Cyptendoceras sp. A

Kröger, Björn & Pohle, Alexander, 2021, Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities, European Journal of Taxonomy 783 (1), pp. 1-102 : 44-45

Cyptendoceras sp. A

Fig. 9F–G

Material examined

Specimen FMNH-P30426 , from Profilstranda section, adjacent to Hinlopenstretet, Spitsbergen , bed PO 07 , 4 m above base of Olenidsletta Member, V1 a trilobite zone , Blackhillsian , Floian .

Description

The specimen is a fragment of a slightly crushed 30 mm long portion of a body chamber with the last septum preserved. The conch is smooth, straight and slender and has an elliptically depressed cross section with a height of 18 mm and a width of 22 mm (rW = 1.22). The preserved septum forms a suture that is slightly oblique across the flanks of the conch shifted toward the aperture at the antisiphuncular side of the conch; it forms shallow lateral saddles, is almost transverse dorsally, and forms a deep, broad u-shaped ventral lobe. The siphuncle is marginally positioned and elliptically depressed with a septal perforation 8 mm in height and 9 mm in width (rSD = 0.4). No details of the septal necks or the connecting ring are preserved.

Remarks

The specimen is assigned to Cyptendoceras because of the presence of the characteristic u-shaped ventral lobe. However, neither the septal spacing, nor the details of the septal necks and connecting ring are known, which precludes a species level determination of the specimen.

Figures

Fig. 9. Orthoconic cephalopods with large siphuncles from the Olenidsletta Member, Floian, Ordovician, Profilstranda section, Ny Friesland, Spitsbergen. A–B, D–E. Buttsoceras buldrebreenense sp. nov. A–B. Specimen FMNH-P30422, from bed PO 131. A. Adoral view of septum and septal perforation. B. Lateral view with prosiphuncular side toward right. C. Cyptendoceratid genus and species indet., FMNH-P30431, from bed PO 131. D. Specimen FMNH-P30423, from bed PO 131, lateral view. E. Specimen FMNH-P30421, holotype, lateral view, note faint transverse ornament partly preserved. F–G. Cyptendoceras sp. A, FMNH-P30426, from bed PO 07. F. Ventral view, prosiphuncular side. G. Adoral view of septum and septal perforation. H–I. Proterocameroceras valhallfonnense sp. nov., FMNH-P30277, from bed PO 131. H. Ventral view, prosiphuncular side. I. Adoral view of septum and septal perforation. Scale bar = 10 mm for all figures.