A symbiotic relationship between Lingula and the coral Heliolites in the Silurian

Many specimens of Heliolites interstinctus from the Aymestry Limestone (Ludlovian) of the Welsh Borderlands contain borings: the most commonly associated coral, Favosites gothlandicus, does not. The only fossil preserved intact in the now sediment filled borings is Lingula sp., which occurs in life position in some 28 borings. It is concluded that in some cases the corals were still alive when the borings were occupied. It is inferred that Lingula was unlikely to have made the borings and from the morphology of the borings themselves, annelids, bivalves or cirripeds were the most likely borers. It is concluded that Lingula occupied preformed sediment filled borings, in some cases living symbiotically with the live Heliolites. It is suggested that the structure of Heliolites was less resistant to boring attack than that of Favosites