Nanjing Man

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

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 (葫芦洞) on the Tangshan (汤山) hills in Jiangning District, Nanjing. 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]

Discovery

In 1992, Mu Xi-nan (穆西南), Xu Hankui (许汉奎), Mu Daocheng (穆道成), and Zhong Shilan (钟石兰) with the Nanjing Institute of Geology and Paleontology (NIGP) identified Hulu Cave near the Tangshan Subdistrict in Jiangning District, Nanjing (roughly 26 km (16 mi) east of the city center of Nanjing) as a mammalian fossil bearing site, and organised further excavations with the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) headquartered in Beijing. In March 1993, local labourer Liu Luhong discovered two partial skull fragments (Nanjing 1 and 2), the first retaining most of the face, and an upper molar (Nanjing 3).[1][3]

The mammal assemblage indicated Huludong was roughly contemporaneous with the Zhoukoudian cave site near Beijing, home of the Peking Man (the reason why the IVPP joined in the first place).

Age determination

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.[4]

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.[5] 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.[6]

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.[6] 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.[6] A scientific consensus on the dispersal of Homo sapiens throughout the globe was reached in the early 21st century.[7] However, the influence of East Asian Homo erectus subspecies on modern humans ancestry remains unclear.[7]

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.[8] A high diversity in cranial morphological features in Chinese subspecies of Homo erectus has been identified in a number of studies[8][3][9]

Present location

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

References

  1. ^ a b W. Rukang, L. Xingxue, "Homo erectus from Nanjing", PaleoAnthropology, 2003. 6 September 2017.
  2. ^ a b 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. ^ a b Liu, Wu; Zhang, Yinyun; Wu, Xinzhi (2005). "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. 127 (3): 253–262. doi:10.1002/ajpa.20066. PMID 15584056.
  4. ^ 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.
  5. ^ 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.
  6. ^ a b c Etler, DA (1984). "Homo erectus in East Asia: Human Ancestor or Evolutionary Dead-End?" (PDF). Athena Review. 4 (1). S2CID 9153290. Archived from the original (PDF) on 2019-02-20.
  7. ^ a b Stringer, C (2003). "Human evolution: Out of Ethiopia". Nature. 423 (6941): 693–695. Bibcode:2003Natur.423..692S. doi:10.1038/423692a. PMID 12802315. S2CID 26693109.
  8. ^ a b 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.
  9. ^ Zhang, Yinyun 张银运; Liu, Wu 刘武 (2007). "Nánjīng 1 hào zhílì rén tóugǔ yǔ Kěnníyǎ KNM2ER 3733 rénlèi tóugǔ huàshí de xíngtài bǐjiào" 南京 1 号直立人头骨与肯尼亚 KNM2ER 3733人类头骨化石的形态比较 [A morphological comparison of two homo erectus crania: Nanjing 1 and KNM2ER 3733]. Rénlèixué xuébào / Acta Anthropologica Sinica (in Chinese). 26 (3): 237–248.
  10. ^ "Tangshan Homo Erectus Fossil Museum". The Najinger. August 14, 2014. Archived from the original on 2017-09-08. Retrieved 6 September 2017.

External links