Exploring the diversity of fossil hominin dental patterns in the western Indonesian archipelago during the Quaternary by Geometric Morphometric Analysis. Application on second upper and lower molars

Islands of the western part of the Indonesian archipelago were impacted by climatic and sea level changes during Pleistocene, which affected the dispersals and/or isolation of hominins in this region. This study aims to characterize the diversity of ancient human populations in the Sundaland based on dental collections from several localities in Sumatra and Java. The material consists of 111 teeth, 57 from Pleistocene hominins and 54 from Holocene Homo sapiens. The study of external morphology was done by geometric morphometric analysis on the occlusal surface of the upper (N=47) and lower second molars (N=64). We observe group clustering among the samples. There are at least four groups (dental types) of hominins during Pleistocene times. Result suggest that there is an overlapping among them throughout the Lower and early Middle Pleistocene; another group persists until the Late Pleistocene, and two other groups of H. sapiens are present during the Holocene. The implication of this study sheds light on the history of ancient human occupation (continuity/rupture) in Island Southeast Asia during the Quaternary period.