†Didymoceras cheyenense Meek and Hayden 1856 (ammonite)
Cephalopoda - Ammonoidea - Nostoceratidae
Alternative combinations: Ancyloceras cheyenensis, Helicoceras cheyenense, Turrilites cheyenensis
Belongs to Didymoceras according to W. J. Kennedy et al. 2000
Sister taxa: Didymoceras angulatum, Didymoceras binodosum, Didymoceras californicum, Didymoceras cheyennense, Didymoceras cochleatus, Didymoceras hornbyense, Didymoceras navarroensis, Didymoceras nebrascense, Didymoceras newtoni, Didymoceras nicolletii, Didymoceras platycostatum, Didymoceras stevensoni, Didymoceras subtuberculatum, Didymoceras tenuicostatus, Didymoceras tortus, Didymoceras tricostatus, Didymoceras umbilicatus, Didymoceras uncus, Didymoceras vespertinus
Ecology: fast-moving nektonic carnivore