The temnospondyl amphibian Zatrachys serratus Cope, 1878, is reported for the first time from the eastern United States on the basis of a partial skull table and isolated cranial elements from the Upper Pennsylvanian (Virgilian) of the Benwood Limestone Member of the Pittsburgh Formation, Monongahela Group, and the Lower Permian (Wolfcampian) Greene Formation, Dunkard Group, West Virginia. The partial skull table differs in several features from those of the well-preserved series of skulls of Z. serratus from the Lower Permian of New Mexico, particularly in the proportions of the postfrontal and postorbital. However, in view of the paucity of West Virginia material and the wide range of reported intraspecific variation, some possibly attributable to sexual dimorphism, and developmental changes in the cranial morphology of the New Mexico specimens, the conservative course is taken by referring the former to Z. serratus.

Known otherwise only from the Lower Permian (Wolfcampian and Leonardian) of Texas, New Mexico, and Oklahoma, the new occurrence of Z. serratus represents significant extensions of its stratigraphic and geographic ranges.