An early Chesterian (early Carboniferous; Late Mississippian) nautiloid fauna is described from the Ruddell Shale Member of the Moorefield Formation in Arkansas, Midcontinent North America. It consists of the three orthocerids, Euloxoceras buffalowallowense sp. nov., Mitorthoceras perfilosum Gordon and Moorefieldoceras yochelsoni gen. et sp. nov., and the two nautilids, Tylonautilus sp. and Peripetoceras milleri sp. nov. Reexamination of M. perfilosum, the type species of the genus, provides grounds for emendation of the generic concept emphasizing the supracentral position of the siphuncle. Moorefieldoceras is differentiated from comparable genera by its relatively rapid shell expansion, prominent annulations with a distinct ventral sinus, and relatively large siphuncle diameter with a central to subcentral position.