Five fossil tooth enamel samples collected from the stratum of the Nanjing Homo erectus were ESR dated The average age is 355±42ka
based on the early uranium-uptake model Additional uranium series measurement of fossil teeth confirms the appropriateness of the early uranium-uptake model for these ESR samples Considering also the uranium-series ages of two calcite samples from the flowstone covering the fossil-containing stratum
an age value of 350±50ka for the Nanjing Homo erectus stratum is evaluated
which means that the Nanjing Homo erectus appeared in the late stage of Peking Man and also in the stage of human evolution earlier than Hexian Homo erectus