Parent taxon: Cephalopoda according to B. Kröger and B. Lefebvre 2012
Sister taxa: Actinoceratoidea, Akidocheilus, Anomalosaepiidae, Avramidiscus, Barrandeocerida, Belosaepia, Burronoceras, Coleoidea, Dartoceras, Davidiceras, Desmoceras, Didymoceras, Ectocochlia, Ellesmerocerida, Endoceratoidea, Endocycloceratidae, Erlangericheilus, Gonatocheilus, Hadrocheilus, Irianoceras, Lamellaptychus, Leptocheilus, Mesoteuthoidea, Multiceratoidea, Nautilia, Nautiloidea, Nautilus (Solenochilus), Ohioceratidae, Orthoceratoidea, Palaeoteuthis, Plectronoceratia, Plectronocerida, Rhyncholithes, Rhynchoteuthis, Robsonoceratidae, Scaptorrhynchus, Sichunoceras, Stemtonoceratidae, Tarphyceratia, Teratoceroides, Tetrabranchiata, Tillicheilus, Toxancyloceras, Werthenoceras, Yanhecerida
Subtaxa: Orthoceras acum Orthoceras austriacum Orthoceras baconicum Orthoceras billiemense Orthoceras blakei Orthoceras celticum Orthoceras increscens Orthoceras indoaustralicum Orthoceras lateseptatum Orthoceras lennaense Orthoceras mojsisovicsi Orthoceras multilabiatum Orthoceras nodosum Orthoceras pulchellum Orthoceras pulchristriatum Orthoceras rotundulum Orthoceras sandlingense Orthoceras shastense Orthoceras spitiense Orthoceras styriacum Orthoceras subellipticum Orthoceras subtiliseptatum Orthoceras triadicum Orthoceras variestriatum Pseudorthocerida
Ecology: fast-moving nektonic carnivore