Dinosaur body fossil material is rare in Scotland, previously known almost exclusively from the Great Estuarine Group on the Isle of Skye. We report the first unequivocal dinosaur fossil from the Isle of Eigg, belonging to a Bathonian (Middle Jurassic) taxon of uncertain affinity. The limb bone NMS G.2020.10.1 is incomplete, but through a combination of anatomical comparison and osteohistology, we determine it most likely represents a stegosaur fibula. The overall proportions and cross-sectional geometry are similar to the fibulae of thyreophorans. Examination of the bone microstructure reveals a high degree of remodelling and randomly distributed longitudinal canals in the remaining primary cortical bone. This contrasts with the histological signal expected of theropod or sauropod limb bones, but is consistent with previous studies of thyreophorans, specifically stegosaurs. Previous dinosaur material from Skye and broadly contemporaneous sites in England belongs to this group, including Loricatosaurus and Sarcolestes and a number of indeterminate stegosaur specimens. Theropods such as Megalosaurus and sauropods such as Cetiosaurus are also known from these localities. Although we find strong evidence for a stegosaur affinity, diagnostic features are not observed on NMS G.2020.10.1, preventing us from referring it to any known genera. The presence of this large-bodied stegosaur on Eigg adds a significant new datapoint for dinosaur distribution in the Middle Jurassic of Scotland.

中文翻译：

---

来自苏格兰艾格岛（Valtos 砂岩组，中侏罗纪）的第一只恐龙

恐龙身体化石材料在苏格兰很罕见，以前几乎完全来自斯凯岛上的大河口群。我们报告了来自艾格岛的第一个明确的恐龙化石，属于不确定亲和力的巴通期（中侏罗纪）分类群。肢骨 NMS G.2020.10.1 不完整，但通过解剖比较和骨组织学的结合，我们确定它很可能代表剑龙腓骨。整体比例和横截面几何形状类似于 thyreophorans 的腓骨。对骨微观结构的检查显示，剩余的初级皮质骨中存在高度重塑和随机分布的纵向管。这与预期的兽脚类动物或蜥脚类动物肢体骨骼的组织学信号形成对比，但与之前对 thyreophorans，特别是剑龙的研究一致。以前来自斯凯岛的恐龙材料和英格兰广泛同时代的遗址属于这一组，包括鹦鹉龙和肉瘤和一些不确定的剑龙标本。兽脚类动物如巨龙和蜥脚类动物，例如鲸鱼龙从这些地方也知道。尽管我们发现了剑龙亲缘关系的有力证据，但在 NMS G.2020.10.1 上没有观察到诊断特征，这使我们无法将其引用到任何已知属。Eigg 上这种大型剑龙的存在为苏格兰中侏罗纪恐龙分布增加了一个重要的新数据点。