Stomatopods (mantis shrimps) are important predators in Recent tropical shallow-water communities. Despite a long geological history, they are poorly preserved as fossils, and traces of their predation have never been identified from the fossil record. Here we report on Plio-Pleistocene gastropods (mostly Strombus) from Florida with distinctive holes “punched” into their body whorls. The similarity of these holes to holes punched into live gastropods by Gonadactylus implicates gonodactyloid stomatopods as the predators that made them. Recent gonodactyloids break gastropod shells as thick and thicker than those of the Plio-Pleistocene strombids that were punched. Because our data underestimate the incidence of stomatopod predation, the frequency of holes in these strombids (8–13 percent) suggests that stomatopod predation may be of considerable importance in the ecological and evolutionary history of tropical benthic assemblages