RAHMAN, Y.J.*; DROSER, M.L.; Univ. of California, Riverside; Univ. of California, Riverside: Ecology through Time: Studying a Guild from a Paleoecological Perspective

The study of ecological change through evolutionary time has often proceeded from a taxonomic standpoint rather than a functional ecological one. However, changes in taxonomic composition are not sufficient to describe ecological change within communities, because taxonomic lists often do not take into account issues of abundance and dominance. Members of a guild have similar ecological characteristics, but members of a taxon do not necessarily. Therefore, studying guilds within communities gives a more complete picture of community dynamics than merely studying taxa. While paleoecologists commonly collect community-level data, study of the distribution and ecology of specific guilds has proceeded at a slower rate. This study examines the paleoecology of the guild of encrusters, within the context of shallow marine environments. Encrusters are suspension-feeding organisms that live permanently attached to a substrate. As a group, they are remarkably diverse, containing representatives of every major marine invertebrate phylum. Despite the abundance and wide distribution of both live and fossil encrusters, they are often overlooked in terms of ecological importance. The Plio-Pleistocene record of California provides ample opportunity for study of the role of encrusters in shallow marine communities. With data from this time period, the functional ecological approach allows one to examine differences in encruster distribution, abundance, and substrate usage among various sites. In future work, such data could be correlated with environmental changes.