Mandibular Characteristics to Determine Quaternary Proboscideans of Indonesia

Proboscideans (order Proboscidea) are a group of mammals known for theirdistinctive proboscis or trunk. During the Pleistocene Epoch, proboscideansthrived globally, including the Indonesian Archipelago. Most taxonomic determination for proboscidean fossils have primarily relied on molar analysis. Mandible analysis to determine Quaternary proboscidean taxa in Indonesia was still rarely utilized, despite their high potentiality. Therefore, this research aims to identify the diagnostic characters of Quaternary proboscideans found in Indonesia based on their mandibular characteristics. Quantitative morphometrical analysis and qualitative morphological observations were conducted in determining the diagnostic characters of each taxon. Mandible specimens of modern Asian elephant (Elephas maximus) were also used as a comparison to fossil specimens. The values obtained by morphometric measurements were then analyzed using the Principal Component Analysis (PCA) method using PAST 4.12b software. In addition, qualitative morphological characters obtained were described to further support the PCA results. The results showed that the mandibles of each taxon observed have their own distinguishable characteristics, thus it can be used to determine the taxa of Quaternary proboscideans found in Indonesia.