AsianScientist (Mar. 6, 2017) – Paleontologists from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have described two 100,000 year-old crania from Lingjing, Xuchang, China. Their findings, published in Science, provide crucial insight into the poorly understood period of human regional diversity 200,000 to 50,000 years ago.
The Xuchang 1 and 2 crania, excavated in situ in the Lingjing site in Xuchang County of Henan Province between 2007 and 2014, reflect eastern Eurasian ancestry in having low, sagittally flat, and inferiorly broad neurocrania. However, they also share occipital (suprainiac and nuchal torus) and temporal labyrinthine (semicircular canal) morphology with the Neandertals.
The Xuchang 1 and 2 crania were found broken, each cranium dispersed within a circumscribed horizontal area. They were associated with a diverse macromammalian faunal assemblage, rich in Equus, Bos, Megaloceros, Procapra, Cervus, and Coelodonta.
The layer contains a Middle Paleolithic lithic industry, along with bone tools on diaphyseal splinters, and it has produced a consistent series of optically stimulated luminescence ages, placing the human remains at about 105,000 to 125,000 years, and the overlying layers have provided ages of about 100,000 and 90,000 years. The human crania are therefore securely dated to marine isotope stage (MIS) 5, within MIS 5e or 5d.
The Xuchang early Late Pleistocene archaic human crania exhibit a mosaic morphological pattern. They exhibit features that are ancestral and reminiscent particularly of early Middle Pleistocene eastern Eurasian humans, and derived and shared by earlier Late Pleistocene humans elsewhere, whether morphologically archaic or modern.
The endocranial volume of Xuchang 1 is about 1,800 cm3, at the high end of Neandertal and early modern human variation. Its neurocranium closely approximates the shape of those of Middle Pleistocene humans, especially eastern Eurasians.
In combination with these derived and ancestral features, the Xuchang crania also display two complexes that primarily align them with the Neandertals. They share occipital (suprainiac and nuchal torus) and temporal labyrinthine (semicircular canal) morphology with the Neandertals.
“This morphological combination, particularly the presence of a mosaic not known among early Late Pleistocene humans in the western Old World, suggests a complex interaction of directional paleobiological changes and intra- and interregional population dynamics,” said Dr. Wu Xiujie of the IVPP, project designer and co-corresponding author of the study.
“From their fossil record, eastern Asian late archaic humans have been interpreted to resemble their Neandertal contemporaries to some degree, with considerations of whether the fragmentary remains of the former exhibit features characteristic of the latter. Yet it is only with the discovery of two human crania (plus additional elements) from the Lingjing site in Xuchang County of Henan Province, China, that the nature of these eastern Eurasian early Late Pleistocene archaic humans is becoming clear,” said Wu.
The Xuchang crania therefore provide an important window into the biology and population history of early Late Pleistocene eastern Eurasian people. As such, they are a critical piece in our understanding of the human evolutionary background to the subsequent establishment of modern human biology across the Old World, a process that was already underway in eastern Africa and (apparently) further south in eastern Asia.
The article can be found at: Li et al. (2017) Late Pleistocene Archaic Human Crania from Xuchang, China.
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Source: Chinese Academy of Sciences.
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