Human remains from Zhirendong, South China, and modern human emergence in East Asia.

The 2007 discovery of fragmentary human remains (two molars and an anterior mandible) at Zhirendong (Zhiren Cave) in South China provides insight in the processes involved in the establishment of modern humans in eastern Eurasia. The human remains are securely dated by U-series on overlying flowstones and a rich associated faunal sample to the initial Late Pleistocene, >100 kya. As such, they are the oldest modern human fossils in East Asia and predate by >60,000 y the oldest previously known modern human remains in the region. The Zhiren 3 mandible in particular presents derived modern human anterior symphyseal morphology, with a projecting tuber symphyseos, distinct mental fossae, modest lateral tubercles, and a vertical symphysis; it is separate from any known late archaic human mandible. However, it also exhibits a lingual symphyseal morphology and corpus robustness that place it close to later Pleistocene archaic humans. The age and morphology of the Zhiren Cave human remains support a modern human emergence scenario for East Asia involving dispersal with assimilation or populational continuity with gene flow. It also places the Late Pleistocene Asian emergence of modern humans in a pre-Upper Paleolithic context and raises issues concerning the long-term Late Pleistocene coexistence of late archaic and early modern humans across Eurasia.

Dentoalveolar paleopathology of the early modern humans from Zhirendong, South China.

The fragmentary early Late Pleistocene, early modern human remains from Zhirendong, south China, present a suite of dentoalveolar pathologies and anomalies. The lesions include lower molar buccal alveolar resorption (Zhiren 1), massive dental caries in a mandibular molar associated with hypercementosis (Zhiren 2), and bilateral mesial premolar (P3) periapical lesions (granulomata with a probable left abscess) (Zhiren 3). The Zhiren 3 periapical lesions, given their bilaterality and the non-pathological incisor and canine alveoli, suggest dens evaginatus, although absence of the Zhiren 3 dentition prevents full evaluation of this diagnosis. These periodontal abnormalities join a number of similar lesions in Pleistocene humans, of varying severity. The carious lesion is noteworthy, given the rarity of them in the Pleistocene human fossil record. In addition, Zhiren 3 exhibits unilateral P3 rotation and bilateral I1 rotation (winging).