Overview

• Thirteen fossil teeth excavated at Ledi-Geraru were precisely dated between 2.59 and 2.78 million years ago using argon-argon methods and paleomagnetic controls
• Dental morphology assigns ten of the teeth to an unrecognized Australopithecus lineage around 2.63 million years ago and three to early Homo individuals dated 2.78–2.59 million years ago
• The coexistence of distinct Australopithecus and Homo lineages in the Afar region underscores a branching model of human evolution rather than a straight line of descent
• Paleontologists note that the new Australopithecus taxon remains unnamed due to the lack of cranial and postcranial remains needed for a comprehensive anatomical description
• Teams have resumed excavations at Ledi-Geraru to recover additional fossils required to formally describe the new species and clarify its ecological interactions with early Homo