CHANGES IN ABUNDANCE OF PREDATORY GASTROPOD FAMILIES IN NEOGENE CARIBBEAN MOLLUSCAN COMMUNITIES

The decrease in primary productivity associated with the closure of the Central American Seaway led to a decrease in the abundance of predatory gastropods. However, drilling intensity on bivalve prey actually increased during this time. In order to make sense of these seemingly conflicting results, we quantified the relative abundance of several predatory gastropod families over the past 11 Ma. Preliminary results show a significant decrease in the relative abundance of naticid gastropods towards the Recent, with a concurrent increase in the relative abundance of muricid gastropods. The observed changes in rank abundance of predatory gastropod families is a reflection of habitat change; muricid gastropods are more common in reef environments that increased greatly in size and geographic extent in Caribbean nearshore ecosystems during the Late Pliocene. Thus, although the large-scale trend is towards fewer predators, in certain habitats predation continues to occur at high rates, but is carried out by different predators.