The Late Triassic fauna of the Lossiemouth Sandstone Formation (LSF) from the Elgin area, Scotland, has been pivotal in expanding our understanding of Triassic terrestrial tetrapods. Frustratingly, due to their odd preservation, interpretations of the Elgin Triassic specimens have relied on destructive moulding techniques, which only provide incomplete, and potentially distorted, information. Here, we show that micro-computed tomography (μCT) could revitalise the study of this important assemblage. We describe a long-neglected specimen that was originally identified as a pseudosuchian archosaur, Ornithosuchus woodwardi. μCT scans revealed dozens of bones belonging to at least two taxa: a small-bodied pseudosuchian and a specimen of the procolophonid Leptopleuron lacertinum. The pseudosuchian skeleton possesses a combination of characters that are unique to the clade Erpetosuchidae. As a basis for investigating the phylogenetic relationships of this new specimen, we reviewed the anatomy, taxonomy and systematics of other erpetosuchid specimens from the LSF (all previously referred to Erpetosuchus). Unfortunately, due to the differing representation of the skeleton in the available Erpetosuchus specimens, we cannot determine whether the erpetosuchid specimen we describe here belongs to Erpetosuchus granti (to which we show it is closely related) or if it represents a distinct new taxon. Nevertheless, our results shed light on rarely preserved details of erpetosuchid anatomy. Finally, the unanticipated new information extracted from both previously studied and neglected specimens suggests that fossil remains may be much more widely distributed in the Elgin quarries than previously recognised, and that the richness of the LSF might have been underestimated.

中文翻译：

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基于 μCT 扫描技术的三叠纪晚期“埃尔金爬行动物”动物群中的 Erpetosuchus（Archosauria：Pseudosuchia）和新的erpetosuchid 材料的修订

来自苏格兰埃尔金地区的洛西茅斯砂岩组 (LSF) 的晚三叠世动物群对于扩大我们对三叠纪陆地四足动物的了解至关重要。令人沮丧的是，由于它们奇怪的保存，对埃尔金三叠纪标本的解释依赖于破坏性的成型技术，这些技术只能提供不完整且可能扭曲的信息。在这里，我们展示了微型计算机断层扫描 (μCT) 可以重振对这一重要组合的研究。我们描述了一个长期被忽视的标本，它最初被确定为伪鳄类主龙，伍德沃迪鸟鳄. μCT 扫描显示数十块骨头属于至少两个分类群：一个小体型假鳄类和一个原鳞类标本细叶虫. 假鳄类骨骼拥有进化枝 Erpetosuchidae 独有的特征组合。作为研究这个新标本的系统发育关系的基础，我们回顾了来自 LSF 的其他 erpetosuchid 标本的解剖学、分类学和系统学（之前都提到过鲱鱼）。不幸的是，由于可用的骨架的不同表示鲱鱼标本，我们无法确定我们这里描述的erpetosuchid标本是否属于鲶鱼（我们表明它与之密切相关）或者它是否代表一个独特的新分类单元。尽管如此，我们的结果揭示了很少保存的erpetosuchid解剖细节。最后，从先前研究和被忽视的标本中提取的出乎意料的新信息表明，化石遗骸在埃尔金采石场的分布可能比以前认识到的要广泛得多，并且 LSF 的丰富性可能被低估了。