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The Acheulean biface shown below, dating to approximately 350,000 B.P., is from a site at Atapuerca, a small town in the province of Burgos in northern Spain. Bifaces are two-sided stone tools produced by chipping away flakes ("lithic reduction"). So they are have flake scars on both sides. These hand axes were used for a variety of purposes. They are usually convex in shape. This particular ax is shaped from quartzite.
Acheulean Tools © Macroevolution.net