PLEISTOCENE CLIMATE CHANGE AT THE PEKING MAN SITE, CHINA

In addition to contributing information about hominid migrations and behavior, stable isotope analysis of tooth enamel can provide valuable continental paleoclimate records. The area of Zhoukoudian, located 50 km to the southwest of Beijing, was occupied by Homo erectus pekinensis from about 500 ka to 230 ka and contains abundant faunal material appropriate for isotopic analysis. Previous paleoenvironmental studies indicate a relatively stable climate during this time, which spans three mild glacial and interglacial periods. Carbon and oxygen isotopes from the enamel of fossil herbivore teeth provide an independent means for reconstructing past environments. Carbon isotopes are used to examine the relative abundance of C3 and C4 plants in the diet of each herbivore. Oxygen isotopes can indicate a change in the temperature and/or precipitation at the site. Six species have been analyzed from Locality 1 and include Equus sanmeniensis, Dicerorhinus choukoutienensis, Megaloceros pachyosteus, Sus lydekkeri, and Cervus nippon. Equus values show a mixed C3/C4 diet, indicating the presence of both plant types in the area throughout the interval sampled. However, two deer sampled show decreasing δ¹³C values over time, suggesting a possible decrease in the relative amount of C4 plants in the area. Accompanying the decrease in warm season grasses is a decrease in δ¹⁸O values. Further microsampling should indicate whether this decrease is due to overall colder temperatures at the site or, more likely, an increase in the influence of the winter monsoons in northern China. Colder winters with a shorter growing period could have caused the area to become less suitable for Homo erectus pekinensis, possibly resulting in site abandonment.