Denisovan Identity in Sahul?

Michael C. Westaway1*, Jason Kariwga2, Matthew Leavesley2, Ladislav Nehman3 and Mark Collard4

Recent genomic research, including modern and ancient DNA analyses, indicates the presence of three to four distinct Denisovan lineages, with at least one population likely occupying regions east of the Wallace Line. This has important implications for interpreting the late Pleistocene hominin record in Sahul and Island Southeast Asia with suggestions that Denisovans were present in northern most Sahul. In this study, we re-evaluate morphological evidence from key fossil specimens to investigate whether a phenotypic signature of Denisovan introgression can be identified. Contemporary Papuan and Aboriginal Australian populations retain approximately 4–5% Denisovan ancestry, and recent proposals have suggested that the distinctive morphology of the WLH 50 fossil may reflect such admixture events. The identification of the Harbin cranium as a Denisovan provides a critical comparative framework for reassessing regional fossils using phylogenetic and morphometric approaches. In parallel, we consider the archaeological context of Denisovan-associated material culture. Lithic assemblages attributed to Denisovans are characterized by broadly Middle Palaeolithic technologies, including Levallois and discoidal reduction methods, and tool types such as cores, scrapers, denticulates, burins, and flakes. However, no discrete Denisovan lithic industry has been identified, as these assemblages overlap substantially with those of Neanderthals and early modern humans. Together, these findings highlight the need for integrated analyses combining genomic, morphological, and archaeological data to better understand Denisovan–Homo sapiens interactions and their potential phenotypic expressions in the fossil record.