26Al/10Be burial dating and technological strategies of hominins at the Jijiazhuang Paleolithic site, Nihewan Basin, China: Implications for understanding Middle Pleistocene human adaptations in east Asia

With the discovery of more than a hundred Pleistocene Paleolithic sites, the Nihewan Basin of North China has become an area of reference for the study of human evolution and behavioral adaptations during and after the spread of hominins out of Africa and into Eurasia. However, most research has focused on the Early and Late Pleistocene archaeological record, whereas studies of the Middle Pleistocene sequence are relatively limited. Here we contribute to fill this gap by introducing the archaeological assemblage and 26Al/10Be burial dating of the newly discovered Jijiazhuang (JJZ) Paleolithic site. Systematic excavations in recent years have yielded wellpreserved stone artifacts and mammalian fossils in fluvio-lacustrine sediments at the site. Cosmogenic 26Al/10Be burial dating indicates that hominins occupied the site between 0.49 +/- 0.10 and 0.63 +/- 0.11 Ma, corresponding to the extra-long interglacial period of MIS 15-13. The JJZ lithic assemblage shows evidence of relatively longdistance resource procurement, and the increased number of retouched tools indicate standardized, extensive and refined modification, even shaping strategies. The JJZ lithic technology shows advanced features that may shed light on the regional emergence of Middle Paleolithic technologies, in a paleoecological context where the extra-long duration of interglacial/mild stadial climate events (MIS 15-13) may have provided favorable conditions for increased technological capabilities among Middle Pleistocene hominins from the Nihewan Basin. Our study is the first to present a detailed techno-typological analysis of a Middle Pleistocene lithic assemblage in the Nihewan Basin and contributes to the characterization of technological adaptions in the high latitudes of East Asia.