Taphonomic signatures on some intertidal molluscan shells from Tarut Bay (Arabian Gulf,Saudi Arabia)

The present contribution documented a molluscan assemblage (bivalves and gastropods) collected from the intertidal water of tarut bay,east coast of saudi arabia and assessed the degree of post-mortal alteration of the shell material. in this assemblage,bivalve shells were totally dominated by disarticulated valves and had significant taphonomic alteration in their shells. four principal taphonomic attributes were analysed: encrustation,bioerosion,fragmentation and abrasion. three types of encrusters were recorded on shells of the present study: balanoids,polychaetes and bivalves (spondylus and oysters). amongst,balanoid barnacles represented the most common encrusters that were recorded in both gastropod and bivalve shells. it was observed that each encruster attached on the host as a single epibiont and no share with other epibionts on the same host. bioerosion traces in shells were predominately those of clionid sponges and gastropods. they were represented by the ichnogenera entobia and oichnus. the presence of drill holes assigned to the ichnospecies oichnus simplex bromley,1981 were made by muricid gastropods which are common in the study area. fragmentation was mainly resulted from biological processes (bird predation) on the brittle-shelled bivalve species vepricardium asiaticum. many of bivalves were observed abraded,lacking-sheen,and showed evidence of corrosion. copyright © 2015 zoological society of pakistan.