Trophic ecology of a Late Pleistocene early modern human from tropical Southeast Asia inferred from zinc isotopes

Tam Pa Ling, a cave site in northeastern Laos, has yielded the earliest skeletal evidence of Homo sapiens in mainland Southeast Asia. The reliance of Pleistocene humans in rainforest settings on plant or animal resources is still largely unstudied, mainly due to poor collagen preservation in fossils from tropical environments precluding stable nitrogen isotope analysis, the classical trophic level proxy. However, isotopic ratios of zinc (Zn) in bioapatite constitute a promising proxy to infer trophic and dietary information from fossil vertebrates, even under adverse tropical taphonomic conditions. Here, we analyzed the zinc isotope composition (Zn-66/Zn-64 expressed as delta Zn-66 value) in the enamel of two teeth of the Late Pleistocene (63-46 ka) H. sapiens individual (TPL1) from Tam Pa Ling, as well as 76 mammal teeth from the same site and the nearby Nam Lot cave. The human individual exhibits relatively low enamel delta(66Z)n values (+0.24 parts per thousand) consistent with an omnivorous diet, suggesting a dietary reliance on both plant and

Automated summary

The cave site of Tam Pa Ling in northeastern Laos has provided the earliest skeletal evidence of Homo sapiens in mainland Southeast Asia. Analysis of zinc isotope composition in the enamel of teeth from both humans and other mammals from the site suggests an omnivorous dietary reliance on plant and animal resources.