At a remote region in southwestern Ethiopia, the Omo River and its long-vanished tributaries have laid bare rugged bluffs and hillsides, exposing a layer cake of ancient sediments and the trapped remains of early humans. Before the Covid pandemic, Céline Vidal and colleagues journeyed to this site known as the Kibish Formation to work in scorching temperatures up to 110 degrees Fahrenheit, picking through the ashes of ancient volcanic eruptions to learn more about some of the oldest members of our species.
