Fig. 9From: Siphonal tube structure of the Late Devonian orthocerid Dolorthoceras from the Polar Urals (NW Russia) preserving nacre and organic fibres as well as its persistence in cephalopod evolutionA schematic drawing of the siphonal tube structure in Dolorthoceras sp. (PIN-1894/100); River Malaya Usa, Polar Urals, NW Russia; Frasnian, Late Devonian. Scale bar is 30 µm. ch chamber, cl clutch, cr connecting ring, hse hyposeptal extension of the clutch along with connecting ring, icl inner part of clutch, s septum, siph siphuncle, ocl outer part of clutchBack to article page