Faunal remains from a Middle Pleistocene lacustrine marl in Dakhleh Oasis, Egypt: palaeoenvironmental reconstructions

Vertebrates and invertebrates associated with lithic artifacts are reported from a later middle Pleistocene horizon in Dakhleh Oasis, probably dating to isotope stage 7. This represents the first middle Pleistocene fauna of this stage from a site in the Egyptian Western Desert and demonstrates the presence of extensive permanent lakes along the margin of the Libyan Escarpment. The fauna includes two freshwater snails (Limnaea stagnalis, Planorbis planorbis), a catfish (Clarias sp.), two reptiles (Varanus cf. griseus, ?Trionyx sp.), four water birds (Grus grus, Anas platyrhynchos, Anas sp. small, Arenaria interpres) and one land bird (Struthio camelus), and probably eleven mammals (Phacochoerus aethiopicus, Hippopotamus amphibius, Camelus ?thomasi, Pelorovis antiquus, ?Damaliscus, large antelope, Gazella sp. large, Gazella cf. dorcas, small antelope, Equus capensis, and possibly Hyaena hyaena). Most of the fossils derive from a near shore marl deposit in a freshwater lake that occupied a depression whose northern boundary coincides with the present southern margin of the oasis in its eastern end. Casts of the stems of reeds are also present. The animals represent a proximal freshwater tied fauna of obligatory aquatics and those who require freshwater during much of their activity, a distal savanna fauna of grazers, browsers or rooters who migrate to water on a diurnal cycle, and probable transitory avian migrants attracted to the palaeolake in passage. Human presence is attested by flakes and bifaces found in situ.