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Three species of sea spider (Arthropoda, Pycnogonida) have been described from the Middle Jurassic (Callovian) Konservat‐Lagerstätte of La Voulte‐sur‐Rhône: Palaeopycnogonides gracilis, Colossopantopodus boissinensis and Palaeoendeis elmii. These fossils were initially attributed to three extant families or superfamilies, justifying their use as calibration points in a recent tree‐dating analysis. However, their taxonomic affinities are still debated. Our knowledge of the morphology of these Jurassic sea spiders is limited by prior investigation with only light microscopy and radiographs, such that further morphological details such as cephalic appendages (chelifores, palps, ovigers) remain poorly documented. Here, we reinvestigate the La Voulte‐sur‐Rhône fossils using x‐ray microtomography and reflectance transformation imaging. A new specimen, tentatively attributed to P. gracilis, was found using x‐ray …