Hemichoanella Teichert & Glenister, 1954

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 : 47

Genus Hemichoanella Teichert & Glenister, 1954

Type species

Hemichoanella canningi Teichert & Glenister, 1954 , from Emanuel Formation, stage III (Bendigonian– Chewtonian, see Legg 1978; Floian), Emanuel Creek, Kimberley Division, Western Australia; by original designation.

Diagnosis

Orthoconic longicones with circular conch cross section; sutures with deep, narrow siphonal lobe; siphuncle marginal, nearly tubular with rSD ≈ 0.3; septal necks hemichoanitic, connecting ring thick (compiled from Teichert & Glenister 1954 and Furnish & Glenister 1964).

Remarks

The genus is provisionally placed within the Cyptendoceratidae because of the presence of a relatively wide siphuncle with relatively long septal necks and concave, relatively thick connecting rings (see additional remarks below in chapter Cladistic Analysis).