THE TAXONOMY AND BIOSTRATIGRAPHY OF CENOMANIAN AND TURONIAN (LATE CRETACEOUS) OSTRACODA FROM THE WESTERN INTERIOR BASIN, SOUTHWEST UTAH, USA

Cenomanian-Turonian ostracodes are reported from the western Colorado Plateau in the United States. Fifteen genera and twenty species of ostracode are illustrated, five of which are new. Nonmarine taxa include species of Hourcquia, Darwinula, Rosacythere, and Virgatocypris. Brackish taxa include Fossocytheridea posterovata, F. mosbyense, F. kirklandi. New brackish/marine marine taxa include Cytheromorpha sp., Looneyella sp., Asciocythere spp., and Cytheropteron. Cosmopolitain marine taxa include Cytherella spp., Dolocytheridea crassa, Cytheropteron eximium, Eucytherura sp., and Looneyella. Three Ostracode Interval Zones are proposed that broadly correspond to the existing late Cenomanian through to middle Turonian molluscan biozones as follows: 1) Ostracode Zone I equivalent to the Metoicoceras mosbyense Ammonite Zone; 2) Ostracode Zone II equivalent to the Sciponoceras gracile-Neocardioceras juddii Ammonite Zones; and 3) Ostracode Zone III corresponding to the Lower-to Middle Turonian Watinoceras devonense-Prionocyclus hyatti Ammonite Zones.