ABSTRACT This paper presents the formal description of Impagidinium obscurum sp. nov. from the Thanetian strata of northwest Europe. The palaeogeographic distribution of this species covers a wide area, ranging from the North Sea to the Barents Sea. Palynologists working in the region have long referred to Impagidinium obscurum sp. nov. as Leptodinium? ‘obscurum' and used it as an important intraPaleocene marker species. The informal specific name was with reference to the incompletely defined tabulation of the cyst. However, although the tabulation is often obscured by the dense folding of the walls, the cyst tabulation formula has been partly deciphered in this work, based on the organisation of sutural crests in exceptionally well-preserved specimens, which allows confident attribution to the genus Impagidinium. This species is restricted to the ‘early’ Thanetian and is associated with diverse dinoflagellate cyst assemblages which include Alisocysta margarita and Areoligera gippingensis.

中文翻译：

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Impagidinium obscurum sp。11 月，北海和巴伦支海 Thanetian（古新世）的标记甲藻囊肿

摘要 本文介绍了 Impagidinium obscurum sp 的正式描述。十一月 来自欧洲西北部的 Thanetian 地层。该物种的古地理分布范围很广，从北海到巴伦支海。在该地区工作的孢粉学家长期以来一直提到 Impagidinium obscurum sp。十一月 作为 Leptodinium？'obscurum' 并将其用作重要的古新世内标记物种。非正式的具体名称是参考不完整定义的包囊列表。然而，尽管表格经常被壁的密集折叠所掩盖，但在这项工作中已经部分破译了囊肿表格公式，这是基于保存异常完好的标本中缝线嵴的组织，这使得有信心将其归因于 Impagidinium 属.