Haploceras is a late Upper Jurassic (Kimmeridgian and Tithonian) ammonoid cephalopod and type for the Haploceratidae, similar to Lissoceras but with a broader whorl section and small blunt lappets and a blunt rostrum; some species with feeble ventral folds on body chamber. Haploceras has been found worldwide, in North America, Africa, Europe and the mid east.