Lower Campanian siliceous sponges from epicontinental deposits of the Subhercynian Cretaceous Basin in Germany contain amygdaloidal depressions which are distinguished as a new ichnospecies of the ichnogenus Cuenulites. These bioerosion traces are interpreted as borings of semiendolithic bivalves, produced without significant rotation movement, probably mostly by chem ical action. As there are no signs of tissue reaction in the bored sponges, the structure is considered to be produced post mortem to the sponge, probably in a foreshore-shoreface setting, with redeposition offshore.