Vermiforichnus borings from the Ordovician of central Wales

The epizoan Vermiforichnus Cameron (1969b) from the Upper Ordovician (Caradoc) of the Berwyn Hills and the Welsh Borders is host-specific, occurring in association with the strophomenid Macrocoelia and the orthid Heterorthis. The spionid polychaete probably responsible for the production of the Vermiforichnus borings inhabited both live and dead individuals. In live individuals Vermiforichnus was located at the anterior margin and oriented perpendicular to the commissure, this position affording both a means of protection and a more efficient feeding position. In dead individuals population density was lower and the borings were randomly oriented. Vermiforichnus was restricted to inner—outer sublittoral environments and, as such, is a useful palaeoenvironmental guide.