Paleozoic scaphopods are among the most poorly known mollusks because of their featureless tubular shell morphology and fragmentary preservation. An apical orifice at the posterior end of a conch is a diagnostic character of Scaphopoda that distinguishes them from other groups of animals that produce similar calcareous tubes, but this structure is rarely preserved. A rich molluscan fauna from the Permian Akasaka Limestone in central Japan includes scaphopod shells, and past studies have reported four species, all of which were based on fragmentary specimens. This study recognizes six species in the Akasaka Limestone mainly on the basis of museum/institution collections, and a new genus (Minodentalium) and three species (Prodentalium onoi, M. hayasakai, and M. okumurai) are described, two known species (P. akasakensis and P. neornatum) are redescribed in more detail, and one species (Prodentalium sp.) is described under open nomenclature. The following eight known species are allocated to the new genus Minodentalium: Plagioglypta furcata Waterhouse, 1980; Pl. girtyi Knight, 1940; Pl. subannulata Easton, 1962; Dentalium ingens De Koninck, 1843; D. meekianum Geinitz, 1866; Pl. prosseri Morningstar, 1922; Dentalium priscum Münster in Goldfuss, 1842; and D. herculeum De Koninck, 1863. All the species, except for M. hayasakai, are gigantic, reaching 200 mm or more in length. The species richness is the greatest known from a single locality/formation worldwide.UUID: http://zoobank.org/35405b9d-3ba7-40bf-87c5-3f2b550b1a6d

中文翻译：

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来自日本中部二叠纪赤坂石灰岩的巨型腕足类动物（软体动物）

古生代的舟足类是最鲜为人知的软体动物之一，因为它们无特征的管状壳形态和碎片保存。海螺后端的一个顶端孔口是 Scaphopoda 的一个诊断特征，将它们与其他产生类似钙质管的动物群区分开来，但这种结构很少保存。来自日本中部二叠纪赤坂石灰岩的丰富的软体动物动物群包括舟足类，过去的研究报告了四个物种，所有这些物种都是基于碎片标本。本研究主要根据博物馆/机构的收藏品识别出赤坂石灰石中的 6 个物种，以及一个新属（小齿) 和三个物种 (原齿兽,米.早坂井， 和米.奥村井) 被描述，两个已知的物种 (磷.赤坂和磷.新生儿) 被更详细地重新描述，并且一个物种 (前齿sp.) 在开放命名法下进行描述。以下八个已知物种被分配到新属小齿：栉孔栉沃特豪斯，1980；PL.吉尔蒂奈特，1940；PL.亚环状伊斯顿，1962；牙菌德科宁克，1843；D. meekianum盖尼茨，1866；PL.普罗塞里晨星，1922；棱齿菌明斯特在 Goldfuss，1842 年；和D.大力神De Koninck，1863 年。所有物种，除了米.早坂井, 是巨大的, 达到 200 毫米或更长的长度。物种丰富度是全球单一地区/地层中最广为人知的。UUID：http://zoobank.org/35405b9d-3ba7-40bf-87c5-3f2b550b1a6d