How do narwhals make their tusks?

Elephants, rhinos and walruses all have these long, protruding teeth. But this one is different from any other tooth you've ever seen. Contemplate your own teeth for a second. We usually only think about them when there's something wrong -- a chip, a cavity, discoloration. read more

It is almost always the elongated upper left canine tooth which grows through the upper lip of the male narwhal. Females only rarely have a tusk and, if they do, it’s much shorter than what is found on the male. read more

Often dubbed the unicorns of the sea, narwhals are strange and beautiful creatures with long tusks protruding from their heads. Members of the population of more than 80,000 can weigh up to 4,200 pounds and grow as long as 17 feet in length. read more