''Elrodoceras'' is a genus of armenoceratids, (Cephalopoda, Actinocerida), that grew fairly large, characterized by a straight shell, slightly curved at the apex, a

siphuncle The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ...

narrower than that of ''

Armenoceras ''Armenoceras'' is a genus of actinocerid nautiloid cephalopods whose fossils ranged from the late Whiterockian Stage in the early Middle Ordovician, through the remainder of the period and on into the Upper Silurian. It is the type genus of th ...

'' but with segments still wider than long, and an arched endosiphuncular canal system. ''Elrodoceras'', which comes from the Middle Silurian of North America and Europe, is a late armenoceratid and, according to Curt Teichert, 1964, a member of one of the two branches of the

Armenoceratidae The Armenoceratidae are a family of early Paleozoic nautiloid cephalopods belonging to the order Actinocerida.Flower 1957.Studies of the Actinoceratida.; Memoir 2; New Mexico Bureau of Mines and Mineral Resources, Socorro, NM Teichert 1964. Act ...

that also includes ''Armenoceras'' and '' Monocyrtoceras''.

References

* Curt Teichert, 1964. Actinoceratoidea, Treatise on Invertebrate Paleontology, Part K. Geological Society of America and University of Kansas press. Prehistoric nautiloid genera Actinocerida Paleozoic life of Manitoba Paleozoic life of Nunavut Paleozoic life of Quebec {{paleo-nautiloidea-stub