A Silurian ophiuroid with soft-tissue preservation

Most Palaeozoic brittle stars lack the fused arm ossicles (vertebrae) that facilitate the remarkable mode of walking that characterizes living forms. Here we describe a stem ophiuroid from the Herefordshire Lagerstatte (Silurian, Wenlock Series), which is exceptional in preserving the body cavity uncompacted and the long tube feet. We assign the specimen to the order Oegophiurida. The morphology of the arms and attitude of the specimen suggest that locomotion may have been achieved by arm propulsion combined with podial walking. This ophiuroid increases the diversity of echinoderm higher taxa with preserved soft parts represented in the Herefordshire Lagerstatte.