Newly discovered Middle Pleistocene hominid-bearing deposits from the Lower Awash basin, Ethiopia

Abstract

Recent paleoanthropological surveys conducted in the Lower Awash basin (Afar Rift) have led to the discovery of new localities. Here we announce and describe the latest addition to the roster of hominid-bearing research areas in this basin. Located east of the modern Awash River and west of the Megenta mountain ridge, localities in the new research area contain extensive clay and silty-sand deposits variably capped by a widespread sandstone layer rich in archaeology and vertebrate fossils. Some of the localities are associated with volcanic tuffs suitable for radioisotopic age determination. A Middle Pleistocene antiquity is strongly inferred from the sampled fauna and archaeology; precise age estimates await results from ongoing tephra geochronological and geochemical analyses. Much of the archaeology falls under the conventional category of late Acheulean; assemblages identifiable as 'Middle' and 'Later Stone Age' are documented in a few localities. The vertebrate fauna from the closely probed Acheulean and hominid-bearing localities indicates a relatively wooded, near-water habitat. The cranial and postcranial fossil hominid (and faunal) remains from the new localities promise insights into the patterns of human evolution across the Middle Pleistocene, a period currently poorly understood. Similarly, the archaeological occurrences provide unique opportunities for testing outstanding hypotheses about the origin of nuanced technologies and behaviors across the later Middle Pleistocene.