Previous work has suggested that escalation may have characterized the history of the naticid gastropod predator-prey system, based on apparent increases in drilling frequencies and the occurrence of antipredatory adaptations among prey. This hypothesis is evaluated based on a comprehensive survey of predation on molluscs from the Upper Cretaceous through lower Oligocene formations within the US Gulf and Atlantic Coastal Plain. Contrary to the prediction based on the hypothesis of escalation, no temporal trend of increasing stereotype of drillhole site occurred. However, significant increases in prey effectiveness occurred between the Cretaceous and Oligocene. This pattern characterizes entire faunas as well as individual prey taxa that were consistently heavily drilled.