The scaly-foot gastropod (Crysomallon squamiferum) is one badass deep sea snail. Not only does it live in the foot of black smokers at the Kairei hydrothermal vent field, with temperatures reaching 725 °F, it is also tough as nails (snails, nails, get it?)
Now, scientists have figured out why their exoskeleton is so tough: it's got iron.
Crysomallon squamiferum was discovered back in 1999, over two miles below the central Indian Ocean, deep within hydrothermal vent fields. Fluids in these vents are high in sulfides and metals, which the snail incorporates into its shell. The gastropod’s shell has three layers: a highly calcified inner layer, a thick organic middle layer, and an outer layer that is fused with granular iron sulfide. It is unlike any other known natural or synthetically engineered armor.