the Artic Ocean. Its ice-cold environment is one of the causes of difficultly while studying these species.
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 Dentists have discovered that the narwhal's horn is filled with sensors to help it navigate the sea  |
Related Links
Original abstract from Harvard
Nature
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