toolmaking technique of prehistoric Europe and Africa, characterized by the production of large flakes (flake tool) from a tortoise core (prepared core shaped much like an inverted tortoise shell). Such flakes, seldom further trimmed, were flat on one side, had sharp cutting edges, and are believed to have been used as skinning knives. Sometimes the butts of Levalloisian flakes were trimmed in a way that suggests hafting onto a handle. The Levalloisian technique gradually replaced the Acheulian in much of Europe during the Third Interglacial period and continued into the Fourth Glacial period. In Africa the prepared core technique had a long history of development in association with the Acheulian industry. The Levalloisian technique was often and widely employed for flake production in Mousterian industries (Mousterian industry) in Europe, western Asia, and northern Africa, as well as in other industries (e.g., Stillbay) in sub-Saharan Africa during the late Pleistocene epoch.