Nautilina

The Nautilina, proposed by Shimanskiy, is basically the Nautilaceae of Kummel, 1964, defined by Furnish and Glenister, but differs in omitting two families, the Paracenoceratidae and Pseudonautilidae which instead are placed in the Liroceratina.

The Nautilidae are involute or slightly evolute and generally smooth with straight to sinuous sutures.

The Hercoglossidae are smooth but with differentiated sutures, in some with deep lateral lobes and well-developed saddles.

The Aturiidae (Aturia) is similar to the Hercoglossidae except for being more discoidal and having a more complex suture and subdorsal siphuncle.

The Nautilidae gave rise to the Cymatoceratidae and Hercoglossidae during the Jurassic while the Herocoglossidae became ancestral to the Aturiidae near the beginning of the Cenozoic.