First record of the trace fossil Renichnus arcuatus Mayoral, 1987 in the Pliocene of Sidi Brahim (Lower Chelif Basin, NW Algeria)

A vermetid etching trace, Renichnus arcuatus, has been described from the outer surface of a single right valve of Hyotissa hyotis from the Lower Chelif Basin, Algeria. This is the first record of vermetid etchings from the Pliocene of the Mediterranean Sea's southern coast. The vermetids responsible for the etchings used bivalve shells as a hard substrate for attachment. The vermetids used mucus nets to feed and they may have benefitted from the feeding currents of the host if they colonized a living bivalve. The palaeogeography of similar etching records indicates that vermetids were common in the Mediterranean region in the Pliocene.