Narwhals, Monodon monoceros, are toothed whales that live mostly in Arctic coastal waters and ... Many adult males wear duelling scars from these encounters and some animals have been found with tusk ...

Caption Like walruses and elephants, male narwhals (Monodon monoceros) grow tusks; these are modified teeth. In narwhals, the left tooth erupts from their head, reaching more than 8-feet-long in ...