Abstract A new occurrence of the onychochilid mollusc Pelecyogyra is reported from the late Floian Landeyran Formation (Apatokephalus incisus Biozone) in the Montagne Noire, southern France, where it is associated with the two tergomyans Carcassonnella courtessolei and Thoralispira laevis, and a mollusc indet. with a low cap-shaped shell. The Montagne Noire specimens compare morphologically with Pelecyogyra fezouataensis from the late Tremadocian Fezouata Formation (Araneograptus murrayi Biozone) in Morocco and are tentatively referred to this species. Each occurrence of Pelecyogyra is from one or two localities only, but separated in time. They differ further in the deeper facies, association with Carcassonnella and Thoralispira, and non-gregarious occurrence in Montagne Noire compared to the shallower facies, lack of other molluscs and gregarious occurrence in the Fezouata Formation. In the Lower Ordovician, Pelecyogyra, Carcassonnella courtessolei, the rare C. vizcainoi and Thoralispira laevis are taxa that occur only in Montage Noire and the Anti-Atlas, while Lesueurilla prima also occurs in the Prague basin of the Czech Republic. Contrary to other faunal elements, like echinoderms and trilobites, these genera seem to have a wide environmental tolerance and are long ranging taxa. The main occurrence of the three key taxa Carcassonnella, Thoralispira and Lesueurilla in the Montagne Noire is in the lower part of the La Maurerie Formation (Taihungshania miqueli acme Zone), while the same taxa appear just slightly later in Morocco (?Cymatograptus protobalticus Biozone). Migration to the Anti-Atlas during the early Floian seems to have been possible during a period of general faunal exchange. Pelecyogyra may either have migrated from the Anti-Atlas to Montagne Noire during the same interval or possibly during the late Floian as indicated by shared faunal elements between these two regions at that time.

中文翻译：

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法国黑山早奥陶世的 Pelecyogyra（软体动物）

摘要 在法国南部黑山的晚 Floian Landeyran 组 (Apatokephalus incisus Biozone) 报道了一种新出现的甲壳类软体动物 Pelecyogyra，它与两种 tergomyans Carcassonnella courtessolei 和 Thoralispira laevis 以及一种软体动物有关。带有低帽形外壳。Montagne Noire 标本在形态上与来自摩洛哥晚 Tremadocian Fezouata 组（Araneograptus murrayi Biozone）的 Pelecyogyra fezouataensis 进行了比较，暂定为该物种。Pelecyogyra 的每次出现仅来自一两个地点，但在时间上是分开的。与较浅的相相比，它们在更深的相、与 Carcassonnella 和 Thoralispira 的关联以及在 Montagne Noire 中的非群居性存在进一步不同，Fezouata 组缺乏其他软体动物和群居动物。在下奥陶统，Pelecyogyra、Carcassonnella courtessolei、稀有的C. vizcainoi 和Thoralispira laevis 是仅出现在Montage Noire 和Anti-Atlas 的分类群，而Lesueurilla prima 也出现在捷克共和国的布拉格盆地。与棘皮动物和三叶虫等其他动物群元素相反，这些属似乎具有广泛的环境耐受性并且是分布广泛的分类群。黑山的三个关键分类群 Carcassonnella、Thoralispira 和 Lesueurilla 的主要产地位于 La Maurerie 组的下部（Taihungshania miqueli acme Zone），而相同的分类群出现在摩洛哥稍晚一些（?Cymatograptus protobalticus Biozone） . 在早期的弗洛亚人迁移到 Anti-Atlas 似乎是在一般的动物群交换时期可能的。Pelecyogyra 可能在同一时间段内从 Anti-Atlas 迁移到 Montagne Noire，或者可能在 Floian 晚期迁移，正如当时这两个地区之间共享的动物区系元素所表明的那样。