The Cave of the Monk (Ban Fa Suai, Chiang Dao wildlife sanctuary, northern Thailand)

Biostratigraphic and paleoecological analyses of Southeast Asian Pleistocene faunal sites are based on the assumption that paleontological assemblages are homogeneous. This means that the sites formed during a time range shorter than biological evolution range and, above all, without faunal replacement induced by environmental successions. Detailed study of the Cave of the Monk paleontological site, in Thailand, has lead to the conclusion that the complex pattern of this Southeast Asian paleontological site cannot support such an assumption.The Cave of the Monk provides an Ailuropoda–Stegodon assemblage typical of Southeast Asia Pleistocene Fauna. The pluridisciplinary study presented here includes (i) site morphology description, (ii) sedimentological analysis of fossiliferous deposits, (iii) taphonomy study of the bone assemblage, and (iv) electron spin resonance (ESR) dating of tooth samples. This integrated approach demonstrates the existence of a Pleistocene porcupine den inhabited during MIS 3 and 2. The features of this site are commonly reported for other paleontological sites of the area, indicating that this kind of site formation is a very general one in Southeast Asia.ESR dating and porcupine ethological reports are used to question the site time averaging. A time range of a few tens of thousands of years is suggested. The paleoecological value of the site can then be discussed. On one hand, the assemblage is thought to be a valuable paleoenvironmental record considering that the bone accumulation agent is reputed to represent the fauna present in the environment without bias. On the other hand, the time averaging of the site indicates that site formation range likely covered the environmental fluctuations of the last climatic cycle. This last hypothesis is confirmed by the alternating association of species indicated by the stratigraphic distribution of the faunal remains.The research demonstrates the need for integrated and pluridisciplinary taphonomic study of Southeast Asian paleontological sites. It also reveals the utility of a microstratigraphic analysis of a fossiliferous karst deposit in order to disentangle the succession of Pleistocene mammals in response to environmental changes.