Hypophylloceras is a Cretaceous ammonite with a finely ribbed, compressed, involute shell; some having periodic stronger ribs or folds. The suture is complex, with large, asymmetric and finely divided lobes; the 1st lateral being much larger than the external (=ventral) and 2nd lateral lobes. Saddle endings commonly not phylloid. Hypophylloceras includes Neophylloceras Shimizu 1934 (=Paraphylloceras Chimisu 1935 ), Hyporbulites Brestroffer 1947, Goretophylloceras Collingnon 1949 and Aphrotiticeras Mahmoud in Breister, 1952.