Muscle scars of late Paleozoic freshwater ostracodes from West Virginia

Different adductor muscle attachment scar patterns of the three ostracode genera Darwinula Brady and Robertson, 1885, Gutschickia Scott, 1944, and Whipplella Holland, 1934, from Pennsylvanian and Permian rocks of 'West Virginia are illustrated for the first time. Gutschickia and Whipplella have been considered as junior synonyms of Carbonita Strand, 1928, and the oldest darwinulid scar pattern previously known was from the Upper Triassic of Germany. The different patterns document the presence of Darwinula in the Pennsylvanian of the United States and indicate that Whipplella and Gutschickia are valid genera. The use of ostracodes in discriminating between Carboniferous and Permian continental sedimentary rocks should be based on restudy of the species in these genera.