This study deals with Upper Ordovician bivalves (Tretaspis series, stages 4c- 5b, Upper Caradocian and Ashgillian) of the Oslo Region. Most of the fossils are poorly preserved or incomplete. Twenty-eight species and fifteen genera are identified and compared with previously described species from other regions. The specimens are not systematically collected, but are sampled from different districts.
Upper Ordovician bivalves from the Oslo Region, Norway