Answer: Snail Teeth

For years, spider silk was considered the strongest material found in nature with an incredible tensile strength on par with strands of steel wire of similar size. But a recent discovery has pushed spider silk out of the lime light and brought in a rather unlikely candidate to replace it: snail teeth.

Researchers at the University of Portsmouth studying the tiny teeth of the limpet—a type of marine snail that firmly attaches itself to rocks and scrapes algae and nutrients off rock surfaces with a ribbon-like tongue bristling with teeth—found that the teeth are incredibly strong. On a microscopic level, the teeth are composed of fibers interwoven with minerals and are so strong that as the limpet feeds, it not only scrapes the algae off the surface of the rock, but scours the rock in the process.

When subjected to the same kind of tensile stress tests that determined spider silk was such a strong natural substance, the limpet teeth showed a tensile strength higher than even the strongest known spider silk. To put the strength of the tooth material into perspective, if you scaled it up from the atomic level to say, the level where the fibrous teeth were the diameter of a strand of spaghetti, then that bit of spaghetti would be capable of holding up a compact car like a Honda Civic without breaking.