Sinanthropus

Of the four species placed within the genus Sinanthropus, the first to be found were remnants of the Peking man (Sinanthropus pekinensis). The first fossil was retrieved by Otto Zdansky (1894-1988) near the village of Chou K'ou-tien (China) after the Swedish Geologist and Archaeologist Johan Gunnar Andersson (1874-1960) and his colleagues instigated the excavations at the beginning of the 1920's. Many more finds would follow. The Canadian Davidson Black (1884-1934) was the first to identify the fossils as a new hominid genus, Sinanthropus. A substantial part of the originally discovered remains of the Peking man was lost during WWII, when the fossils were transferred to the United States.[4]

After the discovery of the Peking Man remnants, other fossils were found which were classified within the genus Sinanthropus. The discovery of the fossils following up the ones of the Peking man were the remnants of the Lantian man in 1963 and consequently the fossils of the Yuanmou man in 1965 and Nanjing man in 1993. The fossils of the Peking man were the most abundant compared to the other species within Sinanthropus with bones belonging to around 40 individuals.[5] From the Lantian man, a mandible and cranium were found,[6] from the Yuanmou man only two incisors[7] and the fossil record of the Nanjing man consists out of two skulls.[8] Because of the variety in different body parts found at the Chou K'ou-tien excavation site, the traumas which some of the remains suffered, and the incompleteness of some of the skeletons, Henri Breuil (1877-1961) suggested in 1929 that Sinanthropus species were cannibalistic. Opposing the cannibalism theory, the idea was raised that the damage on the remains could be the result of animal scavenging, most probably by the Hyena. A study performed in 2001 showed strong evidence for the animal scavenging theory by linking damage done to the bones to Hyena bite-marks.[9]

In accordance with the findings of the systematic studies on the fossils, Sinanthropus holds the following phenotypic features. Sinanthropus had an erect posture with similar limbs and trunk to those of modern man but had a different face and head characteristics. The average cranial capacity is assessed to be 1,075cc, which is considerably smaller than the size of the brain of modern humans (1350cc). The facial structure included an extremely broad face, cheekbones which were sharply angled and frontally orientated, a low forehead, enormous eyebrow bones (supraorbital ridges) which protruded forward, broad nasal bones, and big teeth. The stature of Sinantropus was calculated by Weidenreich to be 156 cm for males and 144 cm for females. This contrasts the claims of Soviet anthropologists, who suggested a higher stature, namely 162 cm for males and 152 cm for females.[5] More specificities described by researchers indicated that Sinanthropus had a different jaw than found in gorillas, similar cranial size to Pithecanthropus, and smaller molars than those found in Pithecanthropus.[11] Researchers were also able to conclude that the teeth found were larger in comparison to Neanderthal men found at the time and the upper canine was long, wide, and similar to that of a tusk.[3] At the time, the genus Sinanthropus was distinguished by the massiveness of the bone fragments that were found.[12] The difference in teeth size created variability among the genus.

In the 1930s, papers were published regarding the Sinanthropus and they sought to examine the new hominids and their similar features to other discovered hominids. Dr. Weidenreich was a well-known contributor who was also received blame for a controversy surrounding Sinanthropus. He wrote a research paper about the similarities found in Sinanthropus and Pithecanthropus, where he mentioned the cranial size, jaw proportions and teeth size.[11] Another researcher took an opposing stand and stated that Sinanthropus was “clearly Neanderthaloid”.[2] These two conversations may be responsible for sparking the question revolving if Sinanthropus was even to be considered a genus.[2]