Rapid environmental change is a catalyst for human evolution, driving dietary innovations, habitat diversification, and dispersal. However, there is a dearth of information to assess hominin adaptions to changing physiography during key evolutionary stages such as the early Pleistocene. Here we report a multiproxy dataset from Ewass Oldupa, in the Western Plio-Pleistocene rift basin of Olduvai Gorge (now Oldupai), Tanzania, to address this lacuna and offer an ecological perspective on human adaptability two million years ago. Oldupai’s earliest hominins sequentially inhabited the floodplains of sinuous channels, then river-influenced contexts, which now comprises the oldest palaeolake setting documented regionally. Early Oldowan tools reveal a homogenous technology to utilise diverse, rapidly changing environments that ranged from fern meadows to woodland mosaics, naturally burned landscapes, to lakeside woodland/palm groves as well as hyper-xeric steppes. Hominins periodically used emerging landscapes and disturbance biomes multiple times over 235,000 years, thus predating by more than 180,000 years the earliest known hominins and Oldowan industries from the Eastern side of the basin.

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The Mlambalasi rockshelter in the Iringa

Highlights• Quartz-rich raw materials were extensively exploited in the African Early Stone Age.• Few studies have characterized quartzitic outcrops as primary source areas.• Macroscopic, petrographic, and EDXRF data used to fingerprint quartzitic outcrops at Oldupai.

Oldupai Gorge is located within the Ngorongoro Conservation Area, a UNESCO World Heritage Site in northern Tanzania along the western margin of the East African Rift System. Oldupai's sedimentary record contains inter-stratified stone tool industries associated with the Earlier, Middle, and Later Stone Age. While diachronic technological change is perceptible, the totality of locally available rocks remained largely unchanged through time. Here, thin section petrography, Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy, and Electron Probe Micro Analysis were employed to characterize source lithologies in the Oldupai region. One of our goals was to determine if outcrops have rock types with unique mineral assemblages amenable for sourcing lithic artifacts. Petrographic analysis of 62 lithologic samples collected in primary and secondary positions reveal discriminatory differences. More precisely, five outcrops have quartzites with unique mineral assemblages, five outcrops have meta-granites with unique mineral assemblages, Engelosin phonolite samples are texturally and mineralogically unique, and magmatic samples recovered in secondary position may be sourced to their volcanic center. Our results demonstrate it is feasible to discriminate source materials using mineralogy, which implies that sourcing lithic artifacts is possible. For proof of concept, we assign the source/s of previously described fuchsitic quartzite artifacts from three archaeological sites at Oldupai to two nearby outcrops. Additional archaeological testing will allow researchers to glean new understandings of hominin behavior and stone procurement in the Oldupai paleobasin.