FIGURE 20. Cheiracanthus grandispinus scale morphology. 1-3, 5-9 in A redescription of the three longest-known species of the acanthodian Cheiracanthus from the Middle Devonian of Scotland

FIGURE 20. Cheiracanthus grandispinus scale morphology. 1-3, 5-9, light microscope images; 4, 10-18, SEM images; midbody scales unless detailed otherwise. 1, NMS G.1891.92.317 from Lethen Bar. 2, NMS G.2019.9.8 from Jessie Port, Ross and Cromarty. 3, 4, USCP F00115b from Edderton. 5, NMS G.2019.9.9 from Achanarras, primordial scale revealed after abrasion/flaking of overlying crown growth zones. 6-9, NMS G.2019.9.10.1 from Cromarty: 6, mid-body scales; 7-9, pectoral fin web: spine and web; 8, distal scales; 9, scales near fin base. 10-12, NMS G.2019.9.11 from Marwick: 10, view of crown before removal of scale from matrix; 11, anterocrown view; 12, posterior view. 13, NMS G.2019.9.3.27.1 from Gamrie Den of Findon, laterocrown view. 14-18, NMS G.2019.9.13.8 from Cromarty, Eathie to Navity: 14, NMS G.2019.9.13.8.16, anterocrown view; 15, NMS G.2019.9.13.8.2 pair of scales in posterocrown view; 16, NMS G.2019.9.13.8.8, laterocrown view; 17, NMS G.2019.9.13.8.6, lateral view; 18, NMS G.2019.9.13.8.17, posterobasal view. Scale bars equal 0.5 mm in 1-9, 0.2 mm in 10-18. p, neck protuberance; ps, primordial scale. Arrows indicate anterior.