Full reference: E. O. Ulrich, A. F. Foerste, A. K. Miller and W. M. Furnish. 1944. Ozarkian and Canadian cephalopods, longicones and summary. Geological Society of America Special Paper 58:1-226
Parent taxon: Cephalopoda according to E. O. Ulrich et al. 1944
Sister taxa: Actinoceratoidea, Actinocerida, Actinodochmioceras, Akidocheilus, Ammonoidea, Aulacocerida, Ausseites, Avramidiscus, Bactritoidea, Belemnitida, Belopeltis, Belosaepia, Boletzkida, Botellusoceras, Burronoceras, Coleoidea, Conchorhynchus, Cyrtoceras, Dartoceras, Davidiceras, Deltoceratidae, Desmoceras, Discosorida, Dissimilites, Endoceratoidea, Erlangericheilus, Gonatocheilus, Hadrocheilus, Heyuncunoceras, Kailiceras, Kotetishvilia, Lamellaptychus, Leptocheilus, Lituitida, Mesoteuthoidea, Nautilida, Nautiloidea, Neptunoceratidae, Oncocerida, Orthoceratina, Orthoceratoidea, Orthodochmioceras, Palaeoteuthis, Patruliusiceras, Plectonocerida, Protactinocerida, Pseudorthocerida, Rhyncholite, Rhynchoteuthis, Robsonoceratidae, Sabbaiceras, Scaptorrhynchus, Sichunoceras, Songkanoceras, Spirulirostridae, Stemtonoceratidae, Tarphycerida, Tetrabranchiata, Tillicheilus, Toxancyloceras, Werthenoceras, Yanhecerida, Yannanoceras, Yichangoceras, Paratrematoceras, Balticoceras, Arkonoceras, Eotripteroceras, Hesperoceras, Sinoceras
Subtaxa: none
Type: Endocycloceras
Ecology: fast-moving nektonic carnivore