''Reedsoceras'' is a genus of large discosorids (Nautiloidea) in the family

Westonoceratidae Westonoceratidae are exogastric, mostly compressed, Discosorida of moderate size from the Middle Ordovician to the Lower Silurian. The siphuncle is typically close to the convexly curved outer margin of the phragmocone – the chambered part o ...

from the middle and upper Ordovician of North America. ''Reedsoceras'' was named as a genus characterized by rapidly expanding exogastric cyrtocones with unconstricted apertures and straight sutures. The

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 ...

is close to the venter, which is the externally convex side of the shell, and is composed of very short, broadly rounded segments. Structure of the siphuncle wall is unknown. ''Reedsoceras'' seems to be derived from '' Simardoceras'' and to be more closely related to a group that also includes ''

Sinclairoceras ''Sinclairoceras'' is a nautiloid cephalopod in the discosorid family Westonoceratidae from the Middle Ordovician Simard Limestone of Quebec Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is th ...

'' than to other westonoceratids, especially those with long narrowing body chambers and bent back exogastric phragmocones like ''

Winnipegoceras ''Winnipegoceras'' is an extinct nautiloid genus from the Ordovician belonging to the Order Discosorida. Phylogeny ''Winnipegoceras'' is included in the discosorid family Westonoceratidae and is derived from '' Westonoceras''. Westonoceratidae ...

''.

References

* Flower, R.H.and Curt Teichert 1957. The Cephalopod Order Discosorida. University of Kansas Paleontological Contributions, Mollusca, Article 6. July 1957 * Teichert, C 1964. Nautiloidea -Discosorida. Treatise on Invertebrate Paleontology Part K. Geological Soc of America and Univ. Kansas Press. {{Taxonbar, from=Q7306749 Prehistoric nautiloid genera Ordovician molluscs Middle Ordovician first appearances Late Ordovician extinctions Discosorida