Shell repair following failed predation in two Upper Ordovician brachiopods from central Sweden

Shell repair is reported in two dorsal valves of the brachiopod Strophomena? arachnoidea Lindström, 1880 from the lower Ashgill Fjäcka Formation of the Siljan district, Dalarna. The most severe case displays a large wedge-shaped injury that cuts back about half the length of the animal. Substantial damage to the growing edge of the mantle resulted in malformation of the repaired area. The outline of the injury on the second specimen is also wedge-shaped, but of much less extent and with little disturbance of the subsequent growth pattern. Both injuries are interpreted as resulting from failed predation, with cephalopods being the most likely aggressors.