A New Human Humeral Fossil From the Early Holocene in Northeast China

This study aims to provide new insights into the morphological, biomechanical, and ecological adaptations of early modern humans in Northeast China through an integrated analysis of an Early Holocene humerus from Heilongjiang Province. A multidisciplinary approach is employed to assess the humeral structural and functional characteristics and to infer aspects of the individual's subsistence strategy.

The partial humerus (specimen 23HLJ-H-Hm03) was analyzed using traditional osteometric measurements, computed tomography-based analysis of cross-sectional geometry, morphometric mapping of cortical bone thickness and second moments of area, and stable carbon and nitrogen isotope analysis.

The Heilongjiang humerus exhibits a relatively robust midshaft structure comparable to that of contemporary human fossils, along with diaphyseal and epiphyseal morphology features of anatomically modern humans. Morphometric mapping reveals diaphyseal reinforcement patterns aligned with those of other East Asian Upper Paleolithic humans, though the overall magnitude of reinforcement falls within the upper range of Late Upper Paleolithic modern human variation. Stable isotope values (δ¹³C and δ¹⁵N) indicate a predominantly C₃-based diet derived mainly from terrestrial herbivores.

The Heilongjiang humerus exhibits morphological affinities with Late Upper Paleolithic modern humans. Its relatively greater robusticity, coupled with isotopic evidence, supports the inference of a physically demanding hunter-gatherer lifestyle. This study enhances our understanding of modern human variation in East Asia during the Late Upper Paleolithic and offers preliminary insights into the biological and behavioral transitions across the Pleistocene-Holocene boundary in Northeastern Asia.