Taphonomic and zooarchaeological investigations at the middle Pleistocene site of Ti's al Ghadah, western Nefud Desert, Saudi Arabia

In recent years, the Arabian Peninsula has emerged as a key region for elucidating hominin and faunal evolution and dispersals between Africa and Eurasia. Central to this research is the middle Pleistocene site of Ti's al Ghadah (TAG) which has yielded a diverse and abundant fossil faunal assemblage and the earliest chronometrically dated evidence for hominins in this part of the world. Here, we present the first detailed taphonomic study of the large Unit 5 fossil assemblage from the site. We aim to assess which actor/s were responsible for the accumulation of the assemblage and evaluate evidence that might be consistent with the accumulation of fauna by hominins. We also describe, for the first time, fossils and lithic artefacts from stratigraphic horizons not previously considered, providing taphonomic insights into their accumulation. The taphonomic work shows that the Unit 5 faunal assemblage was accumulated by ambush predators, likely large felids and hominins, in a lake side environment, and that carcasses were subsequently scavenged by more durophagus carnivores such as hyenas and canids. Less can be reliably said regarding the newly described fossil assemblages given their poor preservation and significant wind abrasion, but large carnivores again appear to have played a role, and hominins probably played a role in the accumulation of at least one of these. This study provides the first detail insights into the interplay between hominins, carnivores, and herbivores in Arabia, and suggests that watering holes have been a focus on the Arabian landscape for resources since the middle Pleistocene

Prehistory and palaeoenvironments of the western Nefud Desert, Saudi Arabia

Mid-latitude dune fields offer significant records of human occupations in southwest Asia, reflecting human responses to past climate changes. Currently arid, but episodically wetter in the past, the Nefud desert of northern Saudi Arabia provides numerous examples of human-environment interactions and population movements in the desert belt. Here we describe results from interdisciplinary surveys in the western Nefud that targeted palaeolake deposits identified using satellite imagery. Surveys indicate the presence of thousands of discrete palaeolakes and palaeowetlands, providing valuable palaeoenvironmental records, and numerous archaeological and palaeontological assemblages. Geomorphological investigations suggest that many further deposits remain buried. Forty-six prehistoric archaeological sites have been identified in association with freshwater deposits, spanning the Lower Palaeolithic to the pre-Islamic Holocene. Lower Palaeolithic sites appear concentrated close to raw material sources near the Nefud fringe, despite the presence of freshwater and fauna deeper in the dune field. Middle Palaeolithic occupations extend more broadly, and by the early Holocene humans were at least periodically occupying areas deep in the desert. We present the first records of Neolithic sites in this dune field, including substantial hearth complexes distributed relatively deep within the dunes, potentially indicating increased mobility during this period. Later Holocene sites with stone structures are present around the dune fringes. Our results indicate that, during wet periods of the Pleistocene and Holocene, water in the western Nefud may have been more readily available than elsewhere in northern Arabia due to the high density of depressions where wetlands can form. The high frequency of lakes or marshes appears to have facilitated human occupations and dispersal through the regionFieldwork in Saudi Arabia was funded by the Saudi Commission for Tourism and National Heritage and the European Research Council (no. 295719, to MDP). JL is supported by ARC Laureate Project FL120100156 to S O'Connor (ANU)

A taxonomic and taphonomic study of Pleistocene fossil deposits from the western Nefud Desert, Saudi Arabia

Over the past decade, a growing interest has developed on the archaeology, palaeontology, and palaeoenvironments of the Arabian Peninsula. It is now clear that hominins repeatedly dispersed into Arabia, notably during pluvial interglacial periods when much of the peninsula was characterised by a semiarid grassland environment. During the intervening glacial phases, however, grasslands were replaced with arid and hyperarid deserts. These millennial-scale climatic fluctuations have subjected bones and fossils to a dramatic suite of environmental conditions, affecting their fossilisation and preservation. Yet, as relatively few palaeontological assemblages have been reported from the Pleistocene of Arabia, our understanding of the preservational pathways that skeletal elements can take in these types of environments is lacking. Here, we report the first widespread taxonomic and taphonomic assessment of Arabian fossil deposits. Novel fossil fauna are described and overall the fauna are consistent with a well-watered semiarid grassland environment. Likewise, the taphonomic results suggest that bones were deposited under more humid conditions than present in the region today. However, fossils often exhibit significant attrition, obscuring and fragmenting most finds. These are likely tied to wind abrasion, insolation, and salt weathering following fossilisation and exhumation, processes particularly prevalent in desert environments