The specific features of the Gülüç section (lithological changes, condensation, stratigraphic gap, change in graptolite diversity) are related to the global model of Silurian T–R cycles. | Silurian graptolite, conodont and cryptospore biostratigraphy of the Gülüç section in Ereğli, Zonguldak Terrane, NW Anatolia, Turkey