Limpets

First off I want to clarify what limpets are (because quite frankly I didn't know what these were called before this post), please see picture below.

Now as anyone who likes to collect seashells can tell you limpets have very pretty and interesting shells, but what they probably won't be able to tell you is that:

A) They are a species of snail.

B) They actually evolved from several different gastropod ancestors (they just have similar shells).

Also (and this is my favorite fact of all time about limpets) limpets have past spiders in the manufacturing of the strongest biological material. Spiders silk can withstand about 4 GPa's (gigapascals: a unit of pressure that has replaced psi in various countries), and limpet teeth can withstand about 4.9 GPa's.

Limpet Teeth: 

Limpet Underview: