Peking Man (Sinanthropus pekinensis) was a type of Homo erectus. A group of fossil specimens was discovered between 1923 and 1927 during excavations at Zhoukoudian (Chou K'ou-tien) near Peking (now Beijing), China. The finds were then dated from roughly 800,000 years ago, although a new 26Al/10Be dating suggests they may be as much as 680,000-780,000 years old. Between 1929 and 1937, 15 partial craniums, 11 lower jaws, many teeth, some skeletal bones and large numbers of stone tools were discovered in the Lower Cave at Locality 1 of the Peking Man site at Zhoukoudian, near Beijing, in China. Their age is estimated to be between 500,000 and 300,000 years old. The fossil skull discovered at Locus E in 1929 was an adolescent or juvenile with a brain size of 915 cc. The skull II, discovered at Locus D in 1929 but only recognized in 1930, was an adult or adolescent with a brain size of 1030 cc.