Archaic Human Skulls from China Reveal Complex Mix of Trends in Time and Space | Sci.News (original) (raw)

Two partial archaic human skulls unearthed in central China provide a new window into the biology and populations patterns of the immediate predecessors of modern humans in eastern Eurasia.

Virtual reconstructions of the Xuchang 1 and 2 skulls, superimposed on the archeological site where they were discovered. Image credit: Xiujie Wu.

The skull remains came from the Lingjing site in Xuchang County, Henan Province, China.

The fossils, named Xuchang 1 and 2, were analyzed by an international team of researchers from Washington University in St. Louis, Peking University, Henan Provincial Institute of Cultural Relics and Archaeology, Institute of Vertebrate Paleontology and Paleoanthropology and the University of the Chinese Academy of Sciences.

The findings were published in the March 3, 2017 issue of the journal Science.

“The biological nature of the immediate predecessors of modern humans in eastern Eurasia has been poorly known from the human fossil record,” said Washington University Professor Erik Trinkaus, a corresponding author of the study.

“The discovery of these skulls of late archaic humans substantially increases our knowledge of these people.”

The Xuchang 1 and 2 skulls were found broken, each specimen dispersed within a circumscribed horizontal area. They were associated with stone and bone tools, and a diverse macromammalian faunal assemblage, rich in Equus, Bos, Megaloceros, Procapra, Cervus, and Coelodonta.

Dated to 105,000 to 125,000 years ago (early Late Pleistocene), the skull remains exhibit a mosaic of features with differences from and similarities to their western contemporaries:

(i) with western Eurasian Neanderthals, they share two distinct features — the configuration of their semicircular canals and the detailed arrangement of the rear of the skull;

(ii) with late archaic — and early modern — humans across the Old World, they share a large brain size and lightly built cranial vaults with modest brow ridges;

(iii) with earlier (Middle Pleistocene) eastern Eurasian humans, they share a low and broad braincase, one that rounds onto the inferior skull.

“The collective appearance of these features reinforces a pattern of regional population continuity in eastern Eurasia 100,000 years ago, as well as population connections more broadly across the entire Eurasian continent,” the researchers said.

“The mosaic features also highlight the dynamic nature of human evolution leading up to the emergence of modern humans, as we know them today.”

“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 corresponding author Dr. Xiujie Wu, from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China.

“From their fossil record, eastern Asian late archaic humans have been interpreted to resemble their Neanderthal 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 from the Lingjing site that the nature of these eastern Eurasian early Late Pleistocene archaic humans is becoming clear.”

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Zhan-Yang Li et al. 2017. Late Pleistocene archaic human crania from Xuchang, China. Science 355 (6328): 969-972; doi: 10.1126/science.aal2482