A foot fossil found in Ethiopia is rewriting part of the story of human evolution. The 3.4-million-year-old remains, discovered in the Burtele region in 2009, show clear differences from the well-known species Australopithecus afarensis, famously represented by the partial skeleton nicknamed “Lucy.”
This find, which researchers have now linked to a separate species called Australopithecus deyiremeda, suggests that more than one type of early human relative lived in East Africa during that period. The details of the discovery were published in the journal Nature, offering fresh insight into how our early ancestors lived and evolved.
One standout feature of the foot is an opposable big toe — similar to a thumb — which points to strong climbing abilities. This physical trait implies that this species likely spent more time in trees than Lucy’s kind, which mostly walked upright on the ground.
New species suggests a more complex evolution story
For many years, experts believed Australopithecus afarensis was the direct ancestor of all later human species. That idea began to shift when more fossils — including a jawbone with a set of teeth — were uncovered from the same region in Ethiopia. After further analysis, scientists determined that these remains belonged to a completely different species, now known as Australopithecus deyiremeda.
The differences between the two species show that early human evolution was far more diverse than once thought. According to John Rowan, a human origins researcher at the University of Cambridge, the evidence strongly supports the existence of closely related but physically different species living at the same time. Rowan, who was not involved in the research, explained that as more species are identified, it becomes increasingly difficult to trace a direct line of descent in human evolution.
Led by Yohannes Haile-Selassie of Arizona State University, the research team also examined how the two species shared the same environment without competing directly. Their findings suggest that A. deyiremeda may have lived mostly in wooded areas, while A. afarensis likely preferred more open landscapes. This difference in habitat use may have reduced competition and helped the species coexist.
Fossil clues offer glimpse into daily life of early human relatives
The study also looked closely at the fossilized teeth. Researchers found that A. deyiremeda had more rudimentary features, which may have suited a diet of fruits, leaves, and nuts. These traits, combined with its climbing ability, suggest that this species had a lifestyle that was quite different from Lucy’s.
Ashleigh Wiseman, a researcher at the McDonald Institute for Archaeological Research in Cambridge, pointed out that while the evidence is strong, identifying a species with certainty usually requires more complete skulls and skeletons. She emphasized that while the findings support the classification of a new species, there’s still room for interpretation as more fossils are studied.
This discovery adds a new branch to the human family tree and reinforces a key message: human evolution was not a straight line. Instead, it was a complex journey involving several species that adapted to their environments in unique ways.