Fig 1.
Experimental tools used to produce retouch flakes.
A) Tool 14 used to scrape a cattle femur, B) Tool 7 used to harvest nettles, C) Tool 9 used to scrape fibres from nettle stems, D) Tool 4 used to scrape fresh hide.
Table 1.
The tool type, contact material, directionality, type of preparation, retouching hammer type and duration of the experiments used to produce resharpening flakes.
Fig 2.
Wear traces on the blind test retouch flakes.
A) Flake 23 from a tool used to harvest nettle, B) Flake 20 from a tool used to scrape hazel bark and wood, C) Flake 32 from a tool used to scrape lime bark, D) Flake 2 from a tool used to scrape fresh hide, E) Flake 17 from a tool used to groove bone, F) Flake 21 from a tool used to scrape pine. All images at 200x. Photos A, B, C, D and F show the external platform edge of the butts of retouch flakes, the surface that was originally the ventral side of the use-edge of the parent tool. Photo E shows wear on a dorsal ridge of the retouch flake, which was originally the ridge between two retouch facets on the retouched dorsal side of the use-edge of the parent tool.
Table 2.
The sample of retouch flakes used for the blind test (species names of contact materials are provided in Table 1).
Table 3.
The attributes and attribute states the blind testers were asked to record on the sample of retouch flakes.
Table 4.
The responses and correctness of responses of Blind Tester 1.
Table 5.
The responses and correctness of Blind Tester 2.
Table 6.
The responses and correctness of Blind Tester 3.
Fig 3.
Jitter plots for each blind tester showing the dispersion of correct and incorrect responses to the used/unused attribute according to flake weight (g).
Blind Tester number indicated in top left hand corner of each plot.
Fig 4.
Logistic regression plots for each blind tester showing the relationship between flake weight and correct and incorrect responses.
Blind Tester number indicated in top left hand corner of each plot.
Fig 5.
The correctness of responses to the used/unused attribute.
Fig 6.
The correctness of responses to the directionality attribute.
See Table 3 for a description of attribute states.
Fig 7.
The correctness of responses split by the directionality of use of retouch flakes.
See Table 3 for a description of attribute states.
Fig 8.
The correctness of identifications of general categories of contact material.
Fig 9.
The correctness of identifications of specific categories of contact material.
Fig 10.
The correctness of identifications for all blind testers split by contact materials.
Fig 11.
The correctness of identifications for Blind Testers 1 and 3 split by contact materials.
Table 7.
Cross tabulation of the correctness of response for directionality with general categories of contact material.
Table 8.
Cross tabulation comparing the directionality of tool use with the correctness of blind tester responses to identifying directionality on retouch flakes from tools used to work bone and plants.
Fig 12.
The external platform edge of the butt of Flake 32, a retouch flake removed using a stone hammer from a tool used to scrape lime bark.
The diffuse polish near the edge flake is related to the working of the bark, the isolated streaks of flat bright polish associated with linear stria are marks left by the hammer (200x).
Fig 13.
The butt of Flake 18, removed from a tool used to scrape dry hide.
The external platform edge is on the upper side of the butt (100x).
Fig 14.
Comparison of the percentage of correct responses to the identification of different contact materials between all previous studies (APS) taken from Evans [1 Table 3] and this study (TS).
Fig 15.
The butt of Flake 2, a retouch flake removed from a tool used to scrape fresh hide (12.5x).
The external platform edge of the flake is on the lower edge of the butt. The part of the butt formed by the remnant of the original use-edge of the tool where wear traces are surviving is demarcated in red. The part of the butt where the use-edge has been removed by a previous retouch flake removal is demarcated in blue. The red box denotes the location of micrograph D in Fig 2.