The geometry of their shells keeps turtles from getting stuck on their back.

Image: flickr/Mikhail EstevesAlthough the Teenage Mutant Ninja Turtles didn't seem to have this particular problem, it's commonly thought that once a turtle gets stuck on its back, it's pretty much doomed. While it's true that turtles, like other animals with shells, can have a hard time righting themselves when flipped over, they aren't helpless. In fact, according to these mathematicians, the domed shell of land turtles is shaped in a nearly optimal curve to help the turtle flip back over. As Donatello would say, "Turtle Power!"Geometry and self-righting of turtles. "Terrestrial animals with rigid shells face imminent danger when turned upside down. A rich variety of righting strategies of beetle and turtle species have been described, but the exact role of the shell's geometry in righting is so far unknown. These strategies are often based on active mechanisms, e.g. most beetles self-right via motion of their legs or wings; flat, ...