Fig. 23 in New insights into the origin and relationships of blastoid echinoderms

Fig. 23. Oral surface of the blastoid Codaster acutus McCoy, 1849, early Carboniferous, England, UK, showing interpretation of oral plating. Five ambulacra (A–E) are recumbent on the lancet plates (La) with the floor plates omitted for clarity. Five deltoid plates (d) form the mouth (M) frame and share the adoral parts of the hydrospire slits (H), the aboral parts of which are in the radial plates (R). An, anus. For plate homologies see Table 2.