Ledi Geraru Teeth Indicate Coexistence of Homo and Australopithecus

A discovery at a remote site in Ethiopia is reshaping how scientists picture early human evolution. Thirteen fossil teeth dated to between 2.8 million and 2.6 million years ago have been found at LediGeraru in the Afar Region, revealing that two distinct hominin lineages—early members of the Homo genus and an as-yet-unnamed Australopithecus species—lived in close proximity. The find reinforces the view that human evolution was not a simple, linear march but a complex, overlapping forest of branches, with several hominin groups sharing the landscape in eastern Africa during this crucial period.

The teeth were recovered from three adjacent layers of volcanic ash, a setting that allowed researchers to place each fossil within a precise time window. The oldest and youngest layers, dated to about 2.79 and 2.59 million years ago, yielded teeth attributed to Homo, while the middle layer, dated to roughly 2.63 million years ago, yielded Australopithecus teeth. This pattern suggests that Homo and Australopithecus inhabited the area at overlapping times, a conclusion that supports the idea of a “bushy tree” of hominin evolution rather than a single, ongoing progression from ape-like...