Omo Kibish, Ethiopia

Omo Kibish is group of archaeological sites and hominin fossil occurrences in the Lower Omo River Valley in Ethiopia dating to between 100 and 195 ka (Vidal, C. M., Lane, C. S., Asrat, A., Barfod, D. N., Mark, D. F., Tomlinson, E. L., Tadesse, A. Z., Yirgu, G., Deino, A., Hutchison, W., Mounier, A., & Oppenheimer, C. (2022). Age of the oldest known Homo sapiens from eastern Africa. Nature. https://doi.org/10.1038/s41586-021-04275-8.). The sites discussed here (hereafter “Kibish sites”) all lie within about 10 km of 5.41° N, 35.92° E on both sides of the Omo River. Located in Ethiopia’s Southern Nations, Nationalities, and People’s Region and on the traditional homelands of the Nyangatom (Bumi) and Mursi peoples, Omo Kibish is widely regarded as one of the most remote and difficult-to-reach places in Ethiopia. Perhaps for this reason, Omo Kibish has seen only episodic paleoanthropological investigations. Although there are a few Holocene-age sites in the area, this entry focuses only on the Pleistocene sites, sites associated with some of Africa’s oldest reliably dated Homo sapiens fossils. The Omo Kibish fossils and archaeology provide a snapshot of human behavior during the early phase of Homo sapiens’ evolutionary emergence in Eastern Africa. That snapshot shows more “modern-looking” people (e.g., Omo 1) living contemporaneously with more “archaic-looking” ones (e.g., Omo 2), a pattern in increasing concordance with the emerging picture of humanity’s “mosaic” African origins. Faunal remains from these sites preserve many remains of arid-land fauna (zebra, rhino, hartebeest, topi, Grant’s and Thompson’s gazelle, gerenuk) and riverine and aquatic species (hippopotamus, crocodile, giant forest hog). These fossils suggest that the ancient Omo River offered early humans not only potable water in an arid landscape, but also a wide array of mammals, reptiles, fish, birds, fruits, nuts, and plant underground storage organs. The Kibish stone tool assemblages’ shared features include overwhelming use of local crypto-crystalline silicate rocks (mostly jasper, chert, chalcedony, fossil wood, and fine-grained volcanics, such as rhyolite) as well as basalt and silicified mudstone. These seem mostly to have been procured from local gravel sources. Core reduction strategies included both preferential and recurrent bifacial hierarchical (aka “Levallois”) core reduction.