Towards an understanding of retouch flakes: A use-wear blind test on knapped stone microdebitage.

The retouching and resharpening of lithic tools during their production and maintenance leads to the production of large numbers of small flakes and chips known as microdebitage. Standard analytical approaches to this material involves the mapping of microartefact densities to identify activity areas, and the creation of techno-typologies to characterise the form of retouch flakes from different types of tools. Whilst use-wear analysis is a common approach to the analysis of tools, it has been applied much less commonly to microdebitage. This paper contends that the use-wear analysis of microdebitage holds great potential for identifying activity areas on archaeological sites, representing a relatively unexplored analytical resource within microartefact assemblages. In order to test the range of factors that affect the identification of use-wear traces on small retouch flakes, a blind test consisting of 40 retouch flakes was conducted. The results show that wear traces can be identified with comparable levels of accuracy to those reported for historic blind tests of standard lithic tools suggesting that the use-wear analysis of retouch flakes can be a useful analytical tool in understanding site function, and in increasing sample sizes in cases where assemblages contain few tools.

Communication during copulation in the sex-role reversed wolf spider Allocosa brasiliensis: Female shakes for soliciting new ejaculations?

Traditional studies on sexual communication have focused on the exchange of signals during courtship. However, communication between the sexes can also occur during or after copulation. Allocosa brasiliensis is a wolf spider that shows a reversal in typical sex roles and of the usual sexual size dimorphism expected for spiders. Females are smaller than males and they are the roving sex that initiates courtship. Occasional previous observations suggested that females performed body shaking behaviors during copulation. Our objective was to analyze if female body shaking is associated with male copulatory behavior in A. brasiliensis, and determine if this female behavior has a communicatory function in this species. For that purpose, we performed fine-scaled analysis of fifteen copulations under laboratory conditions. We video-recorded all the trials and looked for associations between female and male copulatory behaviors. The significant difference between the time before and after female shaking, in favor of the subsequent ejaculation is analyzed. We discuss if shaking could be acting as a signal to accelerate and motivate palpal insertion and ejaculation, and/or inhibiting male cannibalistic tendencies in this species.