Proc Natl Acad Sci U S A 2012 Sep 21;109(36):14500-3. Epub 2012 Aug 21.
International Graduate Center of Evolution, Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel.
Using direct percussion, language-competent bonobo-chimpanzees Kanzi and Pan-Banisha produced a significantly wider variety of flint tool types than hitherto reported, and used them task-specifically to break wooden logs or to dig underground for food retrieval. For log breaking, small flakes were rotated drill-like or used as scrapers, whereas thick cortical flakes were used as axes or wedges, leaving consistent wear patterns along the glued slits, the weakest areas of the log. For digging underground, a variety of modified stone tools, as well as unmodified flint nodules, were used as shovels. Read More