ABSTRACT

The Xenacanthiformes from Central and Eastern European deposits have been extensively studied, but the systematics of the species from the French Carboniferous–Permian Autun Basin (Saône-et-Loire) remains debated. Numerous xenacanthiform remains are still identified under the doubtful genus ‘Expleuracanthus’, and many of them consist of isolated dorsal spines which are difficult to identify. Numerous well-preserved specimens are still undescribed and the diversity of the xenacanthiform fauna from the Autun Basin is poorly understood. For example, specimens of the genus Triodus from the Muse oil-shale bed (OSB) of the Autun Basin have no specific attribution, whereas this genus is widely distributed across European Carboniferous–Permian basins. In this study, we describe new specimens of Triodus from the lowermost Permian of the Muse OSB. They allow the erection of a new species, Triodus aeduorum sp. nov., and discussion of the validity of several species from the same locality: ‘Expleuracanthus’ frossardi is considered as a nomen dubium and other Triodus specimens need for the time being to be left in open nomenclature as Triodus sp. These results highlight the endemism of the Triodus species in each European Carboniferous–Permian basin and raise the question of how they migrated from one to another.

摘要

来自中欧和东欧矿床的 Xenacanthiformes 已被广泛研究，但来自法国石炭纪 - 二叠纪 Autun 盆地（索恩-卢瓦尔河）的物种的系统学仍然存在争议。在可疑的“ Expleuracanthus ”属下，仍有许多异棘鱼残骸被鉴定，其中许多由难以鉴定的孤立背刺组成。许多保存完好的标本仍未得到描述，并且对来自 Autun 盆地的斑蝥类动物群的多样性知之甚少。例如，Triodus属的标本来自 Autun 盆地 Muse 油页岩层 (OSB) 没有具体归属，而该属广泛分布于欧洲石炭纪-二叠纪盆地。在这项研究中，我们描述了来自 Muse OSB 最底层二叠纪的Triodus新标本。它们允许建立新物种Triodus aeduorum sp。11 月，并讨论了来自同一地点的几个物种的有效性：' Expleuracanthus ' frossardi被认为是一个 nomen dubium，其他Triodus标本暂时需要作为Triodus sp.保留在开放命名中。这些结果突出了Triodus的特有性 每个欧洲石炭纪-二叠纪盆地的物种，并提出了它们如何从一个迁移到另一个的问题。