A diverse group of molluscs from the Cambrian Series 2, Stages 3–4 Xinji Formation of the North China Block (NCB) is described, based on more than 4500 specimens from three well‐studied sections in Shaanxi and Henan provinces, along the southern and southwestern margin of the NCB. Twenty molluscan species are identified, including one bivalve, three stem group gastropods, and 16 additional helcionelloids. Among these, six helcionelloid species are reported from the NCB for the first time, and one new species, Parailsanella luonanensis sp. nov. is proposed. This diverse molluscan fauna shares a large number of species with contemporaneous faunas of South Australia (15), Antarctica (7), Laurentia (6), Siberia (3) and South China (1). Faunal similarities are even greater on a generic level. The striking similarities of the molluscan faunas of North China, South Australia and Antarctica strongly support the hypothesis that the NCB was situated close to Eastern Gondwana, most likely close to South Australia in the Cambrian Epoch 2. In addition, well‐preserved shell attachment muscle scars were observed in the helcionelloid Figurina figurina, with two pairs of symmetrical, continuous, band‐like muscle scars, which are obviously different from the musculature of both gastropods and monoplacophorans. Because of this unique musculature, these characteristic Cambrian cap‐like molluscs are assigned to the Helcionelloida rather than to the Gastropoda or Monoplacophora.

中文翻译：

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再次探讨华北寒武纪（系列2，第3-4期）新集组的软体动物区系

根据来自陕西和河南省南部，南部和北部三个地区的4500多份标本，描述了华北地块（NCB）寒武纪系列2 3-4期辛集组的一组不同的软体动物。 NCB的西南边缘。鉴定出二十种软体动物，包括一个双壳类，三个茎类腹足纲和另外16个半鳞翅目。在这些物种中，NCB首次报告了六种半绒毛species属物种，另外一个新物种是罗伊氏拟南芥。sp。十一月 被提议。这种多样的软体动物群落与南澳大利亚（15），南极洲（7），劳伦西亚（6），西伯利亚（3）和华南（1）的同期动物共有许多物种。在一般的层面上，动物的相似性甚至更大。华北，南澳大利亚和南极的软体动物区系惊人的相似性有力地证明了NCB靠近冈瓦纳东部，最有可能在寒武纪2时期靠近南澳大利亚。在helicionelloid Figurina雕像中观察到疤痕，具有两对对称的，连续的，带状的肌肉疤痕，这明显不同于腹足动物和单斜足动物的肌肉组织。由于这种独特的肌肉系统，这些典型的寒武纪帽状软体动物被分配给了Helicionelloida，而不是腹足纲或单斜足纲。