FIGURE 25. Rhadinacanthus longispinus head morphology. 1, 2, NMS G.1891.92.338 in The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland

FIGURE 25. Rhadinacanthus longispinus head morphology. 1, 2, NMS G.1891.92.338 from Gamrie, Banffshire; 1, head region; 2, magnified image of sensory line scales; 3, NMS G.1892.8.15 from Gamrie, Banffshire, head region. 4, 5, NHM OR.43276 from Tynet Burn, Moray: 4, complete specimen, head to left; 5, internal surface of right cheek plate, long anterior circumorbital bone, polygonal tesserae on tectal region. 6, NMS G.1892.8.10 from Gamrie, head region. Scale bars equal 1 cm for 1, 3, 4, 5, 6; 1 mm for 2. Abbreviations: ck.p=cheek plate; co.p=circumorbital plate; e=eye stain; oc.p=occlusal plate; so.sl=supraorbital sensory line. Arrows indicates anterior direction.