We detected evidence of predation by the Sonora mud turtle (Kinosternon sonoriense) on the Arizona alligator lizard (Elgaria kingii nobilis) and the ground snake (Sonora semiannulata) at Montezuma Well, Yavapai County, Arizona. Lizards have not been reported in the diet of K. sonoriense, and saurophagy is rare in turtles of the United States, having been reported previously in only two other species:, the false map turtle (Graptemys pseudogeographica) and the eastern box turtle (Terrapene carolina). While the diet of K. sonoriense includes snakes, ours is the first record of S. semiannulata as food of this turtle. Ophiophagy also is rare in turtles of the United States with records for only five other species of turtles. Given the opportunistic diets of many North American turtles, including K. sonoriense, the scarcity of published records of saurophagy and ophiophagy likely represents a shortage of observations, not rarity of occurrence.