Living brittle stars (Echinodermata: Ophiuroidea) employ a very different locomotion strategy to that of any other metazoan: five or more arms coordinate powerful strides for rapid movement across the ocean floor. This mode of locomotion is reliant on the unique morphology and arrangement of multifaceted skeletal elements and associated muscles and other soft tissues. The skeleton of many Palaeozoic ophiuroids differs markedly from that in living forms, making it difficult to infer their mode of locomotion and, therefore, to resolve the evolutionary history of locomotion in the group. Here, we present three-dimensional digital renderings of specimens of six ophiuroid taxa from the Lower Devonian Hunsrück Slate: four displaying the arm structure typical of Palaeozoic taxa (Encrinaster roemeri, Euzonosoma tischbeinianum, Loriolaster mirabilis, Cheiropteraster giganteus) and two (Furcaster palaeozoicus, Ophiurina lymani) with morphologies more similar to those in living forms. The use of three-dimensional digital visualization allows the structure of the arms of specimens of these taxa to be visualized in situ in the round, to our knowledge for the first time. The lack of joint interfaces necessary for musculoskeletally-driven locomotion supports the interpretation that taxa with offset ambulacrals would not be able to conduct this form of locomotion, and probably used podial walking. This approach promises new insights into the phylogeny, functional morphology and ecological role of Palaeozoic brittle stars.

活脆的恒星（Echinodermata：Ophiuroidea）采用的运动策略与其他后生动物的运动策略截然不同：五个或更多的手臂协调强大的步伐，以便在海底快速移动。这种运动方式依赖于多面骨骼元素以及相关的肌肉和其他软组织的独特形态和排列。许多古生代蛇类动物的骨骼与生物形式的骨骼明显不同，因此难以推断其运动方式，因此难以解析该群体中运动的进化史。在这里，我们展示了来自下泥盆统洪斯吕克板岩的六个蛇形类群标本的三维数字化渲染：其中四个显示了古生代类群的典型臂结构（大肠钩虫（Encrinaster roemeri），大叶松柏（Euzonosoma tischbeinianum），罗勒斯特（Loriolaster mirabilis），切尔翅虫（Cheiropteraster giganteus）和两个（Furcaster palaeozoicus，Ophiurina lymani）的形态与生活形式更为相似。据我们所知，三维数字可视化技术的使用使这些分类单元的标本臂的结构可以在现场全面可视化。肌肉骨骼驱动的运动缺乏必要的关节接口，支持了这样的解释，即具有偏移的脚踝的分类单元将无法进行这种形式的运动，并且可能使用了足底行走。这种方法有望为古生代脆性星的系统发育，功能形态和生态作用提供新的见解。