Marine bivalves Septimyalina sublamellosa (Etheridge 1878), Septimyalina lamellosa (de Koninck 1842), Septimyalina minor (Brown 1841) and Posidonia becheri Bronn, 1828 are described from the Visean-Namurian transition of Zonguldak coal basin, Northwestern Turkey. Macroinvertebrate fossils are rare in the Lower Carboniferous of the Zonguldak coal basin and only a few shallow marine forms of Myalinidae and Posidoniidae families are present. Their palaeobiogeographic distribution delineates a seaway from Britain to the Black Sea coast during the Carboniferous.
OKAN, YAVUZ and HOŞGÖR, İZZET (2007) "Late Visean–Early Namurian Bivalves From the Zonguldak Coal Basin, Northwestern Turkey," Turkish Journal of Earth Sciences: Vol. 16: No. 2, Article 5. Available at: https://journals.tubitak.gov.tr/earth/vol16/iss2/5