FIGURE 21 in The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland

FIGURE 21. Diplacanthus tenuistriatus specimens from Achanarras Quarry, Caithness, squamation and scale histology. 1, NMS G.1897.55.2 (Figure 13.1), impression of squamation anterior to base of posterior dorsal fin spine; 2, 3, NMS G.1897.55.1 (Figure 13.2), squamation above the anal fin, scale crown detail partly obscured by matrix; 4–9, NMS G.1897.55.1, serial sections from patch of midflank squamation: 4, 5, vertical transverse section of scale; 6, 7, vertical longitudinal section of scale; 8, vertical longitudinal section of scale; 9, horizontal section near the level of the base/neck rim of scale. Scale bars equal 1 cm in 1; 1 mm in 2–3; 0.1 mm in 4–9. Arrows indicate anterior direction, where relevant.