Babirusa: The Self-Stabbing Pig of Sulawesi

In North Sulawesi, a babirusa’s upper tusks can reach nearly 17 inches long-and that’s when they start to curl backwards, piercing straight through the animal’s own skin. The skull of a male found near the Bolaang Mongondow River in 2014 shows both tusks curved in a complete spiral, one tip so deep it gouged the forehead bone beneath. For years, people guessed these monstrous teeth must be weapons, but a live babirusa’s tusks are so brittle they can shatter in a fight. The lower tusks do line up with the upper, but attempts to clash them together often just snap them off. Wild males don’t use these ivory arcs to root or dig-if they did, the points would splinter within days. Instead, the tusks keep growing regardless of trauma, curving further until some slice into the skull-enough that researchers in 1998 photographed an adult with tusks buried an inch deep through its own face. The only thing that finally stops a babirusa’s tusks is death, when ivory growth ceases and the teeth that threatened its brain lock in place forever.