Fluvial sediments of the middle Atbara River Valley, eastern Sudan, contain abundant vertebrate fossils and stone tools. Previous work described two sedimentary units, Butana Bridge Synthem (BBS) Khashm El Girba (KGS), with three divisions each (BBS1-3 KGS1-3, from bottom to top, respectively). 230Th/U dating on bivalve shells suggested an age ∼126 ∼92 ka for basal KGS2 KGS3, respectively, mamm...