A new hominin from the Basal Member of the Hadar Formation, Dikika, Ethiopia, and its geological context.

In this paper we report for the first time hominin remains from the Basal Member of the Hadar Formation at Dikika, in the Awash Valley of Ethiopia, dating to greater than 3.4 Ma. The new fossil, DIK-2-1, is a fragment of a left mandible and associated dentition. The mandible is attributed to Australopithecus afarensis. However, the new fossil exhibits some metric and morphological features that have not previously been seen in the A. afarensis hypodigm, increasing the already impressive degree of variation in the mandibular sample of the species.