Common Snapping Turtle
Chelydra serpentina

Size:  1 1/2 - 2 ft (along carapace)
Distribution:
Common statewide.  Often confused for an alligator snapping turtle, the common snapper is easily distinguished by a single row of marginal scutes, a heavily toothed tail, and the carapace is not as radically knobbed.  The common snapper is also far more active than the alligator snapper in pursuit of prey and frequently emerges from the water.  They are found primarily in shallow water where they scavenge for injured or dead fish, but may sit and wait for live fish to approach close enough to snap. 
Juvenile common snapping turtle.  Notice the single row of marginal scutes.