Cave Elephant

Fantasy Fact: Dragons ingested platinum, which ignited gut-produced gas, allowing them to breathe fire.

Scientific Inspiration: Birds don’t have teeth, and many species rely on swallowing grit and even small stones to help grind up food in their gizzards. Dinosaur stomachs sometimes contained large stones, or gastroliths, worn smooth by grinding or exposure to digestive fluids. We can't test this directly, but the stones probably also played a part in breaking down hard food. Modern crocodiles do much the same, the stones also serving as ballast for swimming. So quite a number of animals take in minerals to use for their own purposes.

Rather more special than these examples are the elephants of Mount Elgon in Kenya. Many animals congregate around salt licks. For the Mount Elgon elephants, though, the only natural source of salt is in deep caves in the sides of the mountain. Family parties of elephants enter the caves, walk as far as 500 feet in pitch-darkness, then chip off chunks of salt-rich rock with their tusks and crunch them up.