The long tusk of the male narwhal earned these whales their fanciful nickname. But there's more to these Arctic mammals than their unique spiral tooth.
A skull found in West Greenland is proven to be the first-generation male offspring of a female narwhal and male beluga whale. The creature's unusual diet may have been a result of its strange teeth.
What can the story of a lost narwhal and his beluga family tell us about interspecies adoptions?