Why the turtle got its shell

Burrowing power, not protection may have triggered carapace evolution

Eunotosaurus africanus illustration

BIG DIG  An ancient reptile (Eunotosaurus africanus), a precursor to today’s turtles, had a body well-suited to burrowing, as illustrated here. (Another extinct reptile, Bradysaurus, is shown in the background.)

Andrey Atuchin

Turtle shells didn’t get their start as natural armor, it seems.