TOKYO, JAPAN—According to a Science News report, paleoanthropologists Katsuhiro Sano of Tohoku University and Gen Suwa of the University of Tokyo have identified a 1.4-million-year-old hand ax made from a hippo’s leg bone at Ethiopia’s Konso-Gardula site. Tools at the site are thought to have been crafted by the human ancestor Homo erectus. The study suggests that the ax's oval shape was crafted by striking off the leg bone with one blow from a stone or bone hammer, and then chipped into its final shape with additional blows. Wear on the ax indicates it was used to cut or saw. The researchers explained that when combined with the variety of stone tools recovered from other Homo erectus sites in East Africa, the bone hand ax suggests that Homo erectus technology could have been more sophisticated and versatile than previously thought. To read about the recent find of the last known members of Homo erectus, go to "Around the World: Indonesia."