Homo sapiens bones in East Africa are at least 36,000 years older than when believed
Fossils from the earliest recognized Homo sapiens person in East Africa are more ancient than formerly believed.
A partial H. sapiens skull and associated skeletal parts discovered in 1967 in the Kibish rock development along Ethiopia’s Omo River date to a minimum of around 233,000 years earlier, pressing back the age of the fossils by 36,000 years or more. An age well going beyond 200,000 years for the Ethiopian fossils, referred to as Omo 1, fits with current fossil discoveries recommending that H. sapiens developed throughout Africa beginning approximately 300,000 years back ( SN: 6/7/17).
A volcanic eruption about 233,000 years ago left a layer of ash atop the sediment that yielded the Omo H. sapiens fossils, state volcanologist Céline Vidal of the University of Cambridge and coworkers. That ash layer showed a chemical finger print matching that of a volcanic crater situated 350 kilometers northeast of the fossil website. An enormous eruption there gushed ashes that wafted to Omo, the scientists state. Dating of solidified ash at the volcanic crater resulted in the brand-new age quote for the human fossils, the researchers report January 12 in Nature
Another Omo ash layer lying near the fossil-bearing sediment, however with unpredictable origins, had actually currently been dated to about 197,000 years back, supplying the previous age price quote ( SN: 2/22/05). All sediment ages count on steps of the decay of a radioactive kind of the component argon.
Further work will analyze whether ash layers listed below Omo’s fossil-ceding sediment arised from earlier volcanic blasts. “If effective, we may be able to bracket Omo 1 with an optimum age,” Vidal states.