Twenty stone tools believed to be the oldest discovered in Japan have been excavated from a mid-Paleolithic period geological layer, dating back 120,000 years, at an archeological site in Izumo, Shimane Prefecture, researchers said. According to a team of experts, led by Prof. Kazuto Matsufuji of Doshisha University, that has researched the Sunabara remains, the tools are tens of thousands years older than any previously discovered.
     The existence of stone tools dating back to the early and mid-Paleolithic period in this country was thrown into question in 2000, when a former deputy director of the disbanded Tohoku Paleolithic Institute buried stone tools and later recovered them, claiming they were unearthed from 700,000-year-old archeological remains in Kurihara, Miyagi Prefecture, and other sites. Archeologists say the latest discovery could change the way the era is studied.
     The tools are between 5.2 cm and 1.5 cm long and made of quartz or rhyolite. Their surfaces indicate that they were chipped into shape. The excavation site is located on a slope in a hilly area. In August, Toshiro Naruse, a professor emeritus of Hyogo University of Teacher Education and a physical geography expert, discovered a knife-shaped stone tool at the site. Naruse asked Matsufuji and other researchers to research the area, leading to 19 other stone tools being discovered there. The age of the tools was determined by examining the volcanic ash layer just above the layer from which these tools were excavated.

Sources: Daily Yomiuri Online, Associated Press (30 September 2009)