Fig. 2 in Soft-tissue attachments in orthocerid and bactritid cephalopods from the Early and Middle Devonian of Germany and Morocco

Fig. 2. Schematic outlines of the variability of the dorsal furrow in Acanthomichelinoceras commutatum (Giebel, 1852), showing the base of a chamber mould, with annular elevation dotted. Note the differences of the starting point of the dorsal furrow, sometimes within the mural area, sometimes within the annular elevation. A. NHW 56.9.05/402. B. NHW 56.9.05/404. C. MB.C.5366.4. D. MB.C.5366.1. Not to scale.