NEW OSTRACODA SPECIES FROM AN UPPER CRETACEOUS OYSTER REEF, NORTHERN GULF COASTAL-PLAIN, USA

This paper describes new species of Ostracoda from Late Cretaceous (late Santonian) oyster reefs of the Eutaw Formation of eastern Alabama, The reefs are composed almost exclusively of Ostrea cretacea Morton, with rarer occurrences of the oysters Exogyra upatoiensis Stephenson and Lopha ucheensis (Stephenson) and the bivalve Anemia preolmstedi Stephenson. Total thickness of the reefs is about 30 m, and the reefs are a major topographic feature across most of Macon and Russell Counties, Alabama, a distance of about 60 km. The reefs are interpreted to have been backbarrier sediments deposited under brackish conditions. Eight species of ostracodes are identified, including five new species described herein. The fauna is typically well preserved, and includes males, females, and juveniles. New species include Haplocytheridea? eutawensis, Antibythocypris dimorphicus, A. nephotrema, Brachycythere asymmetrica, and Eocytheropteron mutafoveata. Also discussed and illustrated are Cytherella tuberculifera Alexander, Haplocytheridea renfroensis renfroensis Crane, and Fissocarinocythere gapensis (Alexander).