... These early Acheulean tools, often characterised by handaxes and cleavers, are typically thought to have been produced using hard-hammer percussion. Bifaces go on to typify the next >1 million years of the archaeological record across the Old World (Lycett & Gowlett, 2008;Gowlett, 2015;Moncel et al., 2015) until the onset of Middle Palaeolithic technologies ∼300 Kya (Moncel et al., 2011;Tryon & Faith, 2013;Adler et al., 2014). The nature and extent of any chronological changes to stone technology during the Acheulean are debated (e.g., Vaughan, 2001;Chauhan, 2009;Gowlett, 2011;McNabb & Cole, 2015;Moncel et al., 2015;Gallotti, 2016), however, there are indications that later Acheulean bifacial tools (handaxes in particular) were at times produced using soft-hammer percussion, became thinner relative to their width (more 'refined'), displayed greater evidence of intentional thinning, volume control (mass distribution), investment (e.g., time, skill), shaping and symmetry (Gowlett, 1986;Saragusti et al., 1998;Schick & Clark, 2003;Grosman, Goldsmith & Smilansky, 2011;Beyene et al., 2012;García-Medrano et al., 2014;Li et al., 2018;Moncel et al., 2016;Gallotti & Mussi, 2017;Iovita et al., 2017;Shimelmitz et al., 2017), and at times displayed evidence of platform preparation prior to a flake's removal (Stout et al., 2014). ...