Sambungmacan is an open site on the south bank of the Solo River in central Java. An adult Homo erectus calotte, Sambungmacan 1, was discovered in 1973. Two other crania, Sambungmacan 3 (Delson et al, 2000, 2001; Marquez et al., 2001) and 4 (Baba et al., 2003) have also been recovered, the former being purchased in a New York curio shop after it had been removed from Java without a permit (Delson et al., 2000). In common with the other Javan H. erectus localities, the dating of Sambungmacan is problematic. The site was originally thought to be of lower-middle Pleistocene age, but ESR, Ar/Ar and U-series dates have provided conflicting results (Swisher et al., 1996; Indriati et al., 2011).
In 1996 Swisher and colleagues reported ESR and U-series dates for both Sambugmacan and Nagandong (Santa Luca, 1980) of 27-53 ka, indicating the post-Toba survival of H. erectus in Java and the overlap of H. erectus and H. sapiens populations in Asia. One of the implications of this remarkably young date, was that it was extremely unlikely that Javan H. erectus was ancestral to Australasian H. sapiens, as claimed in the multiregional model (Thorne and Wolpoff, 1981) as anatomically modern H. sapiens were known to be in the region at 40-50 ka (Lake Mungo and Niah Cave). There was simply too little time for Java H. erectus to have evolved into modern human form, and the genetic (Rasmussen, et al., 2011), behavioural and hominin fossil (Herto, Aduma and Klassies River Mouth) evidence indicated that African H. sapiens predated Sambungmacan by ~100 ka (White et al. 2003; Haile-Selassie et al., 2004; Rightmire and Deacon, 1991).
Most recently, a team containing some of the original authors, have reported new 40Ar/39Ar, ESR and U-series dates for Ngandong, Sambungmacan and the faunal site of Jigar (Indriati et al., 2011). They argue that the different dating methods indicate an age in the range of 546-612 ka, placing these three sites in the Middle Pleistocene and significantly older than previous estimates. However, they caution that the ESR/U-series date that complies with all modeling criteria is ~143 ka, still considerably older than the 1996 estimate of 27-53 ka. While the new estimates are more consistent with what you would expect from Sangiran, I am not convinced that any of them provide an accurate age, or even a range of ages, for either Sambungmacan or Ngandong. The precise relationship between the depositional history of these deposits and the fossils that they contain remains unknown, and direct methods of dating fossils of this age are problematic (Yokoyama et al. 2008).
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| Sambungmacan 1 |
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craniometric data for LB1 H. floresiensis, H. erectus and H. habilis |
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References
Chen, C.H., Lee, M.Y., Yang, T.F., Iizuka, Y., Wei, K.Y. 2000. Newly discovered eastern dispersal of the youngest Toba Tuff. Marine Geology 167: 303-312.
Haile-Selassie, Y. et al., 2004. Hominid cranial remains from Upper Pleistocene deposits at Aduma, Middle Awash, Ethiopia. American Journal of Physical Anthropology 123, 1-10.
Louys, J., 2007. Limited effect of the Quaternary's largest super-eruption (Toba) on land mammals from Southeast Asia. Quaternary Science Reviews, 26, 3108-3117.
Rasmussen, M., et al., 2011. An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia. Science 334, 94-98.
Reich, D., et al.., 2011. Denisova Admixture and the First Modern Human Dispersals into Southeast Asia and Oceania. The American Journal of Human Genetics 89, 516-528.
Rightmire, G.P. and Deacon, H.J., 1991. Comparative studies of Late Pleistocene human remains from Klasies River Mouth, South Africa. Journal of Human Evolution 20, 131-156.
White, T.D. et al., 2003. Pleistocene Homo sapiens from Middle Awash, Ethiopia. Nature 423, 742-747.
Yokoyama, Y., Falguères, C., Sémah, F., Jacob, T., Grün, R., 2008 Gamma-ray spectrometric dating of late Homo erectus skulls from Ngandong and Sambungmacan, Central Java, Indonesia. Journal of Human Evolution 55, 274-277.