snapping turtle vs. alligator snapping turtle

either of two large, edible, freshwater turtles of the family Chelydridae, of North and Central America, having a large head and powerful hooked jaws, especially the common snapping turtle, Chelydra serpentina.

a large American snapping turtle, Macroclemys temmincki, having three prominent ridges on its shell and a wormlike process on the floor of the mouth used to attract prey.