Archaeologists have discovered a unique artifact in the Konso Formation in southern Ethiopia - a bone hatchet made by Homo Erectus. Despite the fact that this tool was widely used 1-2 million years ago, all previously found samples were exclusively stone. Prior to this discovery, only one ax was known, made from an elephant bone, found in the Olduvai Gorge in Tanzania. And now there are two of them, but both are very different.
Archaeologist from Tohoku University (Japan) Katsuhiro Sano compared the find with the bones of famous large animals and came to the conclusion that the starting material was the hippopotamus femur. In those days, this area of Ethiopia was a "patchwork swamp" with large volumes of clean water and flooded meadows - a paradise for hippos. And volcanic activity in the region from century to century changed the relief of the area and blocked the access of H. Erectus to deposits of good stone.
It is very interesting that the ax is made according to the Acheulean culture technologies, which are poorly suited for processing bones, but allows you to form a long cutting edge. Initially, the master cut off a large piece of a suitable shape from the workpiece, and then, with a series of light blows, chipped off layer by layer to form the working part of the ax. In the find, it is about 5 cm long and has obvious signs of wear, typical for butchering animal carcasses. Probably, the ax was owned by a skilled hunter, who was very proud of his light and sharp tool.
At the same time, there are no traces of heavy blows on the ax, which the bone would not withstand, it was not used for rough work. That is, the creator of the ax was well versed in the properties of the material, he understood the difference between the sharpness and fineness of the blade and the durability of the tool. Perhaps the ax from the bone of a hippopotamus was made as an experimental one, or it is one of the few successful samples that other craftsmen could not copy.