Mississippian polyplacophoran (Mollusca) from Utah

Reports of Mississippian polyplacophorans from North America are rare. To date only three species, Gryphochiton parvus (Stevens, 1858) and G. elevatus (Kues, 1978), from the Salem Limestone in Indiana, and Elachychiton juxtaterminus Hoare and Mapes, 1985, from the Imo Formation in Arkansas, have been recognized (Smith and Hoare, 1987). Lobarochiton anomalus (Rowley, 1908), from the Louisiana Limestone in Missouri, is now believed to be Devonian in age. European reports of Lower Carboniferous polyplacophorans are much more common, at least 29 species (Hoare and Smith, 1987). The location of any specimen in the Mississippian of North America becomes significant in filling out the geologic history of this taxonomic group.