Naticid Cannibalism in the Carolinas

Approximately two-million years ago a large extinction event dramatically changed life in the western Atlantic Ocean. The extinction occurred in two pulses and likely resulted from changes to primary productivity following the uplift of the Isthmus of Panama, which shut off the exchange of nutrients between the Pacific and Atlantic Oceans. Using fossil assemblages in, and museum collections from, North and South Carolina, we are studying how the molluscan fauna (snails and clams) responded ecologically. Predation is one of the most important ecological interactions and can influence the structure (e.g., species presence/absence, relative abundance) of the entire community. Interactions between predators can thus be of great importance especially when they eat each other, as is the case with naticid gastropods (pictured above). In order to better understand the changing ecological dynamics across the extinction boundary, we are studying how cannibalism changed by using traces (the drill hole in the smaller specimen above) of the predatory interactions. By understanding how communities have changed in the past, we hope to better understand how communities today might change as we move into an uncertain future.