ABSTRACT The distinctive, tall and slender cyrtoconic shell of the gastropod Pollicina cyathina Koken, 1897, originally established on a poorly preserved internal mould from the Middle Ordovician of the Dalarna region of central Sweden, is redescribed on the basis of additional material from several localities in the vicinity of Rättvik. Repaired injuries preserved in the fine comarginal growth lines of the archinacelloidean gastropod indicate failed durophagous predatory attacks. Unusual apical structures on an internal mould from Sjurberg probably result from closure of the earliest growth stages later in ontogeny.

中文翻译：

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达拉拇指：来自瑞典达拉纳奥陶纪的 Pollicina cyathina (Gastropoda) 的壳形态和捕食失败

摘要 腹足动物 Pollicina cyathina Koken 独特、高大而纤细的圆锥形外壳，1897 年，最初建立在瑞典中部达拉纳地区中奥陶世保存不良的内部模具上，根据来自几个地方的额外材料重新描述拉特维克附近。Archinacelloidean 腹足类动物的精细边缘生长线中保留的修复损伤表明硬食性掠食性攻击失败。来自 Sjurberg 的内部霉菌上不寻常的顶端结构可能是由于个体发育后期最早生长阶段的关闭所致。