Fossil Foot Identified as Belonging to Australopithecus deyiremeda

Recent fossil discoveries in Ethiopia have conclusively linked a 3.4-million-year-old partial foot, known as the Burtele foot, to the ancient hominin species Australopithecus deyiremeda. This finding provides clear evidence that multiple hominin species coexisted in the region during the Middle Pliocene epoch.

The Burtele foot, unearthed in 2009 in the Afar region, exhibited an opposable big toe—a trait associated with tree-climbing abilities—distinct from the bipedal adaptations of Australopithecus afarensis, the species to which the famous 'Lucy' belongs. In 2015, researchers identified A. deyiremeda based on jawbone fossils found nearby but could not definitively associate the Burtele foot with this species at that time.

In a study published in Nature, a team led by Yohannes Haile-Selassie reported the discovery of additional fossils, including a jawbone with 12 teeth, in the same stratigraphic layer as the Burtele foot. These findings enabled the researchers to confidently attribute the foot to A. deyiremeda. Haile-Selassie stated,

"We have no doubt about the Burtele foot belonging to the same species as these teeth and the jaw."

Further analysis revealed that A. deyiremeda was more primitive than A. afarensis, with a diet primarily consisting of leaves, fruits, and nuts from trees and shrubs. The species' grasping big toe suggests a lifestyle that included significant time spent in trees. This contrasts with A. afarensis, which was more adapted to bipedalism and likely occupied different ecological niches.

The coexistence of these two species in the same region underscores the complexity of human evolution. Haile-Selassie emphasized,

"Co-existence is deep in our ancestry."

This discovery challenges the previously held notion that A. afarensis was the sole hominin species in the area during that period and prompts a reevaluation of the evolutionary pathways leading to modern humans.