Mandibular Characteristics to Determine Quaternary Proboscideans of Indonesia

Arkanniti Dibyawedha  Adisajjana; Donan Satria  Yudha

doi:10.22146/jtbb.16665

Arkanniti Dibyawedha Adisajjana Faculty of Biology, Universitas Gadjah Mada. Jl. Teknika Selatan, Sinduadi, Mlati, Sleman, Yogyakarta 55281, Indonesia https://orcid.org/0009-0006-4833-9857
Donan Satria Yudha Faculty of Biology, Universitas Gadjah Mada. Jl. Teknika Selatan, Sinduadi, Mlati, Sleman, Yogyakarta 55281, Indonesia https://orcid.org/0000-0003-4758-3314

DOI: https://doi.org/10.22146/jtbb.16665

Keywords: Fossil, Identification, Indonesia, Mandible, Proboscidea, Quaternary

Abstract

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.

References

Carlton, R.L., 2019. A Concise Dictionary of Paleontology: Second Edition, Cham: Springer International Publishing. doi: 10.1007/978-3-030-25586-2.

Feldhamer, G.A., 2020. Mammalogy: Adaptation, Diversity, Ecology Fifth edition., Baltimore: Johns Hopkins University Press.

Ferretti, M.P. & Debruyne, R., 2011. Anatomy and phylogenetic value of the mandibular and coronoid canals and their associated foramina in proboscideans (Mammalia). Zoological Journal of the Linnean Society, 161(2), pp.391–413. doi: 10.1111/j.1096-3642.2010.00637.x.

Hammond, N.L., Dickman, A. & Biggs, D., 2022. Examining attention given to threats to elephant conservation on social media. Conservation Science and Practice, 4(10), e12785. doi: 10.1111/csp2.12785.

Lee, P.C. et al., 2011. African elephant age determination from teeth: validation from known individuals. African Journal of Ecology, 50(1), pp.9–20. doi: 10.1111/j.1365-2028.2011.01286.x.

Li, C. et al., 2023. Longer mandible or nose? Co-evolution of feeding organs in early elephantiforms. eLife, 12, RP90908. doi: 10.7554/eLife.90908.1.

Meijer, H.J.M. et al., 2010. The fellowship of the hobbit: the fauna surrounding Homo floresiensis. Journal of Biogeography, 37(6), pp.995–1006. doi: 10.1111/j.1365-2699.2010.02308.x.

Prothero, D.R. & Williams, M.P., 2017. The Princeton Field Guide to Prehistoric Mammals, Princeton, New Jersey: Princeton University Press.

Riddle, H.S. et al., 2010. Elephants - a conservation overview. Journal of Threatened Taxa, 2(1), pp.653–661. doi: 10.11609/JoTT.o2024.653-61.

Setiyabudi, E., 2016. Pleistocene Reptiles of The Soa Basin (Flores, Indonesia): Adaptation and Implication for Environment. Jurnal Geologi dan Sumberdaya Mineral, 17(2). doi: 10.33332/jgsm.geologi.v17i2.23.

Sharma, R. et al., 2018. Genetic analyses favour an ancient and natural origin of elephants on Borneo. Scientific Reports, 8(1), 880. doi: 10.1038/s41598-017-17042-5.

Sukmasuang, R. et al., 2024. Review: Status of wild elephant, conflict and conservation actions in Thailand. Biodiversitas, 25(4), pp.1479-1498. doi: 10.13057/biodiv/d250416.

Sukumar, R., 2003. The Living Elephants: Evolutionary Ecology, Behavior, and Conservation, New York: Oxford University Press.

Todd, N.E., 2010. Qualitative Comparison of the Cranio‐Dental Osteology of the Extant Elephants, Elephas Maximus (Asian Elephant) and Loxodonta africana (African Elephant). The Anatomical Record, 293(1), pp.62–73. doi: 10.1002/ar.21011.

van den Bergh, G.D., 1999. The Late Neogene elephantoid-bearing faunas of Indonesia and their palaeozoogeographic implications. Scripta Geologica, 117, pp.1–419.

van den Bergh, G.D., de Vos, J. & Sondaar, P.Y., 2001. The Late Quaternary palaeogeography of mammal evolution in the Indonesian Archipelago. Palaeogeography, Palaeoclimatology, Palaeoecology, 171(3–4), pp.385–408. doi: 10.1016/S0031-0182(01)00255-3.

van den Bergh, G.D. et al., 2008. The youngest stegodon remains in Southeast Asia from the Late Pleistocene archaeological site Liang Bua, Flores, Indonesia. Quaternary International, 182(1), pp.16–48. doi: 10.1016/j.quaint.2007.02.001.

von Koenigswald, W., 2016. The diversity of mastication patterns in Neogene and Quaternary proboscideans. Palaeontographica Abteilung A, 307(1–6), pp.1–41. doi: 10.1127/pala/307/2016/1.

Wibowo, U.P. et al., 2015. Indonesian Archipelago Paleogeography as the Natural Laboratory of the Proboscidean Migration and Adaptation Pattern. Proceedings Joint Convention Balikpapan.

Zhang, H. et al., 2017. An examination of feeding ecology in Pleistocene proboscideans from southern China (Sinomastodon, Stegodon, Elephas), by means of dental microwear texture analysis. Quaternary International, 445, pp.60–70. doi: 10.1016/j.quaint.2016.07.011.