Türtscher Julia, Jambura Patrick L, Spindler Frederik, Kriwet Jürgen
Department of Palaeontology, Faculty of Earth Sciences, Geography and Astronomy, Evolutionary Research Group, University of Vienna, Vienna, Austria.
Vienna Doctoral School of Ecology and Evolution (VDSEE), University of Vienna, Vienna, Austria.
PLoS One. 2025 Jan 23;20(1):e0310174. doi: 10.1371/journal.pone.0310174. eCollection 2025.
The Late Jurassic fossil deposits of southern Germany, collectively known as the 'Solnhofen Archipelago', are one of the world's most important sources of Mesozoic vertebrates. Complete skeletons of cartilaginous fishes (Chondrichthyes), whose skeletal remains are rare in the fossil record and therefore all the more valuable, are represented, among others, by exceptionally well-preserved rays (superorder Batomorphii). Despite their potential for research in several areas, including taxonomy, morphology, ecology, and phylogeny, the number of studies on these chondrichthyans is still very limited. Here, we identify a previously unknown ray, †Apolithabatis seioma gen. et sp. nov., which represents the first record of a ray species from the upper Kimmeridgian of Painten, Germany, and thus the oldest Late Jurassic ray taxon from Germany based on skeletal remains. This new batomorph is characterised by a unique body shape and a combination of skeletal features that distinguish it readily from all other known Late Jurassic rays. Two different morphometric approaches confirm differences in body shape and proportions to all known Late Jurassic conspecifics. We thus extend the recent taxonomic revision of these rays and include all described holomorphic specimens in a phylogenetic framework using strict cladistic principles. The phylogenetic analysis reveals all Late Jurassic batomorphs to represent a monophyletic group, for which we introduce the new order Apolithabatiformes, which is sister to all other batomorphs representing a stem group. While the phylogenetic relationships within Apolithabatiformes ord. nov. remain largely unresolved, †Apolithabatis gen. nov. is placed as the sister to †Aellopobatis. This highlights that, despite considerable progress in our understanding of the diversity and phylogeny of early rays, difficulties remain in establishing robust relationships within batomorphs. We therefore emphasise the importance of comprehensive studies of completely preserved fossil cartilaginous fishes to obtain a better understanding of chondrichthyan evolution and their systematics in deep time.
德国南部的晚侏罗世化石矿床，统称为“索伦霍芬群岛”，是世界上中生代脊椎动物的最重要来源之一。软骨鱼类（软骨鱼纲）的完整骨骼在化石记录中很少见，因此更具价值，其中保存异常完好的鳐鱼（鳐总目）就有完整骨骼。尽管它们在分类学、形态学、生态学和系统发育学等多个领域具有研究潜力，但对这些软骨鱼类的研究数量仍然非常有限。在这里，我们鉴定出一种此前未知的鳐鱼，†阿波利萨鳐属新属新种（Apolithabatis seioma gen. et sp. nov.），它是德国派滕金默里迪阶上部鳐鱼物种的首次记录，因此是基于骨骼遗骸的德国最古老的晚侏罗世鳐鱼分类单元。这种新的鳐总目鱼类具有独特的体型和一系列骨骼特征组合，使其很容易与所有其他已知的晚侏罗世鳐鱼区分开来。两种不同的形态测量方法证实了其与所有已知晚侏罗世同类在体型和比例上的差异。因此，我们扩展了对这些鳐鱼的最新分类修订，并使用严格的分支系统学原理将所有已描述的全模标本纳入系统发育框架。系统发育分析表明，所有晚侏罗世的鳐总目鱼类代表一个单系群，我们为此引入了新目阿波利萨鳐目（Apolithabatiformes），它是所有其他代表干群的鳐总目鱼类的姐妹群。虽然阿波利萨鳐目新目内部的系统发育关系在很大程度上仍未解决，但†阿波利萨鳐属新属被置于†埃洛波鳐属（Aellopobatis）的姐妹位置。这突出表明，尽管我们在理解早期鳐鱼的多样性和系统发育方面取得了相当大的进展，但在确立鳐总目鱼类内部的稳健关系方面仍然存在困难。因此，我们强调对完全保存的化石软骨鱼类进行全面研究的重要性，以便更好地了解软骨鱼类在漫长时间里的进化及其分类学。
