ABSTRACT
The interest in the development of dental enamel thickness measurement techniques is connected to the importance of metric data in taxonomic assessments and evolutionary research as well as in other directions of dental studies. At the same time, advances in non-destructive imaging techniques and the application of scanning methods, such as micro-focus-computed X-ray tomography, has enabled researchers to study the internal morpho-histological layers of teeth with a greater degree of accuracy and detail. These tendencies have contributed to changes in established views in different areas of dental research, ranging from the interpretation of morphology to metric assessments. In fact, a significant amount of data have been obtained using traditional metric techniques, which now should be critically reassessed using current technologies and methodologies. Hence, we propose new approaches for measuring dental enamel thickness using palaeontological material from the territories of northern Vietnam by means of automated and manually operated techniques. We also discuss method improvements, taking into account their relevance for dental morphology and occlusion. As we have shown, our approaches demonstrate the potential to form closer links between the metric data and dental morphology and provide the possibility for objective and replicable studies on dental enamel thickness through the application of automated techniques. These features are likely to be effective in more profound taxonomic research and for the development of metric and analytical systems. Our technique provides scope for its targeted application in clinical methods, which could help to reveal functional changes in the masticatory system. However, this will likely require improvements in clinically applicable imaging techniques.
ABSTRACT
An integrative taxonomic analysis delimits and diagnoses the new species Hemiphyllodactylus cattien sp. nov. from Cat Tien National Park, Dong Nai Province, southern Vietnam-the eighth species of Hemiphyllodactylus to be described from Vietnam. The new species is recovered as the sister species to a clade comprised of H. indosobrinus from Laos and H. flaviventris from Thailand based on phylogenetic analyses using ND2 mtDNA gene sequences. Unlike the vast majority of Hemiphyllodactylus which are site-restricted upland endemics, Hemiphyllodactylus cattien sp. nov. is a lowland species collected from one of the most well-surveyed regions in Vietnam. Its discovery further emphasizes the need for continued re-sampling of survey sites already considered to be well-explored.
Subject(s)
Forests , Lizards , Animals , Phylogeny , VietnamABSTRACT
The dental remains of Gigantopithecus blacki von Koenigswald, 1935 (a complete right m2 with roots and distal fragment of left m2 crown) from the Upper Pleistocene deposits of the Lang Trang cave in northern Vietnam (Thanh Hoa Province) are described. It is the first record of Gigantopithecus in the Upper Pleistocene of Vietnam and, apparently, the second one in the Upper Pleistocene in general (considering material from Shuangtan cave in southern China). Probably, the extinction of G. blacki was confined to the Middle-Late Pleistocene transition, and the specimens from the Lang Trang cave belong to one of the latest relict populations of Gigantopithecus.
Subject(s)
Hominidae , Tooth , Animals , China , Fossils , VietnamABSTRACT
The following mammal assemblage was identified among the materials collected in 2020 from the Pleistocene of the Lang Trang cave (northern Vietnam): the primates Pongo sp., Trachypithecus sp., Macaca cf. nemestrina (Linnaeus, 1766), and Macaca sp.; the carnivorans Arctonyx collaris rostratus Matthew et Granger, 1923 and Panthera sp.; the chiropteran Ia io Thomas, 1902; the rodent Hystrix kiangsenensis Wang, 1931; the proboscidean Elephas sp.; the perissodactyls Tapirus indicus (Desmarest, 1819) and Dicerorhinus sumatrensis (Fischer, 1814); the artiodactyls Sus scrofa Linnaeus, 1758, S. barbatus Müller, 1838, Tragulus kanchil (Raffles, 1821), Hydropotes inermis Swinhoe, 1870, Muntiacus muntjak (Zimmermann, 1780), Axis porcinus (Zimmermann, 1780), Rusa unicolor (Kerr, 1792), and Capricornis sumatraensis (Bechstein, 1799). I. io, S. barbatus, T. kanchil, H. inermis, and A. porcinus were detected in the Lang Trang fauna for the first time. The mammal assemblage is dominated by inhabitants of tropical forests (from lowlands to mountains), subtropical forms are also present.
