Japan’s oldest known human remains have been found in a cave on Ishigaki Island in Okinawa Prefecture, announced a University of Tokyo researcher. The oldest bone fragments uncovered are estimated to be 24,000 years old.
Associate Professor Minoru Yoneda analyzed 25 human bone fragments that had been dug up from Shirahosaonetabaru cave before 2010. The bottom layer was estimated to be 20,000 to 24,000-year-old. By using radiocarbon dating Yoneda established that a rib bone fragment from the bottom layer is about 24,000 years old, while three other fragments are about 20,000 years old.
The same cave had produced other 20,000-year-old human remains, the previously oldest known traces of human existence in Japan. A past survey had found that one of the six pieces of human bones found at the site dated back some 20,000 years through direct measurement of radioactive carbon of collagen extracted from those bones. However, researchers couldn’t determine the geological layer that hosted those remains.
The oldest human remains ever found on the main Japanese islands were established by radiocarbon dating to be 18,000 years old. They were dug up in Hamamatsu in Shizuoka Prefecture. The acidity of the soil on many parts of the main Japanese islands is thought to be a limiting factor in discovering Paleolithic remains.
