How to interpret informal flakes assemblages? Integrating morphological description, usewear and morphometric analysis gave better understanding of the behaviors of anatomically modern human from Song Terus (Indonesia)

•We described and quantified forms and functions of Song Terus (Java) stone artifacts.•We integrated morphological description, usewear and morphometrics analysis.•Human interest was not directed towards artifacts of specific forms.•A specific form is not related to a specific function and vice versa.•Human looked for specific useable areas possibly associated with areas of prehension. Stone artifacts are the most numerous remains provided by early Holocene sites in Southeast Asia. They are thus of prime importance to understand better human behaviors of this region. However, they are typo-technologically difficult to characterize and consist mainly of informal flakes. This paper presents an innovative approach focusing on form and function to better assess the prehistoric use of stone tools in the region using a sample of flakes from the cave of Song Terus, Java, Indonesia. The integration of morphological description, usewear and morphometric analysis (Elliptical Fourier Analysis) allows a detailed characterization of tool use not possible with other methods. We demonstrate that a specific form of stone flake is not related to a particular function and vice versa. Our results show that tool production was not oriented towards the production of flakes of specific form, or to the production of flake blanks that could be modified by retouch but was a system where the control of flake shape was relaxed in favor of the selection of flakes suitable for particular tasks either during reduction or once core reduction had concluded.