Fig. 25 in Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities

Fig. 25. Bactroceras boliviensis Aubrechtová, 2015, from bed PO 131, from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A. Specimen FMNH-P30430, lateral view of body chamber with dorsomyarian muscle impression at base ventral, prosiphuncular side toward the left. B. Specimen FMNH-P30231, view of ventral, prosiphuncular side. C. Specimen FMNH-P30248, lateral view of specimen with partly cyclic spacing of ornamentation; ventral, prosiphuncular side toward the right. D. Specimen FMNH-P30215, with fine transverse ornamentation; ventral, prosiphuncular side toward the right. Scale bar = 10 mm for all figures.