Choristoderan material from a microvertebrate horizon in the Czech Republic extends the history of the group into the early-middle Miocene. On cranial and vertebral morphology, the new Czech material most closely resembles Lazarussuchus inexpectatus from the Upper Oligocene of France. The morphological similarity supports attribution of the Czech material to the genus Lazarussuchus, but the combination of a smaller and more rounded upper temporal fenestra and the absence of accessory articular facets on the vertebrae distinguish the Czech form from the type species. The articulated skull of L. inexpectatus, re-examined for this study, and the disarticulated material of L. dvoraki sp. nov. complement each other, and permit a better understanding of skull morphology in this enigmatic genus. They demonstrate clearly that the lower temporal fenestra in Lazarussuchus was secondarily closed by apposition of the squamosal, jugal, quadratojugal, and postorbitofrontal.