Spirolites radwanskii n. igen. n. isp.: vermetid gastropod attachment etching trace from the middle Miocene rocky coast of the Paratethys, Poland

A new ichnogenus and ichnospecies, Spirolites radwanskii, is a spiral boring recognized in large limestone clasts deposited in a Miocene cliff-foot ramp. It is characterized by a semi-circular or inverted Ω-shaped cross section, gradually increasing width, gradual entrenching in the rock from the narrower side, consistent coiling direction, steep margin from the wider side, two-order annuli, and occasional truncation of the narrower side by the wider part. It is interpreted as a boring of vermetid gastropods, similar to the recent Dendropoma. Spirolites co-occurs with the bivalve borings Gastrochaenolites, mostly G. torpedo, sponge borings Entobia, and the spionid polychaete boring Caulostrepsis, which are typical of the Entobia ichnofacies. Spirolites was produced in very shallow, clean and warm sea waters.