Chazyoceras
 Chazyoceras is a moderately large endocerid included in the Endoceratidae with a Nanno type apex and a ventral siphuncle with a holochoanitic wall characteristic of the family. The siphuncle swelling at the apex is subtriangular in longitudinal profile. The endocones are of medium length.Chazyoceras was named by Rousseau Flower in 1958. The genotype is Chazyoceras valcourense which came from the Middle Chazyan (Lower Middle Ordovician) of Valcour Island on Lake Champlain.