On this day, 32 years ago, on October 31, 1993 (September 17, 1993 in the lunar calendar), a 2.5 million-year-old human jaw bone fossil was unearthed. In late October 1993, paleontologists from Germany, the United States and Malawi discovered a 2.5-million-year-old human jawbone fossil near the west bank of Lake Malawi in East Africa. According to the British magazine Nature, this jaw bone fossil is one of the oldest human fossils ever found. It belongs to a little-known branch of humans-the Rudolphensis. Scientists believe that the direct ancestor of modern humans was the Rudolphensis, not the tool-making habilis originally thought to be the person who could make tools. Therefore, this discovery may lead to modifications in human evolutionary history. Bernard Wood, professor of anthropology at the University of Liverpool in the United Kingdom, said the Rudolphensis's teeth were wide and flat, indicating that they lived on grains, nuts, fruits and vegetables. They may have their own social organization, similar to chimpanzees. German paleontologist Friedman-Schrenk and colleagues who participated in the discovery believe that their findings provide support for the belief that early humans originated in East Africa, but when climate conditions were suitable at the end of the Pliocene, human ancestors, including animals, made large-scale migrations from East Africa to southern Africa. The location where the jaw bone fossils were discovered this time is about 2400 kilometers away from the areas where human fossils were found in northern Ethiopia and southern Africa, and no human fossils have been found here before. So this discovery provides a geographical bridge between north and south.