Stromer (1926) concluded that the faunas from the northern Sperrgebiet were of a steppic nature. The present study indicates that the area was more vegetated and more humid than envisaged by Stromer. The terrestrial gastropods are useful indicators of climate, and those from the Early Miocene deposits of the northern Sperrgebiet suggest that the region was close to a winter rainfall belt, but not necessarily within it, in contrast to its present day winter rainfall regime. The freshwater snails indicate that water bodies in the region were generally unstable, which concords with the overall aspect of aridity that the terrestrial faunas indicate. The presence of calcareous concretions of pedogenic origin at several sites, some forming continuous sheets (calcretes) as for example at Strauchpfütz, indicate that the region was not arid or hyper-arid, but more likely semi-arid to sub-humid. It certainly was not forested, but was most likely savanna, with denser stands of riparian vegetation along rivers and around water bodies such as ponds. It was only after the Early Miocene that hyper-arid conditions were established in the area, along with a predominantly winter rainfall climatic regime.