The world's earliest ground stone needles: Archaeological evidence from the early Holocene of the Western Tibetan Plateau

The earliest grinding and perforating techniques used for manufacturing bone tools represent an important aspect of the complexity of modern human behaviors. Ground perforated stone tools appeared relatively later, mainly as small ornaments and portable tools, and have been discovered extensively within the context of Neolithic technological complexity. We present six ground stone perforated (eyed) needles dated to the early Holocene from the Xiada Co (XDC) site. They represent the earliest known stone ground needles in Eurasian archaeological context, as well as the earliest instance of ground stone artefacts found on the Tibetan Plateau. We employed a combination of microscopic analysis, experiments, three-dimensional (3D) models, and residue analysis in conjunction with previous ethnographic studies to analyze the needles' production processes, and potential functions. The findings indicated that modern humans of the Tibetan Plateau possess technological skills in ground technology and intentionally selected appropriate raw materials for processing stone needles at 8,900–8,500 cal. BP. We found that the production of stone needles involves the selection of blanks, scrapping, grinding and drilling, which is more time-consuming than producing bone needles. However, stone needles are harder and better suited for sewing tents. Our analysis of stone needles suggests they represent a special adaptive behavior of modern humans after their spread to and the permanent settlement of the Tibetan Plateau, which has not yet been found elsewhere. Furthermore, the discovery of pigments on stone needles indicates their possible ornamental functions, which could be one of the earliest instances of symbolism on the Tibetan Plateau.