Les faunes de grands mammifères de la Caune de l'Arago (Tautavel) dans le cadre biochronologique des faunes du Pléistocène moyen italien

Abstract

The fossiliferous levels of Caune de l'Arago supply a useful tool to investigate the relationships between faunal renewals and climate changes in a restricted area during the Middle Pleistocene. On the other hand the Italian fossil assemblages of the middle Galerian testified changes of palaeoenvironmental conditions. A biochronologic and palaeoecologic comparison among large mammalian faunas of these quite different Mediterranean regions have been performed in the aim to value possible vicariance of taxa and differences of faunal renewal dynamic during the Middle Pleistocene. After the results of our analysis we can correlate the faunal assemblages from the “Complexe moyen, ensemble stratigraphique I”, “Complexe moyen, ensembles stratigraphiques II and III”, “Complexe supérieur, sols A and B” of Caune de L'Arago sedimentary succession with the Italian Isernia (middle Galerian), Fontana Ranuccio (late Galerian) and Torre in Pietra (early Aurelian) faunal units (FUs) respectively. The French faunal assemblages were characterised by the absence of browsers and, conversely, by the presence of boreal taxa, mainly grazers, that were rare or never occurred in Italy. Accordingly, at no one Italian faunal complex, as expected, we can find any indication of continental cold climatic condition as showed by the faunal complexes of the Caune de l'Arago. Nevertheless, the major climate changes characterising the Middle Pleistocene can be detected in both regions. During the span time of Isernia FU, the temperature was at its lowest and arid conditions prevailed, whereas during the following Fontana Ranuccio FU humidity and temperature increased, as is more evident in central Italy local faunas. Moreover, after the similarity analysis, the Visogliano local fauna (North-Eastern Italy) was more related to the French than to the Italian ones. During the late Middle Pleistocene (Torre in Pietra FU) a moderate faunal reconstruction can be detected in both regions. The renewal was linked to climatic modifications taking place in the Mediterranean area approximately around OIS 11/OIS 10 transition, when interstadials became progressively milder and average humidity increased.