In a thoughtful review of the chronology of Chinese Palaeolithic sites Chen and Zhang (1991) discuss the reliability of dating procedures and apparent discontinuities in the distribution of Homo erectusand early H. sapiens sites. They note two clusters within the age distribution of sites, one around 190 kyr and the other 110 kyr, with few sites in the 130-160 kyr and 50-90 kyr range (Figure 1). Chen and Zhang argue that the discontinuities are not simply the chance products of preservation. More likely they reflect the movement of hominids to warmer areas during periods of glacial maximum. An additional problem is that many of the sites which are beyond the range of radiocarbon dating can not be dated with a great deal of precision. Variation within the published dates is often extreme, for instance Yunxian has a geomagnetic date of 830-870 kyr and an electron spin resonance date on stratigraphically associated tooth enamel of 581 ±93 kyr (Chen et al. 1996). This is not problem peculiar to China but occurs wherever researchers are forced to deal with complex cave stratigraphy, or sediments which can not be dated using the K/Ar method (Brown 1998, Brown 2001).

The discontinuities described by Chen and Zhang occur at crucial time periods for discussion of the origins of modern humans in East Asia. Sometime after Xujiayao (Chen et al. 1982; Wu and Wu 1985) modern people appear in China, with the earlier hominid fossils from Maba (Wu and Pang 1959) and Dali (Wu 1981) anatomically intermediate between H. erectus and H. sapiens. However, an additional gap between the early Neolithic sites of Baoji (Yan et al. 1960) and Huaxian (Yan 1962), in the 5500 to 7000 years BP range (The Institute of Archaeology 1991), and the Upper Cave (Shandingdong) at Zhoukoudian is of equal importance. While the East Asian morphology of the skeletons recovered from these Neolithic sites has not been contested, most observers have trouble identifying East Asian features in the Upper Cave remains (Howells 1989; Kaminga and Wright 1988; Weidenreich 1939a; Brown 1998). The colonisation of the Americas by 11 kyr indicates an earlier date for the appearance of distinctively Mongoloid features, however, the earliest unequivocal evidence for anatomically Mongoloid people on the Asian mainland remains at 7000 years BP (Brown 1998).

The following two figures provide approximate dates for East Asian Pleistocene hominid localities and major Neolithic Sites. A detailed list of Chinese radiocarbon dates was published by the Institute of Archeology, Chinese Academy of Social Sciences, Beijing in 1991. Dates for the Pleistocene localities are constantly being revised but Chen and Zhang (1991) is a good place to start. The dates for Shandingdong, Liujiang and Minatogawa are discussed in Brown (1998). Dates for individual East Asian hominid sites are discussed in each of the sites listed in the East Asian fossil index. A review of the distribution of the dates can be found in Brown (2001).

Recent research and media coverage

Zhu, Z. et al. 2015. New dating of the Homo erectus cranium from Lantian (Gongwangling), China. J. Human Evolution 78:144-57. doi: 10.1016/j.jhevol.2014.10.001. Epub 2014 Nov 20

Abstract
The Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province is the oldest fossil hominin specimen from North China. It was found in 1964 in a layer below the Jaramillo subchron and was attributed to loess (L) L15 in the Chinese loess-palaeosol sequence, with an estimated age of ca. 1.15 Ma (millions of years ago). Here, we demonstrate that there is a stratigraphical hiatus in the Gongwangling section immediately below loess 15, and the cranium in fact lies in palaeosol (S) S22 or S23, the age of which is ca. 1.54-1.65 Ma. Closely spaced palaeomagnetic sampling at two sections at Gongwangling and one at Jiacun, 10 km to the north, indicate that the fossil layer at Gongwangling and a similar fossil horizon at Jiacun were deposited shortly before a short period of normal polarity above the Olduvai subchron. This is attributed to the Gilsa Event that has been dated elsewhere to ca. 1.62 Ma. Our investigations thus demonstrate that the Gongwangling cranium is slightly older than ca. 1.62 Ma, probably ca. 1.63 Ma, and significantly older than previously supposed. This re-dating now makes Gongwangling the second oldest site outside Africa (after Dmanisi) with cranial remains, and causes substantial re-adjustment in the early fossil hominin record in Eurasia.

http://www.ncbi.nlm.nih.gov/pubmed/25456822

Some useful references

Brown, P. 1998. The earliest East Asians: a view from the Late Pleistocene and Neolithic of China and Japan. In K. Omoto (ed.) Interdisciplinary Perspectives on the Origins of the Japanese. International Research Center for Japanese Studies, Kyoto.

Brown, P. 2001. Chinese Middle Pleistocene hominids and modern human origins in east Asia. In L. Barham and K. Robson-Brown (eds.) Human roots: Africa and Asia in the Middle Pleistocene. Western Academic and Specialist Press, Bristol.

Chen, T., Hedges, R. E. M. and Yuan, Z. 1989. Accelerator radiocarbon dating for the Upper Cave of Zhoukoudian. Acta Anthropologica Sinica 8:216-221.

Chen, T., Yang, Q., Hu, Y. and Li, T. 1996. ESR dating on the stratigraphy of Ynxian Homo erectus, Hubei, China. Acta Anthropologica Sinica 15:114-118.

Chen, T., Yuan, S., Gao, S., Wang, L. and Zhao, G. 1982. Uranium series dating of Xujiayao site. Acta Anthropologica Sinica 1:91-95.

Chen, T. and Zhang, Y. 1991. Palaeolithic chronology and possible coexistance of Homo erectus and Homo sapiens in China. World Archaeology 23:147-154.

Hedges, R. E. M., Housley, R. A., Bronk, C. R. and Van Klinken, G. J. 1992. Radiocarbon dates from the Oxford AMS system: Archaeometry Datelist 14. Archaeometry 34:141-159.

Hedges, R. E. M., Housley, R. A., Law, I. A., Perry, C. and Hendy, E. 1988. Radiocarbon Dates from the Oxford AMS System: Archaeometry Datelist 8. Archaeometry 30:291-305.

Kobayashi, H., Hirose, Y., Sugino, M. and Watanabe, N. 1974. TK-99. Radiocarbon 16: 384.

Matsu'ura, S. 1984. Fluorine dating of Upper Minatogawa man. Journal of the Anthropological Society Nippon 92: 111-112.

The Institute of Archaeology, CASS. 1991. Radiocarbon dates in Chinese Archaeology 1965-1991. Cultural Relics Publishing House, Beijing.

Wu, X. and Wang, L. 1985. Chronology in Chinese Palaeoanthropology. In R. Wu and J. W. Olsen (eds.), Palaeoanthropology and Palaeolithic Archaeology in the People's Republic of China, pp. 29-68. Academic Press, London.

Zhu, Z. et al. 2015. New dating of the Homo erectus cranium from Lantian (Gongwangling), China. J. Human Evolution 78:144-57. doi: 10.1016/j.jhevol.2014.10.001. Epub 2014 Nov 20

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