The Lithic Assemblage of the Khao Ta Plai Archaeological Site (Late Pleistocene-Early Holocene): Variability of the Technical Behaviours of the Hunter-Gatherer Groups in Southern Thailand

Jutinach Bowonsachoti1,4*, Justin Guibert2, Hubert Forestier3, Arnaud Lenoble5, Sirikanya Chantrasri1, Pitakpoom Argaros4, Sarat Chalawsantisakul4, Apirat Chehlao4, Siriporn Sanghiran4, Phattarapong Kaongern4, and Corentin Bochaton1

Traditionally viewed as a uniform cobble-based tradition, the Hoabinhian is now understood as a flexible and diverse lithic system spanning from the Late Upper Pleistocene to the Early Holocene. However, its variability has been poorly investigated, with a limited number of assemblages having been the object of detailed technological analysis. The present study is a detailed study of the lithic assemblage collected at the Khao Ta Plai archaeological site in Southern Thailand, an assemblage presenting unique characteristics allowing for the discussion of the variability of the “Hoabinhian Technocomplex” at the regional scale. Overall, the assemblage reflects a technological system that combines structured shaping strategies with the expedient exploitation of naturally functional blanks, highlighting flexible technological behaviours closely adapted to local raw material resources and blank morphology. It shows affinities with other regional “Hoabinhian” assemblages, particularly through the shared technological strategy of shaping plano-convex or asymmetrical river cobbles to produce lateral choppers, rabots/planes, and wedges. Flaking (debitage) is rare and appears to be mainly associated with a bipolar reduction strategy, especially the split-cobble technique used to produce half-cobbles. At the same time, the assemblage presents distinctive characteristics. An affordance-based strategy is strongly represented, particularly in the selection and use of shale slabs without modification, as their natural edges were already suitable for use. In contrast, typical Hoabinhian tool types – such as unifacial tools (“sumatraliths”) and bifacial tools – are relatively rare. This pattern expands the currently recognized variability of Hoabinhian industries.