The MIS 4 climatic’s period (approximately 75-60 ka BP) corresponds, in southwestern France, to the gradual replacement of Atlantic forests, sheltering non-migratory temperate fauna (Deer, Roe Deer, Wild boar), by a biotope dominated by the arctic steppe, in which Reindeer would have found a favorable place to live. These environmental disturbances were accompanied by major changes in Neanderthal societies, with the establishment of the Quina Mousterian, a remarkable techno-complex of the end of the Mousterian which saw the emergence of massive and seasonal reindeer slaughter, associated with butchery operations and tool’s production and maintenance now sequenced in time and space. As part of this phD, data from classical archaeozoology and cementochronology are combined and integrated into 3D taphonomic and spatial studies, in order to investigate under high stratigraphic resolution the recording sequences covering the implementation and dissemination of the Quina Mousterian system, and to specify its links with the environmental disturbances of MIS 4, at a time when Reindeer and Red Deer -two species whose current distributions seldom overlap (taiga)- are observed within the same assemblies, one gradually replacing the other. The preliminary examination of the spatial data acquired (taphonomic and taxonomic variables) on two famous sequences from Perigord (Grotte XVI and Roc-de-Marsal) reveals a particular distribution of taxa in cross-section: Red Deer and Reindeer are not found together within the same units, but are in fact superimposed, thereby invalidating the stratigraphic division made during excavations. These first results undoubtedly have palaeoenvironmental implications (and could perhaps reflect the prey avaibility) and show once again the need to call on taphonomic and spatial studies before any reconstruction from archaeological material.