In Western Europe, the transition from the middle Iron Age to theearly Roman period implied changesin livestock practices, withthe emergence of a specialized and selective animal husbandry. These changes have been related in Italy and south of France withchanges in livestock management involving their mobility between ecologically complementary areas. The study of this question inthe Iberian Peninsula has only been partiallyinvestigated through palaeoenvironmental analyses, and the information about theorigin and significance of this phenomenon is very scarce. To shed new light on this topic we used an archaeozoological approach,with the application of geometric morphometrics. They were used to study size and shape variability in sheep astragali from 9 sitesdating from the middle Iron Age to the early Roman period (5th c. BC–3rd c. AD) and located on the Pyrenees and on the north-eastern Iberian coast as a case study. The results we obtained, combined with Number of Identified Specimens (NISP) and kill-offpatterns, showed local specificities in terms of breeding methodsand sheep morphologies between the two areas during the middleIron Age. On the contrary, sheep with similar size and the implementation and development of similar sheep husbandry practices inthe Pyrenees and the north-eastern Iberian coast were documented during the early Roman period. These results suggest theexistence of livestock links between these two areas during the Roman period, that could be involved a possible movement ofsheep between the lowlands and the Pyrenees for the first time