The correlation of Tournaisian and Visean platform carbonate successions of Britain and Ireland initially relied upon the development of coral and brachiopod zonations. However, such zones are strongly facies-controlled and are only of local to regional significance. Over recent years, emphasis has been placed upon the use of foraminifers, and notably conodonts, to define international stages. They have been studied increasingly within the Tournaisian and Visean successions of Britain and Ireland, but are of limited stratigraphical value in younger Carboniferous strata. Ammonoids (goniatites) provide the greatest biostratigraphical resolution for the late Visean, Namurian and early Westphalian stages. Some ammonoid biozones can be recognized across Western Europe and some biozones are applicable globally. However, the marine bands that contain these ammonoids may be absent towards basin margins and marine influence is lost entirely throughout late Westphalian and Stephanian times. Within strata lacking ammonoids, biostratigraphical correlation initially relied upon the recognition of non-marine bivalve zonation, but over recent decades palynomorphs (miospores) and plant macrofioras have assumed greater importance.