NEW ORLEANS -- It's a marvelously ugly beast, with spiked and ridged armor, a sharply hooked beak, a fishing lure in its mouth and a nasty bite. But the alligator snapping turtle's hard shell holds ...

Cartoons often suggest turtles wear shells like removable armor. Those stories show turtles stepping out, swapping shells, or treating them like clothing. Biology disagrees. A turtle shell is not an ...