Diversity and paleoecology of Greek late Miocene mammalian faunas

Abstract

The late Miocene of Macedonia has yielded several rich faunal assemblages, ranging from late Vallesian to late Turolian. They may be compared to the classical localities of Pikermi, Samos and Maragheh. Taxonomic comparisons based upon updated faunal lists allowed us to compute faunal similarity indices, which were submitted to principal component and cluster analysis. On the graphs, “Ravin de la Pluie” is always remote from the other Macedonian fossil mammal localities: it can only be explained by its Vallesian age. The other Macedonian sites cluster next, demonstrating some provinciality of this area during the Turolian. Comparisons of the frequencies of the various taxonomic groups support the installation of a more forested environment in the latest faunal set, Dytiko. The indices of diversity and the rank-abundance curves seem also to reflect a change of the ecological conditions during the Turolian: the fauna of “Ravin de la Pluie” and of the Vathylakkos-Prochoma-“Ravin des Zouaves” group is marked by the predominance of 1 or 2 species, while the species frequency of the Dytiko set is more balanced, suggesting warmer climate and less contrasted climatic conditions. Another way of evaluating the ecological significance of the fossil assemblages is the analysis of the distribution of the body weight of each category of mammals in each fauna. When possible we used the cenogram method or a multivariate analysis of the number of species in each weight class (excluding small mammals, which are very rare in Macedonia); we have analysed in this way 25 fossil and 23 recent localities. We show that, although all the fossil localities are separated from the recent ones, it is possible to deduce an open environment in “Ravin de la Pluie” and a more forested one in Dytiko.