''Valcouroceras'' is the type genus for the

Valcouroceratidae The Valcouroceratidae is a family within the Oncocerida, nautiloid cephalopods from the middle and upper Ordovician, established by Rousseau Flower in 1945. Diagnosis Valcouroceratids are characterized by exogastric cyrtocones and brevicones tha ...

, a family in the nautiloid order

Oncocerida The Oncocerida comprise a diverse group of generally small nautiloid cephalopods known from the Middle Ordovician to the Mississippian (early Carboniferous; one possible member is known from the Early Permian), in which the connecting rings are t ...

named by Rousseau Flower, 1943, named for Valcour Island in

Lake Champlain , native_name_lang = , image = Champlainmap.svg , caption = Lake Champlain-River Richelieu watershed , image_bathymetry = , caption_bathymetry = , location = New York/Vermont in the United States; and Quebec in Canada , coords = , type = , ...

, between New York state and

Vermont Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...

, where it was first discovered. The shell of ''Valcouroceras'' is strongly curved, more so than in ''

Minganoceras ''Minganoceras'' is a genus in the oncocerid family, Valcouroceratidae, named by Foeste, 1938, from the Middle Ordovician of Quebec, found on Mingan Island. The shell of ''Minganoceras'' is a slender depressed exogastric cyrtocone, curved so tha ...

'', with the lower or ventral side on the outside curve. The body, or living, chamber is gibbous, broader near the middle than at the ends. The early growth stage is laterally compressed, higher than wide, then dorsally flattened, and finally depressed, wider than high. Septal necks of 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 ...

are straight, suborthochoanitic, nearly reaching he previous septa. Connecting rings start off thin but thicken in the later growth stages, which have well developed, internal radial, actinosiphonate deposits.

References

* Sweet, Walter C. (1964). Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology ''Part K Mollusca 3.'' Geological Society of America and University of Kansas Press.
''Valcouroceras''
brief in Paleobiology Database 6/16/12 Oncocerida Prehistoric nautiloid genera Fossils of Georgia (U.S. state) Taxa named by Rousseau H. Flower {{paleo-nautiloidea-stub