Homaloceras
Introduction '''''Homaloceras''''' is an extinct nautiloid cephalopod from the Middle Devonian with a strongly curved shell, included in the nautilid family Centroceratidae. ''Homaloceras'' is characterized by a smooth, exogastrically curved and laterally compressed, cyrtoconic to gyroconic, shell with the ventral margin the outer rim. The venter is narrow and concave with a groove running down the middle; the dorsum on the inner rim, rounded; the sides broadly convex and convergent. The suture is only slightly sinuous, the siphuncle tubular and near the venter. ( 1964)''Homaloceras'', named by Whiteavus in 1891, and found in North America, in Canada, is the most primitive and one of the earliest genera assigned to the Centroceratidae. ( 1964)The Nautiloidea, in which ''Homaloceras'' is included, is a subclass of once diverse and numerous shelled cephalopods characterized by a retrochoantic siphuncle in which the septal necks point back toward the apex.
See also *List of nautiloids
References * , B. 1984; Nautiloidea -Nautilida; Treatise on Invertebrate Paleontology Part K, Geological Society of America and University of Kansas Press. * Sepkoski, J.J. Jr. 2002.A compendium of fossil marine animal genera. D.J. Jablonski & M.L. Foote (eds.). ''Bulletins of American Paleontology'' '''363''': 1–560.Sepkoski's Online Genus Database (CEPHALOPODA)