Redécouverte d’une faune pléistocène dans les remplissages karstiques de Tam Hang au Laos : Premiers résultats

Tam Hang, located in northeastern Laos, in the Hua Pan province, is a reference site not only for its numerous archaeological and human remains, but also for its two faunal assemblages, whose composition suggests different dating in the Pleistocene. Discovered in 1934 by Jacques Fromaget, a new excavation of the site has been undertaken in 2003. During this campaign, at Tam Hang south, 575 isolated teeth of mammals were extracted from a deep layer of calcareous breccia. This assemblage corresponds to that one described by Arambourg and Fromaget [C. Arambourg, J. Fromaget, Le gisement quaternaire de Tam Nang (Chaîne Annamitique septentrionale). Sa stratigraphie et ses faunes, C. R. Acad. Sci. Paris 203 (1938) 793–795.], as characterized by the presence of Ursus premalayanus, and the rarity of Pongo pygmaeus. Systematics and analysis of teeth show that this new assemblage is composed of archaic subspecies, characteristic of the Middle Pleistocene. The faunal composition suggests ecological conditions also found in other Pleistocene sites of the South-East-Asia mainland area. Finally, the analysis of the process of preservation and deposition enables a brief description of the taphonomy specific of karstic systems.