Ancient teeth reveal hominin overlap in Ethiopia

The fossil record in eastern Africa shows multiple hominin lineages living at the same time.

Ancient teeth reveal early hominins overlapped in Ethiopia

Two lines of evidence come from Ledi-Geraru in northeastern Ethiopia. Scientists uncovered teeth that belong to a Homo species dating to about 2.59 million years ago and teeth of an australopithecine around 2.63 million years ago. The site previously yielded the earliest Homo jaw dating to about 2.78 million years. Taken together, the finds indicate that Homo and Australopithecus coexisted in eastern Africa and that the fossil record at this site captures a moment when these lineages were still distinct but living in the same landscapes. The discovery narrows the gap between the first Homo and the australopithecines and suggests a more complex picture of early human evolution.

Researchers caution that the teeth cannot yet be assigned to named species. The australopithecine teeth do not match Lucy or other well known members of Australopithecus afarensis. The exact identity of the Homo teeth remains unresolved, and the researchers say more fossils are needed to map how these groups interacted. The Ledi-Geraru finds highlight a broader regional diversity in eastern Africa and reinforce the view that evolution followed multiple paths rather than a single ladder.

These results push us to rethink the pace and pattern of early human evolution. The idea of a straight line from Lucy to later Homo is replaced by a bushy tree with many branches, some of which overlap in space and time. If two lineages shared the same landscape, it changes how we interpret competition, resource use, and cultural development. The finding also stresses the challenge of defining species from teeth and jaws alone.

More fossils at Ledi-Geraru and nearby sites are essential to resolve the identities and relationships of these early humans. The story also places eastern Africa as a key cradle of diversity rather than a simple waypoint. For the public, it highlights that big questions about human origins are ongoing and that science evolves with new evidence.

Highlights

The fossil map of our origins keeps widening with every new find.