The Chesterian (Upper Mississippian) Imo Formation in north-central Arkansas contains an abundant, diverse, and well-preserved gastropod fauna, comprising 35 species referrable to 21 genera and subgenera. Bellerophontaceans and pleurotomariaceans show the greatest species diversity. New taxa proposed include: Euphemites chesterensis, E. whirligigi, Retispira yochelsoni, Patellilabia rhombadella, P. sulcata, Straparollus (Euomphalus) konobasis, S. (E.) variabilis, Trepospira (Angyomphalus) desultoria, Glabrocingulum (Glabrocingulum) parasolum, G. (G.) parvanodum, G. (G.) coronulum, Naticopsis (Marmolatella) macgordoni, N. (M.) imoensis, Globozyga mediocris, and Girtyspira microspirula.
Relicts of color patterns are present on four taxa. Repair of broken shells is common. Borings of acrothoracic barnacles and possibly that of a gastropod are present. Coprolites with gastropods attached may indicate a coprophagous habit, only grazing on the algae and bacteria growing on the coprolite, or may just be a circumstance of preservation.