Ostracodes of the Maple Mill Shale Formation (Upper Devonian) of southeastern Iowa, USA

The Upper Devonian Maple Mill Shale Formation in southeastern Iowa, U.S.A., has yielded a diverse and unusual ostracode fauna consisting of eighteen b enthic species and one (probably planktonic) entomozoacean species. Only tw o species have been previously described. Although the remaining species ar e considered new, because of poor preservation only three are named herein: Triceratina lethiersi n. sp., Graphiadactylloides kalonaensis n. sp. and E ntomozoe (Nehdentomis?) kindlei n. sp. At the species Level the fauna is un ique. The absence of Bairdiacea suggests a low oxygen (hypoxic) environment . Conodonts indicate that the ostracode-bearing layer correlates with the S caphignathus velifer Zone and fragments of cephalopods indicate the Platycl ymenia do III-IV Zone.