Iron, key to strong beaver tooth

Beavers do not brush yet their front teeth are strong enough to cut trees. This is because their teeth contain small amounts of iron that protect the enamel from wear and tear and acidic substance. Iron is present in an unstructured phase around the well-ordered "nanowires" that form the enamel's core. The find can be used in studies on tooth decay in humans. 

Source

Down To Earth, March, 2015