Late pleistocene mammal teeth from the Tham Lod rockshelter, Amphoe Pang Mapha, Changwat Mae Hong Son

Abstract

An enormous mammal teeth discovered in the late Pleistocene archaeological site plays an important evidence identifying to mammalian species which its habitat is fundamental information in reconstructing paleoenvironment. In the late Pleistocene, some regions of the world including the inner part of Southeast Asia e.g. the Tham Lod Rockshelter was also affected by the environment change. The aim of this research is to identify mammalian species and to use mammalian species to reconstructing forest by the morphology and size classification of mammal teeth. As teeth are clear character and well preserved part than other bone, they can be clearly identified to genus and species taxa and applied for paleoenviroment interpretation. Moreover, some dental morphological feature such as size can assist to interpret the paleoenviroment change. This research is focused on paleontological aspect which will help to interpret the paleoenviroment at Tham Lod rockshelter in late Pleistocene epoch. According to the morphology and size classification of mammal teeth from area 1 (S23 W10) in the Tham Lod Rockshelter, Amphoe Pang Mapha, Changwat Mae Hong Son, consist of 8 layers dated during 35,000 to 2,900 BP or late Pleistocene to Holocene, the total amount of the mammal teeth are 2,003 number of identified specimens (NISP) or 218 minimal number of individual (MIN). These can be classified into 31 taxa and divided into 11 families 13 genus 6 species. Most of them are Cervidae, Sus scrofa, Bovinae and Pecora. The palaeoenvironment interpretation from the specialized habitat can be confirmed that the existence of Rhizomyidae, Rhizomys spp., Cannomys badius, Bandicota spp., Bandicota indica, Ursus thibetanus, Bubalus sp., Naemorhedus spp. around 35,000 to 22,000 BP has been observed. These animals indicate the mixed deciduous forest, hill evergreen forest, bamboo forest, lime stone forest, open forest/grass field and swamp. They also existed until 22,000 to10,000 BP. Thus, it can be assumed that the forests was similar from 35,000 to 10,000 BP. Furthermore, Rhinocerotidae was discovered, and it indicates the dense forest. According to these specialized habitat-mammals such as Rhizomyidae, Rhizomys spp., Cannomys badius, Rhinocerotidae etc. indicate that the forest around of Thamlod rockshelter are still the same from late Pleistocene to present. According to the teeth size of Naemorheus spp. dated 35,000 to 22,000 BP in the study area are obviously larger than the teeth found in another period (22,000 to 10,000 BP) including the teeth of recent animals. The cause of changing the size are due to decreasing amount of food, the warmer climate and/or interspecific competition which might be affected by the change of environment in the terminal Pleistocene period.