ABSTRACT

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.

摘要

来自瑞典南部斯堪尼亚（斯科讷）的 Krapperup 钻芯包括波罗的海最重要的笔石 Darriwilian（上中奥陶统）岩层之一。以前只记录了一些间隔，尤其是序列的最上部完全未知。Darriwilian 中晚期相当完整的序列提供了对轴突（双列）笔石的早期演化的洞察，并展示了这一时期明显的生物地理动物区系分化。讨论了来自中达里维利安 Holmograptus lentus和Nicholsonograptus fasciculatus生物区的笔石，并说明了来自 Krapperup 钻芯的重要标本和物种。出乎意料的Ekstroemograptusn. gen., n. sp。来自Holmograptus lentus Biozone 被描述为新的。