This one-ton turtle once ruled South America’s rivers — until a changing planet proved too much for even the largest ...

Humongous Turtle Shell Unearthed. This shows an 8-million-year-old turtle shell that measured nearly 8 feet (2.4 meters) was discovered in Venezuela.

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 ...