Fig. 3

Paratype of Helenodora inopinata (FMNH PE29050). a Part and (c) counterpart from the Francis Creek Shale, Westphalian D, Middle Pennsylvanian. Specimen preserved in dorso-ventral aspect and photographed wet under cross-polarised light. b Camera lucida drawing of part shows body outline and outline of limbs, as well as patches of annulated cuticle, shaded in grey. Location of disputed claws indicated, further illustrated in fig. 6. Scale bar = 10 mm. High resolution versions of each photograph provided in additional materials (Additional file 3)