SEM (A), µCT surface rendering (B, C) and 2D section (D–O) images of the isolated vertebral ossicles of Asteronyx loveni (NSMT E-5638). A, B basal view, arrow heads indicate oral groove C oral view D–O transverse vertical sections from basal (D) to distal (O) arm, basal view. Arrow heads indicate radial water canals (D–I) and radial nerve canals (K–O). Arrows indicate the orientations (ab, aboral; ba, basal; dis, distal; or, oral). Abbreviations: RNC, pore of radial nerve canal; RWC, pore of radial water canal.