Editing Nautilida (section)

==Classification and phylogeny==

===Current classification===
The current classification of the Nautilida, in prevalent use,<ref>[https://www.paleodb.org  Paleobiology Database]</ref> is that of [[Bernhard Kummel]] (Kummel 1964) in the Treatise which divides the Nautilida into five superfamilies, the Aipocerataceae, Clydonautilaceae, Tainocerataceae, and Trigonocerataceae, mostly of the Paleozoic, and the later Nautilaceae. These include 22 families and some 165 or so genera (Teichert and Moore 1964)

===Other concepts===
Shimansky 1962 (in Kummel 1964) divided the Nautilida into five suborders, the mostly Paleozoic [[Centroceratina]], [[Liroceratina]], [[Rutocerina|Rutoceratina]], and [[Tainoceratina]], and the Mesozoic to recent [[Nautilina]]. These include superfamilies which are different from those of Kummel (1964) and of less extent. The Centroceratina are comparable to the Trigonocerataceae, the Liroceratina to the Clydonautilaceae, and the Nautilina to the Nautilaceae. The main difference is that the Rutoceratidae are included with the Aipocerataceae of Kummel (1964) in the Rutoceratina. The remaining Tainocerataceae are the Tainoceratina.

[[Rousseau Flower]] (1950) distinguished the Solenochilida, Rutoceratida, and Centroceratida, as separate orders, from the Nautilida, derived from the Barrandeocerida, which are now abandoned. Within the Nautilida, he placed 10 families, included in the Nautilaceae and the no longer considered ancestral Clydonautilaceae. Teichert's 1988 classification is an abridged version of Shimansky's and Flower's early schemes.

===Derivation and evolution===
Both Shimansky and Kummel derive the Nautilida from the [[Oncocerida]] with either the [[Acleistoceratidae]] or [[Brevicoceratidae]] (Teichert 1988) which share some similarities with the [[Rutoceratidae]] as the source. The Rutoceratidae are the ancestral family of the Tainocerataceae and of the Nautilida (Kummel 1964) and of Shimansky's and Teichert's Rutoceratina. 
 
The Tainocerataceae gave rise, probably through the ancestral Rutoceratidae, to the Trigonocerataceae and Clydonautiliaceae in the Devonian and to the Aipocerataceae early in the Carboniferous. The Trigonocerataceae, in turn, gave rise late in the Triassic through the Syringonautilidae to the Nautilaceae, which include the Nautilidae, with ''Nautilus''. (Kummel 1964)