This is a bifacial scraper from the Quina-Mousterian in the Charente (9 cm long)
We do not know if Neanderthals ever recognized a dichotomy between unifacial and bifacial stone tools. Archaeologists since Lartet and Christy proposed that this dichtomy would be important in recognizing specific “cultures” and their sucessors suggest, that uni-versus bifacial production could still serve as indicators for certain techno- complexes. In this view unifacial and bifacial technologies and tools are often treated as separate entities
From a technological point of view, it has been suggested that the basic operations of tool making are Façonnage and Débitage.
Façonnage is a knapping operation finalized to obtain only one tool shaping a raw material block according the wanted shape. This term is applied to the production of choppers, polyhedrons, bifacially shaped tools whatever is the dimensions of the blanks and of the final products. Generally, the façonnage of a tool is characterized by a preliminary rough phase, followed by a second phase which gives the final shape and it can utilize different techniques. Even if the façonnage can give a lot of flakes and debris, it differentiates itself from the débitage because it is finalized to the transformation of a blank in a tool and not to the production of flakes (Fig. 2: MTA Handaxe from the Beune Valley, Dordogne, France). The product of Façonnage , for example a handaxes, can be the starting point for a new operational sequence, were the handaxe serves as a core.
Débitage is a knapping operation conceived to break the raw material by percussion or pressure in order to obtain flakes and blades which can be subsequently transformed (Fig. 3: unifacial Quina scraper from the Quina Type-site, Charente; France). There are two categories of débitage objects: the cores and the débitage products (flakes, debris, knapping accidents). They are complementary between them. Generally, the main phases of the débitage are represented by the shaping out of the flaked surfaces, the striking platform or the pressure platform, then by an initial débitage phase and a full débitage phase, finally by an eventual exhaustion phase. During these reduction phases new preparations can be necessary to reshape the flaked surfaces.
During the European Middle Paleolithic, a bifacial instrument is usually produced by Façonnage: for example the Prądniks from the Buhlen Site in Germany were made from Lydite pebbles by Façonnage. The flat MTA handaxes of France were usually made from larger flakes by the same principle.
Anyhow, typologically bifacial tools have sometimes a use-life that is technologically much more complex. M. Kot (Quaternary International 428 (2017) recently showed that most of the bifacial tools from the Ehringsdorf site near Weimar / Germany (MIS7) were initially made as unifacial side scrapers. During subsequent phases of modification the tools were sometimes reworked on both edges and after several phases of rejuvenation, the tools became fully bifacially worked „Blattspitzen“.
In this case, bifacial treatment of initial unifacial tools seem to have been the flexible response of Neanderthals to prolong the use-life of initial unifacial artifacts.