Gastropod predation patterns in the Eocene of Nigeria

The Ameki Foi-mation (middle Eocene) of Nigeria contains a diverse, primarily molluscan macrofauna that probably lived in a shallow-shelf marine environment. Naticids, followed by muricids, were the most abundant and most successful borcrs. Cannibalism was high among the naticids. Though small (< 10 mm) gastropods were thc most fi-equently exploited food sourcc, there is no strict correlation between predator and prey sizes. Coarseness of sculpture and shell thickness similarly did not constitute effective deterrents to borers. Comparison of the predator-pl-ey pattern in the Ameki with that of Eocene assemblages from the Paris Basin and Alabama and a Recent West African shelf assemblage shows that since the Eocene, pelecypods have replaced gastropods as the most frequently exploited food source of predatory borers, and muricids have become better represented numerically.