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 ...

Feb. 13 (UPI) --The remains of an extinct giant turtle species suggest the reptile exhibited sexual dimorphism, with males boasting horned shells and females growing hornless shells. The turtle ...

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, ...