X-rays add new twist to narwhal's spiral tusk

A recent study published in the journal Nature Communications reveals a surprising discovery about narwhal tusks. These iconic spiral-shaped teeth, long associated with unicorn horns and magical healing properties in medieval times, have been found to have an unexpected internal spiral structure. This finding comes from a CT scan of a narwhal tusk, conducted by researchers Adrian Rodriguez Palomo.

Inuit legend suggests that a woman was transformed into a narwhal after being dragged into the ocean by a harpoon rope, with her twisted hair becoming the animal's tusk. However, the tusk is actually a canine tooth from the left upper jaw of male narwhals, emerging when they reach two or three years old. Narwhal tusks can grow up to 1.5 to 2 meters long, though some males may have two long spirals or none at all.

Scientists have long debated the exact purpose of these tusks, which primarily seem to serve no vital function for survival. Females rarely develop tusks, and those that do have smaller, less spiral ones. Despite their lack of necessity, males often outlive females. The main theory is that the tusk evolved through sexual selection as a symbol of social status.

Interestingly, the new research suggests that in addition to the main spiral, narwhal tusks possess a second internal spiral that runs in the opposite direction. This finding adds a new twist to our understanding of these fascinating creatures and their unique anatomical features.