Leperditicopid ostracodes from Ordovician rocks of Kentucky and nearby states and characteristic features of the order Leperditicopida

Leperditicopid ostracodes from the Ordovician formations of Kentucky occur in micritic to fine-grained carbonate rocks believed to represent shallow-water facies. They are found at widely separated horizons in the Middle Ordovician High Bridge Group, the Middle and Upper Ordovician Lexington Limestone, and the Upper Ordovician Ashlock, Bull Fork, and Drakes Formations. In this sequence, the leperditicopes are represented by two genera of leperditiids, Eoleperditia Swartz, 1949 and Bivia Berdan, 1976, and six isochilinid genera, Isochilina Jones, 1858, Teichochilina Swartz, 1949, Ceratoleperditia Harris, 1960, Parabriartina n. gen., Kenodontochilina n. gen., and Saffordellina Bassler and Kellett, 1934; the type species of the hitherto poorly known genus Saffordellina, S. muralis (Ulrich and Bassler, 1923), is redescribed and refigured. In all, 18 taxa, of which 2 are in open nomenclature, are described and illustrated. In addition, the family Isochilinidae Swartz, 1949 is redefined to include genera without marginal brims and with straight ventral contact margins. The morphological characteristics of leperditicopid genera are discussed, and a table listing described genera and their diagnostic features is included.