''Chouteauoceras'' is an openly coiled, gyroconic,

nautiloid Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. Th ...

cephalopod from the

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

of North America belonging to the Nautilid family

Trigonoceratidae The Trigonoceratidae is a family of coiled nautiloid cephalopods that lived during the period from the Early Carboniferous ( Mississippian) to the Early Permian. Diagnosis Trigonoceratidae comprise members of the order Nautilida characterized ...

, and superfamily Trigonocerataceae. The whorl section of ''Chouteauoceras'' is ovate, higher than it is wide. The surface is covered with numerous longitudinal ridges and fine growth lines. The suture has broad rounded lateral lobes and dorsal and ventral saddles. The siphuncle is small, subcentral.

References

* Kummel, B, 1964; Nautiloidea- Nautilida;

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

Part K Nautiloidea; Geological Society of America and University of Kansas Press. {{Taxonbar, from=Q5105476 Prehistoric nautiloid genera