DECAPOD CRUSTACEANS FROM THE EOCENE CASTLE-HAYNE FORMATION, NORTH-CAROLINA - PALEOCEANOGRAPHIC IMPLICATIONS

Ten species of brachyuran decapod crustaceans, including four new spec ies, Matutites miltonorum Pororaria? granulosa, Eocarpilius blowi, and Glyphithyreus sturgeoni, are described from the Eocene Castle Hayne F ormation in North Carolina. In addition, claw fragments suggest the pr esence of an additional four species. Analysis of the fauna within the formation, coupled with data from the enclosing rocks, suggests an en vironment of deposition in subtropical, clear water at shallow shelf d epths. Wave and current energy were variable. Although no corpses were recognized and all the taxa were represented either by claw fragments or isolated carapaces, little abrasion or breakage was observed, whic h suggests that the material was deposited near the living site of the organisms. Many of the decapod taxa are congeneric with contemporaneo us forms from Italy and with Miocene species in Hungary. Paleoceanogra phic modeling, using the Parallel Ocean Climate Model (POCM), forced b y the GENESIS atmospheric circulation model, produces conditions of te mperature, salinity, and ocean circulation that corroborate conclusion s drawn from analysis of the Castle Hayne sediments and fauna and, add itionally, yields similar conditions for the northern margin of the Te thyan region in the Mediterranean basin. Ocean circulation patterns de monstrate the feasibility of dispersal of subtropical organisms from t he Mediterranean part of the Tethys across the Atlantic Ocean to the N orth American coastline.