Upper Darriwilian (Middle Ordovician) graptolite biostratigraphy and correlation of the Krapperup drill core, Scania, Sweden

The Krapperup drill core from Scania (Skåne), southern Sweden, includes one of the most important graptolitic Darriwilian (upper Middle Ordovician) successions of Baltica. Only some intervals have been documented previously and especially the uppermost part of the succession has been completely unknown. A fairly complete succession of mid- to late Darriwilian age provides insight into the early evolution of the axonophoran (biserial) graptolites and demonstrates a distinct biogeographical faunal differentiation during this time. Graptolites from the mid-Darriwilian Holmograptus lentus and Nicholsonograptus fasciculatus biozones are discussed and important specimens and species from the Krapperup drill core are illustrated. Ekstroemograptus inexpectatus n. gen., n. sp. from the Holmograptus lentus Biozone is described as new.