Genus Kallholnoceras Frye, 1987

Type species

Kallholnoceras cornutum Frye, 1987, Kallholn quarry, Kallholn, Dalarna, Sweden, Boda Formation, late Katian; by original designation.

Diagnosis

Exogastric, strongly curved cyrtocones with compressed conch cross section and gibbous mature body chamber; siphuncle close to conch margin, without endosiphuncular deposits with gradually enlarging; septal necks suborthochoanitic; siphuncle slightly expanded within chambers, without endosiphuncular deposits. (Compiled from Frye 1987.)