The Xujiayao site is located on the west bank of the Liyigou River, 1 km from Xujiayao Village, Gucheng District, Shanxi Province. Discovered in 1974, excavations were conducted in 1976, 1977 and 1979. The 27 hominid fossils recovered from Xujiayao include 12 pieces of parietal, with parietals 6 and 10 reasonably complete, two large occipital fragments, most of a temporal bone and part of the right maxilla from a 6-7 year old child. These were originally described by Jia et al. (1979) and Wu (1980). A detailed description in English can be found in Wu and Poirier (1995) who assign the Xujiayao remains to archaic Homo sapiens.
The Xujiayao locality contained a large quantity of vertebrate
fossils, all of which were fragmentary like the hominid remains.
Uranium series dating of rhinoceros teeth obtained a date of 104,000-125,000
years BP (Chen et al., 1984; Chen et al., 1982). Unfortunately,
the precise relationship of this date to the hominid fossils is
unclear, particulary when fossil fragmentation suggests some degree
of postdepositional disturbance at the site. A large quantity
of stone artifacts were also recovered from Xujiayao and these
have been discussed by Jia et al. (1979) and Wu et al. (1989).
Large tools are rare while scrapers are relatively common. A number
of bone and antler tools have been reported. Most recently, preliminary optically stimulated luminesence (OSL) dates have suggested an age of 60-69 ka (Wu and Trinkaus 2012). I have no idea which is a better indicator of the age of the hominin skeletal remains and artifacts, perhaps neither.
The infant left maxillary fragment consists primarily of the alveolar portion and three recently erupted permanent teeth. Teeth consist of a partially erupted central incisor, a canine, root of a deciduous second molar and first permanent molar. Both the central incisor and canine are distinguished by marked shovelling, with tooth and palate dimensions suggesting that the maxilla was from a male infant. Occipital n. 7 consists of a complete occipital plane and part of the nuchal region. The occipital torus is broadest centrally and narrows laterally. There is minimal angultion of the nuchal and occipital planes when viewed laterally. Occipital n. 15 is less complete and includes the left half and part of the right squama. Torus shape is similar to n. 7. Bone thickness in both occipitals is relatively great by modern East Asian standards (Brown 1987). Parietal n. 10 is complete except for its anterior part. The bone in this parietal is extremely dense and thickened. The parietal tuberosity is not prominent and parietal curvature suggests that this individual had maximum bi-parietal breadth located inferiorally. The posterior extension of the temporal line forms a pronounced crest. Bone thickness and suture development in parietal n. 6 suggests that it is from a juvenile. This parietal has a prominent tuberosity. Some dimensions of the Xujiayao bones and teeth are provided below. Most recently Wu et al. (2012) have described an enlarged parietal foramen in Xujiayao 11 parietals and Wu and Trinkaus have completed a new comparative description of the Xujiayao adult mandibular ramus.
Recent research and media coverage
Recently there has been a tendency to link a group of Chinese hominin fossils, including Xujiayao, Dali, Maba and Jinniushan, previously considered by some researchers to be "archaic Homo sapiens", with the Denisovians (Reich et al. 2010) (http://www.nature.com/nature/journal/v468/n7327/full/nature09710.html). However, apart from a few teeth, the Denisovians are only known from palaeo DNA. There is also a great deal of anatomical variation in the Chinese "archaic Homo sapiens" group. It will be interesting to see how this plays out over the next decade, or so.
Access to Xujiayao
The Xujiayao collection is housed in the Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China. Research workers interested in access to Xujiayao should write to Professor Wu Xinzhi, Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica, PO Box 164, Beijing, Peoples Republic of China.
Brown P (1987) Cranial vault thickness in Northern Chinese, European and Australian Aboriginal populations. Acta Anthropologica Sinica 6:10-15.
Chen T, Yuan S, and Gao S (1984) The study of uranium series dating of fossil bones and an absolute age sequence for the main Paleolithic sites of north China. Acta Anthropologica Sinica 6:249-254.
Chen T, Yuan S, Gao S, Wang L, and Zhao G (1982) Uranium series dating of Xujiayao (Hsu-chia-yao) site. Acta Anthropologica Sinica 1:91-95.
Jia L, Wei Q, and Li C (1979) Report on the excavation of the Hsuchiayao Man site in 1976. Vertebrata PalAsiatica 17:277-293.
Reich D, Green RE, Kircher M, Krause J, Patterson N, Durand EY, Viola B, Briggs AW, Stenzel U, Johnson PLF et al. . 2010. Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature 468(7327):1053-1060.
Wu M (1980) Human fossils discovered at Xujiayao site in 1977. Vertebrata PalAsiatica 18:227-238.
Wu R, Wu X, and Zhang S, eds. (1989) Early humankind in China. Beijing: Science Press.
Wu X, and Poirier FE (1995) Human evolution in China. Oxford: Oxford University Press.
Wu X-J, Xing S, Trinkaus E (2013) An Enlarged Parietal Foramen in the Late Archaic Xujiayao 11 Neurocranium from Northern China, and Rare Anomalies among Pleistocene Homo. PLoS ONE 8(3): e59587. doi:10.1371/journal.pone.0059587
Wu X, and Trinkaus E (In Press) Xujiayao 14 mandibular ramus and Pleistocene Homo mandibular variation. Compt. Rend. Palevol.
Table 1. Some dimensions of the Xujiayao bones and teeth (mm)
|parietal n.6||parietal n.10|
|Thickness at lambda||7.3||10.2|
|Thickness at tuberosity||5.9||12.8|
|Thickness at vertex||6.8||8.0|
|Thickness at bregma||-||7.7|
|occipital n. 7||occipital n. 15|
|Thickness at lambda||11.0||10.4|
|Thickness at ext. protuberance||18.3||17.8|
|Thickness at int. protuberance||17.4||16.4|
|first molar||isolated m2|