Cyptendoceras undefined-A

• Main Authors: Kröger, Björn, Pohle, Alexander
• Format: Other/Unknown Material
• Language: unknown
• Published: 2021
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Cephalopoda; Tetrabranchia; Cyptendoceratidae; Cyptendoceras; Cyptendoceras undefined-A; Hinlopenstretet; Ny Friesland; Spitsbergen
• Online Access: https://zenodo.org/record/5795747; https://doi.org/10.5281/zenodo.5795747

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. Published as part of Kröger, Björn & Pohle, Alexander, 2021, Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen - a pelagic fauna with Laurentian affinities, pp. 1-102 in European Journal of Taxonomy 783 (1) on pages 44-45, DOI:10.5852/ejt.2021.783.1601, http://zenodo.org/record/5793422