此前，关于我们祖先或其亲缘种使用工具的最早证据来自埃塞俄比亚阿瓦什河谷的两个地点。大约250万年前制造的石器在Gona被发现，时间大致相同的、有切痕的骨头在附近的Bouri被发现。怀疑古猿使用工具的时间甚至要更早的观点，现已被在阿瓦什河谷下游地区一个名叫Dikika的地方所获得的发现证实：这里发现的是来自大型有蹄动物的两块骨头，上面有切痕（见本期封面图片），这与古猿利用石质工具来从骨头上剔肉和从骨头里取骨髓的猜测是一致的。
这些有切痕的骨头距今大约340万年，很可能是“阿法南方古猿”(Australopithecus afarensis)的活动所留下的结果，该古猿是已知当时生活在阿瓦什河谷的惟一古猿，也是著名的古猿“Lucy”（来自Hadar）和年轻的“Selam”（或称DIK-1-1，来自Dikika）所属的有名物种。（生物谷Bioon.com）
生物谷推荐原文出处：
Nature doi:10.1038/nature09248
Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia
Shannon P. McPherron,Zeresenay Alemseged,Curtis W. Marean,Jonathan G. Wynn,Denné Reed,Denis Geraads,René Bobe& Hamdallah A. Béarat
The oldest direct evidence of stone tool manufacture comes from Gona (Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago1. At the nearby Bouri site several cut-marked bones also show stone tool use approximately 2.5?Myr ago2. Here we report stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia, a research area close to Gona and Bouri. On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access. The bones derive from the Sidi Hakoma Member of the Hadar Formation. Established 40Ar–39Ar dates on the tuffs that bracket this member constrain the finds to between 3.42 and 3.24?Myr ago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39?Myr ago. Our discovery extends by approximately 800,000 years the antiquity of stone tools and of stone-tool-assisted consumption of ungulates by hominins; furthermore, this behaviour can now be attributed to Australopithecus afarensis.
