The phylogenetic position of the Yunxian cranium elucidates the origin of Dragon Man and the Denisovans

Abstract

Diverse Middle Pleistocene forms of Homo coexisted in Africa, Europe, and Asia. It is very controversial whether these fossil humans represent different species or lineages. The ~1 Ma old Yunxian 2 fossil from China is crucial for understanding the cladogenesis ofHomoand the origin ofHomo sapiens. Here, we restored and reconstructed the distorted Yunxian 2 cranium using new technology. The results show that this cranium displays mosaic features of plesiomorphy and apomorphy. Phylogenetic analyses and Bayesian tip-dating including the reconstructed Yunxian 2 suggest that it is an early member of the Asian 'Dragon Man' lineage, which probably includes the Denisovans, and is the sister group of theH. sapienslineage. Both theH. sapiensand Dragon Man lineages had deep roots extending beyond the Middle Pleistocene, and the basal position of the Yunxian fossil cranium suggests it represents a population lying close to the last common ancestor of the two lineages.