Raspadita: a new lithic tool from the Isthmus of Rivas,Nicaragua

A new lithic tool type was discovered at the Pacific Nicaraguan archaeological site of Santa Isabel (AD 800–1350) and named raspadita (small scraper). Thousands of these small tools (1–2 cm in length) were found. They have a rounded proximal edge and a pointed distal end. In this study, the raspaditas are proved to be a coherent tool class with minimal variation in size, shape, material type and usewear. They were manufactured from white chert bladelet cores using soft hammer percussion and pressure flaking unifacial retouch. Usewear points to a composite tool form and a scraping function for the raspaditas. Scanning electron microscopy determined a ventral leading, dorsal following, unidirectional scraping motion for the raspadita proximal end. The material that was scraped has still to be definitely determined but phytoliths visible in the SEM images suggest that the composite tool was used for plant processing.     

Early and mid Holocene tool-use and processing of taro (Colocasia esculenta), yam (Dioscorea sp.) and other plants at Kuk Swamp in the highlands of Papua New Guinea

Recent multidisciplinary investigations document an independent emergence of agriculture at Kuk Swamp in the highlands of Papua New Guinea. In this paper we report preliminary usewear analysis and details of prehistoric use of stone tools for processing starchy food and other plants at Kuk Swamp. Morphological diagnostics for starch granules are reported for two potentially significant economic species, taro (Colocasia esculenta) and yam (Dioscorea sp.), following comparisons between prehistoric and botanical reference specimens. Usewear and residue analyses of starch granules indicate that both these species were processed on the wetland margin during the early and mid Holocene. We argue that processing of taro and yam commences by at least 10,200 calibrated years before present (cal BP), although the taro and yam starch granules do not permit us to distinguish between wild or cultivated forms. From at least 6950 to 6440 cal BP the processing of taro, yam and other plants indicates that they are likely to have been integrated into cultivation practices on the wetland edge.     

Identifying expedient glass tools from a post-contact Tsimshian village using low power (10–100×) magnification

Glass shards from post-contact contexts at the Northern Tsimshian site of Ginakangeek, on the north coast of British Columbia Canada, are identifiable as expedient tool artifacts through analysis of usewear patterns. In this study, we have examined the nature of glass and argued that its mineralogical properties make it analogous to other lithic materials. Although other researchers have found evidence of a lithic-like industry of glass artifacts based on macroscopic features, we have demonstrated that expedient artifacts are identifiable even in the absence of macroscopic traits, through low-power magnification of usewear. We have also tested this thesis against the possibility that microscopic usewear-like patterns were the product of fragmentation or post-depositional effects, and argued that a suite of usewear traits correlates only with use activity. Our experimental suite of glass artifacts indicates that specific actions (such as cutting, scraping, sawing, and chiseling) and the relative hardness of specific substrates produce particular usewear patterns. A number of potential explanations are considered for the appearance of such an industry on the Northwest Coast more than a century after contact with Europeans.     

A functional analysis of grinding stones from an early holocene site at Donghulin,North China

The processes that led to the transition from small mobile groups of hunter-gatherers in the Late Pleistocene to sedentary communities of the Early Holocene in north China are poorly understood. The Donghulin site in Beijing was occupied at the onset of the Holocene, and excavations have revealed a rich archaeological record for investigating the changing subsistence strategies during this transitional period. A functional study of two grinding stones (a slab and a handstone) near a burial dated to 9220–8750 cal BC at Donghulin investigated the range of plants exploited during this early occupation period. Starch residues indicate that the grinding stones were used for processing plants, and confirm processing of acorns, which is consistent with the incidence of oak in the pollen record. The usewear, with only rare patches of developed polish, suggests that plant parts of low silica content were processed, although usewear on the handstone suggests processing of two or more plant taxa. The results suggest that the use of grinding stones to process plant foodstuffs, particularly acorns, may have played a major role in the subsistence strategy during the transitional period to sedentism and agriculture in some parts of north China.