Diverse and abundant fossil taxa have been described in the lower Cambrian Shipai Formation in the Three Gorges area of Hubei Province, South China, but the taxonomy and diversity of the co-occurring brachiopod fauna are still far from clear. Here we describe the brachiopod fauna recovered from the Shipai Formation in the Three Gorges area of South China, including representatives of the subphylum Linguliformea: linguloids (Lingulellotreta ergalievi, Eoobolus malongensis, and Neobolidae gen. indet. sp. indet.), and an acrotretoid (Linnarssonia sapushanensis); and representatives from the subphylum Rhynchonelliformea: the calcareous-shelled Kutorginates (Kutorgina sinensis, Kutorgina sp., and Nisusia liantuoensis). This brachiopod assemblage and the first occurrence of Linnarssonia sapushanensis shell beds permit correlation of the Shipai Formation in the Three Gorges area of Hubei Province with the Stage 4 Wulongqing Formation in the Wuding area of eastern Yunnan. This correlation is further strengthened by the first appearance datum (FAD) of the rhynchonelliform brachiopod Nisusia in the upper silty mudstone of both the Shipai and Wulongqing formations. The new well-preserved material, derived from siliciclastic rocks, also gives critical new insights into the fine shell structure of L. sapushanensis. Microstructural studies on micromorphic acrotretoids (like Linnarssonia) have previously been restricted to fossils that were acid-etched from limestones. This is the first study to carry out detailed comparative ultrastructural studies on acrotretoid shells preserved in siliciclastic rocks. This work reveals a hollow tube and solid column microstructure in the acrotretoid shells from the Shipai Formation, which is likely to be equivalent of traditional column and central canal observed in shells dissolved from limestones.

中文翻译：

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华南三峡地区石牌组早寒武世（第4期）腕足动物

华南湖北省三峡地区下寒武统石牌组化石类群丰富多样，但其共生的腕足动物群的分类和多样性仍不清楚。在这里，我们描述了在华南三峡地区石牌组发现的腕足动物群，包括舌形亚门的代表：舌形亚门（linguloids）欧加利叶舌兰,马龙大黄蜂和 Neobolidae 属。索引。sp。indet.), 和一个下垂体 (萨普山林纳松); 和来自 Rhynchonelliformea 亚门的代表：钙质带壳的 Kutorginates (苦瓜,库托尔贾纳sp.，和连沱尼苏虫）。这个腕足类动物的组合和第一次出现萨普山林纳松贝层允许湖北省三峡地区石牌组与滇东武定地区四期五龙庆组对比。rhynchonelliform腕足动物的首次出现数据（FAD）进一步加强了这种相关性尼苏西亚石牌组和五龙庆组上层粉质泥岩中。这种来自硅质碎屑岩的保存完好的新材料也为我们的精细壳结构提供了重要的新见解。大号.萨普山. 微形尖头体的微观结构研究（如林纳松属) 以前仅限于从石灰石酸蚀的化石。这是第一项对保存在硅质碎屑岩中的尖体贝壳进行详细的比较超微结构研究的研究。这项工作揭示了石牌组下垂体壳中的空心管和实心柱微观结构，这可能与在从石灰岩溶解的贝壳中观察到的传统柱和中心管相当。