The motifs, techniques and stylistic features of Upper Palaeolithic art offer enormous potential for the investigation of social and cultural interactions in south-western France and northern Spain during the later stages of the last ice age. The key regions of Aquitaine, Cantabria and the Pyrenees clearly share an overall family resemblance, but detailed analysis of horse heads on portable objects of bone, antler and stone from Magdalenian contexts reveal that particular features can be attributed to different regions at different periods. Furthermore, the patterns of interconnection are structured very differently in the Upper Magdalenian than in the Middle Magdalenian, perhaps as rising temperatures in the latter period led to territorial expansion and social realignment.