Dali (fossil)

Dali Skull

Common name	Dali Skull
Species	Probably Archaic Homo sapiens
Age	209,000
Place discovered	China
Date discovered	1978
Discovered by	Shuntang Liu

The Dali Skull, or Dali Man , is a nearly complete fossilized skull, probably representing an early form of Archaic Homo sapiens which lived in the Late Middle Pleistocene period. It was discovered by Shuntang Liu in 1978 in Dali County in the Shaanxi Province of China

Although dating has been a subject of debate, the fossil is estimated to be about 209 000 years old, and is considered to be the most complete skull of that time period found in China.^[1] The Dali cranium is currently housed in the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China.

Characteristics of the Dali fossil

The Dali cranium is interesting to modern anthropologists as it is possibly an ideal specimen of an archaic Homo sapiens. It has a mixture of traits from both Homo erectus and Homo sapiens.^[2] The details of the face and skull are however distinct from European Neandertals and earlier European hominids like the finds from Petralona and Atapuerca.^[3]

Skull vault

The skull is low and long, though the posterior end of the skull is rounded, unlike the contemporary broad-based H. erectus or top-wide skull of modern humans. It does however bear a prominent sagital crest, a trait found in H. erectus but in few modern humans. The brain appears to have been sitting mainly behind the face, giving an extremely low forehead. The cranial capacity is estimated to around 1 120 cc, at the lower end of the modern human range, and upper end of the H. erectus range. The base of the cranium is less robust than in H. erectus.^[4] The posterior margin lacks the heavy neck muscle attachment seen in that group. Unlike the distinct tubular form seen in H. erectus, the tympanic plate is thin and foreshortened, a condition similar to that of modern humans.^[5]

Unlike H. erectus skulls, the Dali skulls lack the "pinched" look between the face and the cranial vault.

Face

The face is topped by massive brow ridges. The ridges curve over each eye, unlike the straight bar-like ridges seen at the Peking man material from Zhoukoudian. The curvature is more similar structurally to the brow ridges in archaic humans from Europe and Africa. The cheek bones are delicate, and the nasal bone flattened, again a curious combination of traits.^[2] During fossilization, the upper jaw has been fractured and dislocated upwards, giving the cranium the appearance of having a very short face. If reconstructed, the face would be probably be similar in overall dimensions to that of the Jinniushan man skull.^[4]

Interpretation

There has been considerable debate regarding how to classify the fossil in terms of species, with some anthropologists insisting it to be a regional variant of Homo heidelbergensis and others categorizing it as an early representative of Homo sapiens, and as such there is no current consensus on the species status of the Dali fossil.^[6] Some anthropologists, notably many Chinese representatives, cite the characteristics of the Dali cranium and other similar Chinese fossils of that era as evidence for genetic continuity in modern H. sapiens today, as Dali's traits are commonly found in modern Chinese H. sapiens populations. In turn, it is often argued that modern Chinese humans did not evolve in Africa, but instead evolved in China from a separate lineage of H. erectus.^[7] This position is consistent with the "Multiregional hypothesis," which states that different human populations across the planet had evolved with current racial characteristics in separate environments, and is contrary to the popular "Recent single-origin hypothesis," which asserts that modern H. sapiens evolved solely in Africa and spread throughout the planet during a recent exodus.

Other possible Dali-type finds

An assortment of primitive Homo skulls have tentatively been placed with the Dali find. The Maba Man, a 120 to 140 000 year old fragmentary skull from Guangdong in China shows the same general contours of the forehead.^[8] A partial female skeleton with skull from Jinniushan (also China) seems to belong to the same group, characterized by a very robust skull cap but less robust skull base.^[9][10][11] A possibly forth member could be the Narmada skull from the Madhya Pradesh in India, consisting of a sigle robust cranial vault.^[12]

The Denisova hominin, represented by a very robust finger bone found in the Altai mountains in Russia is quoted as likely linked to the Dali people. Surprisingly, DNA studies show the bone belong to a woman, with Mitochondrial DNA linking it to a very deep split in the human tree, at around 1 million years old.^[13] This would make the DNA erectus rather than heidelbergensis or other more recent splits.^[14] However, the analysis of the nuclear DNA points to a sister group relationship with the neanderthals.^[15]

References

1. ^ Xiao, J.L., Jin C., Zhu Y., "Age of the Fossil Dali Man in North-Central China deduced from Chronostratigraphy of the Loess-paleosol Sequence," Quaternary Science Reviews, Volume 21, Number 20 (12 November 2002), pp. 2191-2198
2. ^ ^{a b} Wu X. (1981): A well-preserved cranium of an archaic type of early Homo sapiens from Dali, China. Scientia Sinica no 24: pp 530-539
3. ^ Wu X (1988): Comparative study of early Homo sapiens from China and Europe. Acta Anthropologica Sinica no 7: pp 292-299
4. ^ ^{a b} Wu R. (1988): The reconstruction of the fossil human skull from Jinniushan, Yinkou, Liaoning Province and its main features. Acta Anthropologica Sinica no 7: pp 97–101.
5. ^ Etler, D.A. (2001).Picture Gallery of Fossil Hominoids and Hominids from China, from the Center for Study of Chinese Prehistory.
6. ^ Jurmain, Robert, Lynn Kilgore, Wenda Trevathan, Essentials of Physical Anthropology, Sixth Edition (Belmont: Thomson Wadsworth, 2006): 252-253.
7. ^ Wolpoff M.H., Wu X., & Thorne A.G. (1984): Modern Homo sapiens origins: a general theory of human evolution involving the fossil evidence from east Asia. In FH Smith and F Spencer (eds.): The origins of modern humans: a world survey of the fossil evidence. New York: Alan R. Liss, pp. 411-483.
8. ^ Maba skull, Australian museum
9. ^ Lu, Z. (1989): Date of Jinniushan man and his position in human evolution. Liaohai Wenwu Xuekan no 1, pp 44-55
10. ^ Wu, R-K (1988): The reconstruction of the fossil human skull from Jinniushan, Yinkou, Liaoning Province and its main features. Acta Anthropologica Sinica No 7, pp 97-101
11. ^ Brown, P.: Jinniushan skull
12. ^ Cameron, D., Patnaik, R. & Sahni, A. (2004): The phylogenetic significance of the Middle Pleistocene Narmada hominin cranium from central India. International Journal of Osteoarchaeology, vol. 14, Issue 6, pp 419-447 summary
13. ^ Reich D, Green RE, Kircher M, Krause J, Patterson N, Durand EY, Bence V, Briggs AW, Stenzel U, Johnson PLF et al. 2010. Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature 468:1053-1060
14. ^ Bower, B. (2010): Ancient DNA suggests new hominid line. Science News, Vol. 177 (9), p. 5
15. ^ Reich et al., Denisova Admixture and the First Modern Human Dispersals into Southeast Asia and Oceania, The American Journal of Human Genetics, doi:10.1016/j.ajhg.2011.09.005 , http://www.sciencedirect.com/science/article/pii/S0002929711003958 

See also

• List of fossil sites (with link directory)
• List of hominina (hominid) fossils (with images)

External links

• Dali

Coordinates: 34°52′N 109°44′E / 34.867°N 109.733°E / 34.867; 109.733