Middle to Late Pleistocene human habitation in the western Nefud Desert, Saudi Arabia

The Nefud Desert is crucial for resolving debates concerning hominin demography and behaviour in the Saharo-Arabian belt. Situated at the interface between the Mediterranean Westerlies and African Monsoonal climate systems, the Nefud lies at the centre of the arid zone crossed by Homo sapiens dispersing into Eurasia and the edges of the southernmost known extent of the Neanderthal range. In 2013, the Palaeodeserts Project conducted an intensive survey of the western Nefud, to: (1) evaluate Pleistocene population dynamics in this important region of the Saharo-Arabian belt and (2) contribute towards understanding early modern human range expansions and interactions between different hominin species. Thirteen Lower and Middle Palaeolithic sites were discovered in association with palaeolake basins. One of the sites, T'is al Ghadah, may feature the earliest Middle Palaeolithic assemblage of Arabia. Preliminary analyses show that the Lower and Middle Palaeolithic sites discovered display diverse technological characteristics, indicating that the Nefud was important for population turnovers and exchanges throughout the Pleistocene. Periodic environmental amelioration appears to have attracted hominin incursions into the region, and subsequent ephemeral occupations structured around lakes and, to a lesser extent, raw material sources. However, differences between the Lower and Middle Palaeolithic sites are indicative of greater mobility during the later Pleistocene. A rarity of formal tools, but strong similarities in lithic production techniques, are also suggestive of demographic affinities across the Nefud during the Pleistocene, and perhaps beyond. These preliminary results support the view that the Arabian Peninsula was a critically important region of southwest Asia during the Late Pleistocene, in which demographic responses to climatic amelioration may have structured connectivity across the Saharo-Arabian belt, the Levant and as far as India