Inland human settlement in southern Arabia 55,000 years ago. New evidence from the Wadi Surdud Middle Paleolithic site complex, western Yemen

Abstract

The recovery at Shi'bat Dihya 1 (SD1) of a dense Middle Paleolithic human occupation dated to 55 ka BP sheds new light on the role of the Arabian Peninsula at the time of the alleged expansion of modern humans out of Africa. SD1 is part of a complex of Middle Paleolithic sites cut by the Wadi Surdud and interstratified within an alluvial sedimentary basin in the foothills that connect the Yemeni highlands with the Tihama coastal plain. A number of environmental proxies indicate arid conditions throughout a sequence that extends between 63 and 42 ka BP. The lithic industry is geared toward the production of a variety of end products: blades, pointed blades, pointed flakes and Levallois-like flakes with long unmodified cutting edges, made from locally available rhyolite. The occasional exploitation of other local raw materials, that fulfill distinct complementary needs, highlights the multi-functional nature of the occupation. The slightly younger Shi'bat Dihya 2 (SD2) site is characterized by a less elaborate production of flakes, together with some elements (blades and pointed flakes) similar to those found at SD1, and may indicate a cultural continuity between the two sites. The technological behaviors of the SD1 toolmakers present similarities with those documented from a number of nearly contemporaneous assemblages from southern Arabia, the Levant, the Horn of Africa and North Africa. However, they do not directly conform to any of the techno-complexes typical of the late Middle Paleolithic or late Middle Stone Age from these regions. This period would have witnessed the development of local Middle Paleolithic traditions in the Arabian Peninsula, which suggests more complex settlement dynamics and possible population interactions than commonly inferred by the current models of modern human expansion out of Africa.

Variability in the Middle Stone Age of Eastern Africa

“…This hypothesis has clear parallels with Dennell and Roebroek's (2005) concept of "Savannahstan," with initial hominins dispersing into Asia remaining within African-like environments. Later (∼55 ka) sites from the Arabian peninsula during arid intervals lack Nubian Type 1 cores and suggest instead the development of regionally distinct variants in Arabia and Africa with environmental change (Delagnes et al 2012). …”

Remote sensing and GIS techniques for reconstructing Arabian palaeohydrology and identifying archaeological sites

“…Palaeohydrology is key to understanding the dispersal of hominins into the Arabian Peninsula during the Quaternary, and for exploring hypotheses relating to the expansion and contraction of Palaeolithic populations both within Arabia and between regional refugia (Petraglia and Alsharekh, 2003;Field and Lahr, 2006;Rose and Petraglia, 2009;Armitage et al, 2011;Petraglia et al, 2011Petraglia et al, , 2012Delagnes et al, 2012;Petraglia, 2012, 2014;Crassard et al, 2013aCrassard et al, , 2013bScerri et al, 2014b). Surface freshwater availability, mediated by periodic incursions of increased rainfall, is likely to have been a critical control on the timing and routeways of hominin migrations across the mid-latitude SaharoArabian desert belt.…”

Cultural and human dynamics in southern Arabia at the end of the Middle Paleolithic

“…392 m. Three sites (Shi'bat Dihya 1: SD1, Shi'bat Dihya 2: SD2, Al-Sharj1: AS1) have been investigated, ranging between ca. 60 and 50 ka (see Delagnes et al, 2012), and scattered lithics have been found in a lower geological unit dated to ca. 85 ka.…”

“…These stages correspond to hyperarid episodes with subsequent cessation of alluvial sedimentation and formation of desert pavements. The incision phases in the basin that separate the different sedimentary members are assumed to result from high water flux periods in the Delagnes et al, 2012) and the Wahiba sands of Oman (from Preusser, 2009). The content of biogenic CaCO 3 in core 70 KL is inversely correlated with the contribution of dust in the Arabian sea (from Leuschner and Sirocko, 2003); the curve of the summer insolation difference between 30 S and 30 N is a measure of the intensity of the Indian monsoon (from Leuschner and Sirocko, 2003); after Sitzia et al, 2012. Wadi, corresponding to the humidity peaks documented during MIS 5e (128e120 ka), MIS 5c (110e100 ka) and MIS 5a (90e74 ka) in the Arabian Peninsula, as well as during the beginning of the Holocene (Fleitmann and Matter, 2009;Fleitmann et al, 2011;Rosenberg et al, 2011).…”

“…SD1 lithic products: pointed flakes (aec, g, h), pointed flakes with abrupt lateral edges (d, e), "narrow sided" core (f), centripetal recurrent Levallois flake (i), denticulated tool (j), cortical blade (k), thin and rectilinear blade (l), large thick blades (m, n); drawings by J. Jaubert, after Delagnes et al, 2012. yielded so far any evidence of human presence in the entire peninsula. A discontinuous occupation of the Arabian Peninsula during the Middle Paleolithic is also suggested by a high technological diversity (Petraglia and Alsharekh, 2003;Rose, 2007a;Crassard, 2008;Petraglia and Rose, 2009;Delagnes et al, 2012) whose significance (diachronic changes vs. regional synchronic diversity) remains however questionable since it relies on few dated and stratified records. In between periods of moisture and hyper-aridity peaks, the Arabian populations endured a series of climate and environmental degradations which may have resulted in contractions of settlements into environmental refugia (Bailey, 2009;Rose and Petraglia, 2009;Rose, 2010).…”