Orthoceratinae M'Coy, 1884

Kröger, Björn, 2004, Revision of Middle Ordovician orthoceratacean nautiloids from Baltoscandia, Acta Palaeontologica Polonica 49 (1), pp. 57-74 : 59

Subfamily Orthoceratinae M'Coy, 1884 [nom. transl. Sweet 1964 ex Orthoceratidae ]

Diagnosis.— Orthoceratidae with smooth shell, with fine longitudinal or transverse striation or with reticulate shell ornamentation. The shell expanding at a very small angle. 2–5 furrows in the living chamber.

Remarks.—In 1956 Balashov established the genus Bifeovoceras . The genus was accepted as a valid taxon of the Orthoceratinae by Balashov and Zhuravleva (1962) and Sweet (1964). Dzik (1984), however, regarded it as a junior, subjective synonym of Orthoceras Brugière, 1789 . The proposal of Dzik (1984) is followed here (see discussion of Orthoceras bifeovatum Noetling, 1884 ).

Genera included.— Orthoceras Brugière, 1789 , Ctenoceras Noetling, 1884