It's a long-held idea that turtles can tuck their heads into their shells when threatened. But is it true? And is this protective trick why turtles the world over have shells today? The answer is that ...

A sea turtle’s shell is living bone fused directly to its spine and ribs. It is not a detachable shield or an external case, as certain quirky cartoons have shown. The shell grows with the turtle, ...

One of the most telltale features of a turtle is its protective shell, and regardless of the species, most turtle shells are discernably similar. Despite what you might see on cartoons, a turtle’s ...