Comparative observations on the premolar root and pulp canal configurations of Middle Pleistocene Homo in China.

This work provides new original data, incorporates the latest human fossil discoveries and suggests that analyzing the variation of premolar root structural organization, notably integrating together root/canal form and number, could possibly contribute to taxonomic and phylogenetic assessments. The mid-Middle Pleistocene populations, or "classic" Homo erectus, in our study show closer affinity to Early and Middle Pleistocene hominins in Eurasia, than to East African early Homo, which supports the suggestion that at least some of the Early Pleistocene hominin groups in Eurasia contribute to the later population; on the other hand, it is still difficult to clearly trace the evolutionary fate of those late Middle Pleistocene populations (roughly assigned as archaic Homo sapiens through a craniodental perspective). More comparable materials from the Early to Middle Pleistocene period as well as precise chronological framework is needed to further explore the evolutionary trends of archaic hominins in the Asian continent before the arrival of modern humans.