Extended Data Fig. 8: Chop marks on ‘cut log’, BLB4 (Fig. 2d).

Upper image shows all views of the object and ___location of modifications (white arrows) on the ends, ‘a’ and ‘b’, two marks on the underlying surface and the preservation of bark on both surfaces. Image below is ‘a’ with its distinctive stepped chop marks (black arrows), and underlying grey image (denatured RTI) shows the width of the step between the first and second chop-mark expanding, left to right, from 13 to 25 mm. The deep, slightly convex cut of the first chop is visible. The underly step expands left to right from 6 mm to 11 mm. A third step starts with a width of 7 mm. Bottom image is end ‘b’ with black arrows indicating ___location of chop marks.