Cycloplectoceras Ulrich, Foerste, Miller & Furnish, 1942

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 : 60

Genus Cycloplectoceras Ulrich, Foerste, Miller & Furnish, 1942

Type species

Cycloplectoceras miseri Ulrich, Foerste, Miller & Furnish, 1942 , from the Smithville Formation (Floian Stage), north of Smithville, Lawrence County, Arkansas, USA; by original designation.

Diagnosis

Small discoidal conch with nearly circular whorls in cross section; whorls are in contact and slightly impressed dorsally; extremely small umbilical perforation; surface ornamented with strong annulations and prominent growth lines, which form v-shaped ventral sinuses; sutures simple and nearly straight; siphuncle near the ventral wall of the conch (from Ulrich et al. 1942).