The two Yunxian crania (EV 9001 and EV 9002) were found in 1989 and 1990 near Mitousi Village, Yunxian County, Hubei Province. They were described by Li and Etler, (1992) who argue that their morphology is consistent with Chinese Homo erectus and distinct from archaic Homo sapiens. Chen et al. (1996) report a mean ESR date from mammal tooth enamel at Yunxian of 581±93 ka. The range of the 10 samples listed by the authors is from 800±164 to 455±58 ka. Providing the dated fauna and the Yunxian hominids are contemporaneous this places Yunxian between Zhoukoudian and Gongwangling in the Chinese sequence.
The major difficulty in assessing the taxonomic affinity of the Yunxian crania is allowing for the extensive postdepositional, crushing, distortion and expansion. For instance, many of the features which are diagnostic of Homo erectus, including the angulation of the occipital and nuchal planes, endocranial volume and the morphology of the supraorbital torus, are poorly preserved in both Yunxian crania. As a result of this Zhang Yinyun (1995; 1998) has argued that several of the features claimed to support Homo erectus status can not really be assessed in the Yunxian crania. He argues that morphologically they are likely to be archaic Homo sapiens like Dali or Jinniushan rather than Homo erectus. Similarly, Wu and Poirier (1995) argue for a mixture of Homo erectus and H. sapiens features in Yunxian but to what extent the diagnostic traits have been influenced by postdepositional processes will never be known.
From my perspective, two factors support the Homo erectus status of the Yunxian crania. If the mean ESR date of 581 ka is meaningful this falls within the middle of the Chinese Homo erectus sequence and is several hundred thousand years older than the earliest dated examples of archaic H. sapiens (Jinniushan approximately 280 ka, Dali approximately 200 ka, Mapa approximately 132 ka). Secondly, if facial distortion is taken into account there is a remarkable similarity in both size and morphology between the facial skeletons of Sangiran 17 and Yunxian EV 90001 (see below). Neither look anything like Jinniushan or Dali.
Most recently Vialet et al (2010) used 3D imaging and reconstruction in an attempt to obtain more reliable information on the taxonomic status and anatomical details of Yunxian EV 9001. A worthwhile attempt, particularly when there had been little progress in the preceding 20 years, but ultimately the degree of distortion and fragmentation was an insurmountable obstacle. The authors conclude that they have added to knowledge of variability in Homo erectus, without really providing convincing evidence that this is the taxa to which the Yunxian hominins should be allocated.
I have not added a list of measurements for either EV 9001 or EV 9002 as I do not believe that the existing dimensions have much in common with how the crania appeared prior to deposition.
Comparison of Yunxian EV 9001 with Sangiran 17
Access to Yunxian
The Yunxian collection is housed in the Institute of Cultural Relics and Archaeology of Hubei Province, Wuhan, China. Research workers interested in access to Yunxian should write to Professor Li Tianyuan, Institute of Cultural Relics and Archaeology of Hubei Province, Wuhan 430077, China
References
Chen T, Yuang Q, Hu Y, and Li T (1996) ESR dating on the stratigraphy of Yunxian Homo erectus, Hubei, China. Acta Anthropologica Sinica 15:114-118.
Li T, and Etler DA (1992) New Middle Pleistocene hominid crania from Yunxian in China. Nature 357:416-419.
Vialet, A. et al (2010) Homo erectus from the Yunxian and Nankin Chinese sites: Anthropological insights using 3D virtual imaging techniques. Comptes Rendus Palevol 9: 331-339.
Wu X, and Poirier FE (1995) Human evolution in China. Oxford: Oxford University Press.
Zhang Y (1995) Fossil human crania from Yunxian: morphological comparison with Homo erectus crania from Zhoukoudian. Acta Anthropologica Sinica 14:1-7.
Zhang Y (1998) Fossil human crania from Yunxian, China: Morphological comparison with Homo erectus crania from Zhoukoudian. Human Evolution 13:45-48.