Alligator Snapping Turtle

Alligator snapping turtles are the largest freshwater turtles in North America and among the largest in the world. While the common snapper (found in PA) has a rather rounded, smooth carapace (top shell), the alligator snapper's shell has three large, pronounced ridges running front to back and raised plates across its massive shell. The alligator snapping turtle looks very primitive and has been called the dinosaur of the turtle world.