Ethiopian Fossil Teeth Show Homo and Australopithecus Overlapped 2.6 Million Years Ago
Updated
Updated · Ancient Origins · May 20
Ethiopian Fossil Teeth Show Homo and Australopithecus Overlapped 2.6 Million Years Ago
4 articles · Updated · Ancient Origins · May 20
Thirteen fossil teeth from Ethiopia’s Ledi-Geraru site indicate early Homo and an unidentified Australopithecus species lived in the same region about 2.6 million to 2.8 million years ago.
The Nature study identified distinct tooth patterns from both groups and found the Australopithecus remains were not A. afarensis, suggesting a previously unknown species that cannot yet be formally named.
Volcanic ash layers above and below the fossils let researchers date the sediments, while the finds add to earlier Ledi-Geraru discoveries including a 2.8-million-year-old Homo jaw and the oldest known Oldowan tools.
The evidence strengthens a broader view of human evolution as a branching process, with as many as four hominin lineages potentially overlapping in eastern Africa between 3.0 million and 2.5 million years ago.
If scientists still debate what makes an ancestor 'human,' how do we draw the line between Australopithecus and Homo?
How did Africa's shifting tectonic plates help forge the first humans while dooming their relatives?
With four hominin types sharing a landscape, did our ancestors outcompete their cousins or simply avoid them?
Ledi-Geraru’s 2.6–2.8 Million-Year-Old Fossils Uncover Unexpected Diversity in Early Human Ancestors
Overview
The Ledi-Geraru site in northeastern Ethiopia has become a key place for studying early human evolution. In 2018, field assistant Omar Abdulla discovered an ancient molar exposed by wind erosion, which led to the excavation of 13 fossilized teeth between 2015 and 2018. Scientists from the Ledi Geraru Research Project at Arizona State University analyzed these teeth and found evidence that both the earliest known members of the Homo genus and a previously unknown Australopithecus species lived there at the same time. This discovery shows that multiple human ancestors coexisted, revealing a more complex story of our origins.