2004 Denver Annual Meeting (November 7–10, 2004)

Paper No. 15
Presentation Time: 11:45 AM

THE PERILS OF PREDATION FOR TERRESTRIAL GASTROPODS


WALKER, Sally E., Department of Geology, University of Georgia, Athens, GA 30602, swalker@gly.uga.edu

When the Rev. William Buckland threw a bone to his imported hyena at an English zoo, he was one of the first to experiment with terrestrial predators to solve a forensic puzzle: can the type of predator be deduced from dinner remains (i.e., death assemblages)? Unlike Buckland, few have asked the same question for invertebrate death assemblages found in terrestrial ecosystems. Gastropod death assemblages from terrestrial locales provide a wealth of potential paleoecological data; and yes, these assemblages entomb a predatory record of noshing on shells through time.

The insular gastropod, Cerion, for example, has had a static morphological history since its inception 125K years ago in the Bahamas archipelago, yet has suffered at the jaws, claws, and beaks of predators throughout its history. This lack of morphologic response is puzzling given that beetles, land crabs, rodents, and birds find Cerion a culinary delight as judged by their predatory remains on Cerion shells (i.e., peeled, drilled, fragmented, and repaired shells). However, the interpretation of who is the hunted from Cerion shells is not so straightforward: terrestrial hermit crabs occupy abandoned Cerion shells, and these hermits in "Cerion clothing" are, in turn, preyed upon by similar predators. Thus, for terrestrial gastropod death and fossil assemblages from tropical habitats, the predatory record archived on these shells is subjected to the Red-Riding-Hood paradox. This paradox needs to be solved first, before evolutionary predator:prey studies are conducted for terrestrial gastropods in tropical/subtropical paleoecological and archaeological deposits.