Namib Desert dunes of coastal southwestern Africa support a fauna including species adapted to a life committed exclusively to vegetationless dune crests and slipfaces. Fog and wind-blown plant detritus constitute a trophic base for this fauna, composed predominantly of tenebrionid beetles, arachnids and reptiles. Occurrence and characteristics of this fauna may be explained by the simultaneous presence of: (a) a cool, coastal climate in the dune areas; (b) extensive dune masses; (c) a rich, arid-adapted fauna over the western half of southern Africa including the Namib during the Quaternary.