FIGURE 17 in The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland

FIGURE 17. Drawings of transverse sections through Diplacanthus tenuistriatus pectoral and anterior dorsal fin spines. 1, 2, pectoral fin spine NMS G.2014.7.36 from Marwick, Orkney: 1, through pectoral spine and posterior end of pinnal plate; 2, slightly distal to the latter section; 3, 4, anterior dorsal fin spine NMS G.2014.7.35 from Marwick, Orkney; 3, midspine; 4, slightly proximal to latter section. Scale bars equal 1 mm. Abbreviations: cc=central pulp canal; e=enameloid; gl=growth line; ost=osteodentine; p.p=pinnal plate; uc=upper longitudinal canal. Arrows point to junction between pectoral fin spine and pinnal plate.