†Orthonybyoceras Shimizu and Obata 1935 (mollusk)
Cephalopoda - Orthocerida - Proteoceratidae
Parent taxon: Proteoceratidae according to B. Kröger et al. 2007
Sister taxa: Archigeisonoceras, Baykonuroceras, Cyrtactinoceras, Ephippiorthoceras, Euorthoceras, Gangshanoceras, Gorbyoceras, Isorthoceras, Liulinoceras, Mesnaquaceras, Metephippiorthoceras, Monomuchites, Paraproteoceras, Proteoceras, Pseudoliolinoceras, Stereospyroceras, Tofangoceras, Transorthoceras, Treptoceras, Ulmioceras
Subtaxa: Orthonybyoceras dyeri
Ecology: nektonic carnivore