Which animal has the largest tooth in the entire animal kingdom? The first animal that might come to mind is perhaps a tiger or lion, and they do indeed have an impressively and intimidating set of teeth! But the animal that hands-down wins this category may surprise you: it is the beautiful, mysterious “Unicorn of the Sea”: the Narwhal!

#FunFact: The Narwhal’s Famed Horn is Actually a Tooth

--And growing up to an incredible 10 feet long, the narwhal’s tooth easily wins Largest Tooth in the Animal Kingdom!

The narwhal’s “horn” is an elongated left canine tooth, and it is most commonly found in male narwhals. Narwhals do not have any other teeth besides their two canine teeth! About 15% of female narwhals also grow a horn, and less commonly, some narwhals even grow two horns. Though long believed to be used primarily for fighting, displaying dominance, and for breaking surface ice, the narwhal’s swordlike, spiral tusk has more recently been discovered to also function as a sensory organ that helps them navigate the watery world around them.

The tusk contains living pulp and has up to 10 million nerve endings, and it helps the narwhal sense a variety of environmental conditions around them. Though researchers are still learning more about this elusive animal, it is believed that their very special tooth helps the narwhal “read” changes in temperature, water pressure, particle gradients and motion. This fascinating WWF video shows narwhals using their horns to hunt in two ways: twitching the tusk to and fro presumably to help them locate their prey, and also striking and stunning fish with their horns before eating them.

The narwhal’s horn - besides being the largest in the animal kingdom - is a truly fascinating and unique tooth. We know that narwhals use their tusks to display dominance, break surface ice, “taste” changes and chemicals in the water, find potential mates, find food, stun their prey, and navigate Arctic ice formations. Researchers are still learning about narwhals and their multi-purpose tooth, and it is exciting to think about what else we can learn about them!

Honorable Mentions:

African Elephant: Their regal tusks are actually enlarged incisors, almost a third of which are embedded in their skulls. They grow on average about 6 feet long and weigh about 100 pounds each. The longest elephant tusk recorded was a whopping 11.5 feet, and the heaviest was about 250 pounds. Though the killing of these majestic, endangered animals for the ivory of their tusks has long been largely outlawed, the cruel and barbaric practice of ivory poaching still exists to this day.

Hippopotamus: The hippo has an incredibly large mouth (about 2 feet across, and they can open their mouths a massive 4 feet wide!) and has the largest teeth contained inside an animal’s mouth. Their incisors grow up to 1.2 feet, while their lower canines reach up to 1.5 feet in length! However these teeth are also a source of ivory for which hippos have increasingly been targeted, and the hippopotamus is a vulnerable species with a declining population.