Nanjing Man

Nanjing Man (Homo erectus nankinensis) is a subspecies of Homo erectus found in China. Large fragments of one male and one female skull and a molar tooth of H. e. nankinensis were discovered in 1993 in the Hulu cave on the Tangshan hills near Nanjing, the former capital city of China. The term Nanjing man is used to describe the subspecies of Homo erectus but is also used when referring to the three fossils. The specimens were found in the Hulu limestone cave at a depth of 60–97 cm by Liu Luhong, a local worker.[1] Dating the fossils yielded an estimated age of 580,000 to 620,000 years old.[2]

Nanjing Man
Temporal range: Pleistocene
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorhini
Infraorder: Simiiformes
Family: Hominidae
Subfamily: Homininae
Tribe: Hominini
Genus: Homo
Species:
†H. erectus
Subspecies:
†H. e. nankinensis
Trinomial name
Homo erectus nankinensis

Age determination

For the dating of fossils the carbon-14 method is often used, but this method is not applicable for fossils older than 60,000 years, which is the case for the Nanjing man. Researchers used mass spectrometric U-series dating to identify the age of the skulls. Best estimates date the skull to be at least 580,000 years old. This research, done in 2001 estimates the age of the skulls to be 270,000 years older than previous estimates, executed with the use of different dating methods like Electron spin resonance dating and alpha-counting U-series. However, by using mass spectrometric U-series dating, the age for the tooth found on the Nanjing site was estimated to be only 400,000 years old. Researchers propose that the enamel used to date the tooth may not have the same uranium uptake as the skulls, leading to the discrepancy in estimated age.[2] Another study from 1999 estimated one skull to be at least 500,000 years old, while they date the other skull being between 250,000 and 500,000 years old using the TIMS dating method.[3]

Impact of the Nanjing fossils

Homo erectus occupation of Eastern Asia was an established idea well before the discovery of Homo erectus nankinensis. Nanjing man is one of several middle Pleistocene dated Homo erectus fossil finds in eastern China, the most well known of which is Peking man.[4] However dating the Nanjing man fossils between 580,000 YA and 620,000 YA pushed the estimate for Homo erectus colonisation of eastern Asia almost 270,000 years earlier.[5]

The Nanjing man fossil discovery coincided with the paleo-anthropological debate on the population dynamics of modern humans and their relation to other species of the genus Homo. The characteristics of the new subspecies Homo erectus nankinensis and in particular the age of the fossils provided additional evidence which was used to support the multi-regional hypothesis.[5] The extended occupation of East Asia by Homo erectus suggested by the dating of the Nanjing fossils supports the hypothesis that a transitional species between Homo erectus subspecies of Asia and pre-modern Homo sapiens existed.[5] A scientific consensus on the dispersal of Homo sapiens throughout the globe was reached in the early 21st century.[6] However, the influence of East Asian Homo erectus subspecies on modern humans ancestry remains unclear.[6]

Morphological features of the Nanjing man fossils such as cranial capacity and the size a various cranial metrics differ significantly from other Chinese hominin subspecies. Despite this morphometric and morphological features fall well within the range expected for Homo erectus.[7] A high diversity in cranial morphological features in Chinese subspecies of Homo erectus has been identified in a number of studies[7][8][9]

Present location

The skull fragments collected at Hulu cave are currently displayed the Tangshan Homo erectus fossil museum along with other education information about Nanjing man and colonisation of China by Homo erectus.[10]

References
  1. W. Rukang, L. Xingxue, "Homo erectus from Nanjing", PaleoAnthropology, 2003. 6 September 2017.
  2. J. Zhao, K. Hu, K. D. Collerson, H. Xu, "Thermal ionisation mass spectrometry U-series dating of a hominid site near Nanjing, China" Archived 2017-09-08 at the Wayback Machine, Geology, 2001. 6 September 2017.
  3. Y.Wang, C. Hai, C. Luo, Y. Xia, J. Wu, J. Chen, "TIMS U-series ages of speleothems from the Tangshan caves, Nanjing", Chinese Science Bulletin, 1999. Retrieved 6 September 2017.
  4. P. Brown, "Chinese Middle Pleistocene hominids and modern human origins in east Asia.", Human Roots: Africa and Asia in the Middle Pleistocene, 2001. Retrieved 6 September 2017.
  5. Etler, DA (1984). "Homo erectus in East Asia: Human Ancestor or Evolutionary Dead-End?" (PDF). Gene.
  6. Stringer, C (2003). "Human evolution: Out of Ethiopia". Nature. 423 (6941): 693–695. doi:10.1038/423692a. PMID 12802315.
  7. X. Wu; R.L Holloway; L.A. Schepartz; S. Xing (2011). "A new brain endocast of Homo erectus from Hulu Cave, Nanjing, China". American Journal of Physical Anthropology. 145 (3): 452–460. doi:10.1002/ajpa.21527. PMID 21541930.
  8. W. Liu, Y. Zhang, X. Wu, "Middle Pleistocene human cranium from Tangshan (Nanjing), Southeast China: a new reconstruction and comparisons with Homo erectus from Eurasia and Africa", American journal of physical anthropology, 2005. Retrieved 6 September 2017
  9. Y. Zhang, W. Liu, [article_link "A morphological comparison of two Homo erectus Crania: Nanjing 1 and KNM-ER 3733."], Acta Anthropologica Sinica, 2007. Retrieved 6 September 2017
  10. "TANGSHAN HOMO ERECTUS FOSSIL MUSEUM" Archived 2017-09-08 at the Wayback Machine, The Najinger, August 14, 2014. Retrieved 6 September 2017
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