Stage or Sub-Stage: The Contribution of Small Mammals to the Characterization of Middle Pleistocene Local Climate Variation

Abstract

In western Europe, the Middle Pleistocene is marked by Acheulean settlement and their diversification after the MIS 12. The Arago cave recovery of numerous human settlements correlate to MIS 14, 13 and MIS 12 making it an important site for the understanding of the Lower Palaeolithic in Southwestern Europe. It is also an important site for the understanding of palaeoenvironments and palaeobiodiversity as it has yielded rich faunal associations. The faunal associations allow us to observe three climatic stages within this study: two cold ones and a mild one. Small vertebrates, with their abundance and their diversity, are particularly useful for observing these periods, which historically have been correlated to glacial or interglacial stages. If the first cold phase, dated 438 ± 31 ka, is correlated to the Marine Isotopic Stage 12 (MIS 12), the correlation of the following phases to isotopic stages can be discussed. They may correspond to climatic variations of the MIS 12. Indeed, the latest studies about palaeoclimatic reconstitution which allow us to define the evolution of the palaeo-temperature show that these differences are relatively small. Therefore, instead of a correlation to MIS 12, 13 and 14, the medium complex of the Arago cave could belong solely to MIS 12. The correlation of these environmental changes to other global data, notably the isotopic curve, is challenging because there are various local factors influencing faunal association. We propose here both hypotheses and discuss the various factors which influence the distribution and the representation of the small vertebrate species present on the site.