NASSARIID GASTROPODS AS DESTRUCTIVE AGENTS IN PRESERVATION AND FOSSILIZATION OF MARINE FISHES

Experimental investigations on the feeding activity of the gastropod N assarius moestus in intertidal environments in the Sea of Cortez (Gulf of California) show them to be effective agents influencing processes of marine fish taphonomy. Time-lapse documentation reveals that poten tial whole-body preservation of fish carcasses is largely prevented th rough the rapid destruction of soft tissues, muscles, and ligaments, f ollowed by disarticulation and subsequent disassociation of skeletal e lements. Dissociated bones are subject to differential dispersal throu gh hydrodynamic transport and physical wear through abrasion. Transfor mation of whole-body carcasses into thoroughly defleshed and disarticu lated skeletons by large groups of scavenging snails was commonly obse rved to take place within one tidal cycle. The loss of information dur ing taphonomic processes via destructive biological agents may ultimat ely bias the fossil record in a significant way and thus have implicat ions for the paleoecological interpretation of fossil teleost assembla ges.