Contact: Stephanie Stone
California Academy of Sciences
Caption: These two bones from Dikika, which have been dated to roughly 3.4 million years ago, provide the oldest known evidence of stone tool use among human ancestors. Both of the cut-marked bones came from mammals -- one is a rib fragment from a cow-sized mammal, and the other is a femur shaft fragment from a goat-sized mammal. Both bones are marred by cut, scrape, and percussion marks.
Credit: Dikika Research Project, California Academy of Sciences
Usage Restrictions: With credit to the Dikika Research Project, California Academy of Sciences
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