Sinanthropus

Skull of "Homo erectus pekinensis", formerly as S. pekinensis

*Sinanthropus* is a dubious genus of hominid that lived in China during the Pleistocene.

## History

The first *Sinanthropus* is now known as the Peking Man, found by Otto Zdansky near Chou K'ou-tien, China after Johan Gunner Andersson et al. started excavations at the start of the 1920s. After, many finds would follow. Davidson Black first identified then as *Sinanthropus*. Many parts of the Peking Man were lost during WWII when they were transferred to the United States. After the initial find, many more Sinanthropus were found and classified. In 1963, the Yuanmou Man was found and the Nanjing Man in 1993. Around 40 individuals of Sinanthropus were from the Peking Man, a mandible and cranium of the Lantian Man, two incisors from the Yuanmou Man and two crania from the Nanjing Man. Because of the variety of parts from Chou K'ou-tian, Henri Breuil (1929) suggested they were cannibals, based on the incompleteness and trauma endured. However, it was suggested this was due to animal scavenging, likely due to hyenas. One 2001 study linking bone damage to hyenas, which strongly supported this theory.

After *S. pekinensis*, Black concluded it was a "missing link" in human evolution. He used it as evidence humans evolved in Asia. However, Franz Weidenreich suggested *Sinanthropus* could be an ancestor to modern Chinese people based on facial characters, but this is now invalid since Out of Africa is seen as the most likely theory. Thus, no specific hominid is the ancestor for modern races, since we all evolved from a single (African) ancestor.

## Description

*Sinanthropus* has two phenotypic traits: and erect posture and similar limbs and body to modern humans, but having different cranial features. The average cranial capacity is 1075cc, considerably smaller than modern humans, who have 1350cc. They have a very broad face, and cheekbones which were sharp and oriented frontally. Their forehead hangs low, the supraorbital ridge is enormous and forward-protruding and large nasals and teeth. Weidenreich calculated *Sinanthropus*' stature to be 156 centimeters for males and 144 centimeters for females. This differs from Soviet anthropologists, who estimated 162 centimeters in males and 152 in females. *Sinanthropus* has a differing jaw from gorillas, a cranial size similar to *Pithecanthropus* and smaller molars than the latter. Sinanthropus had teeth larger than Neanderthals. The upper canine was long, wide and similar to a tusk. Sinanthropus was differentiated by the size of the fragments found, with teeth differing in size throughout the genus, until the species was synonymized and fell into disuse.

It is likely the remains were brought into a cave manually, since the bodies show signs of separation, severed rather than decayed.

## Classification

Papers on *Sinanthropus* were published during the 1930s, comparing it to other hominids. Weidenreich frequently contributed and is blamed for the controversy around *Sinanthropus*. When he compared *Sinanthropus* and *Pithecanthropus* in a paper, he mentioned cranial size, jaw proportions and teeth size. Another researcher examined the remains, concluding they were "clearly Neanderthaloid". These two debates sparked the question if *Sinanthropus* was a valid genus. It was found to be the same as *Homo erectus*, and was synonymized and fell into disuse.

## References

1. ↑ http://www.math.chalmers.se/~ulfp/Review/pekingman.pdf
2. ↑ Woo, J.K. (1960). "The unbalanced development of the physical features of Sinanthropus pekinensis and its interpretation". Vertebrata PalAsiatica. 4: 17–26.
3. ↑ https://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330390111
4. ↑ Cheng-Chih, H. (1973). "Ape-man teeth from Yuanmou, Yunnan". Acta Geological Sinica.
5. ↑ Lu-jin, Z. (2003). "The Significance of the Discovery and Researches of the Homo erectus From Nanjing". Geological Journal of China Universities.
6. ↑ Boaz, N.T.; Ciochon, R.L. (2001). "The Scavenging of 'Peking Man'". Natural History. 110: 46–51.
7. ↑ Wang, Q.; Sun, L. (2000). "Eightieth year of Peking Man: current state of Peking man and the Zhoukoudian site". Anthropological Review. 63: 19–30.
8. ↑ 8.0 8.1 https://www.nature.com/articles/144926a0
9. ↑ 9.0 9.1 https://onlinelibrary.wiley.com/doi/10.1111/j.1755-6724.1935.mp14004001.x
10. ↑ 10.0 10.1 https://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330020308