In Sicily few studies have been devoted to the climatic-environmental changes of the Pleistocene and Holocene period. Most of the studies on Quaternary vertebrates in Sicily have been focused on the evolutionary-taxonomic aspects of the fauna. Sicily experienced at least four vertebrate dispersal events during Quaternary time, which are of different provenence (African and/or European) and have been controlled by filtering barriers of different intensities. The marked endemism and the extremely low diversity of the fossil assemblages of early and early-mid-Pleistocene time do not allow detailed interpretations. By way at contrast, younger assemblages are more diverse and, although they display some endemic characters, are similar to those of southern peninsular Italy. The late mid-Pleistocene and early Late Pleistocene assemblages (Elephas mnaidriensis faunal complex) are characterized by the occurrence of a red deer (Cervus elaphus siciliae), a dwarf fallow deer-like endemic megalocerine (Megaceroides carburangelensis), auroch (Bos primigenius siciliae), bison (Bison priscus siciliae), elephant (Elephas mnaidriensis), hippopotamus (Hippopotamus pentlandi), boar (Sus scrofa), brown bear (Ursus cf. arctos) and three large social carnivores (Panthera leo, Crocuta crocuta and Canis lupus). Most of these taxa, except for the megalocerine, are characterized by slightly reduced body size compared with the same taxa from mainland Europe. These assemblages are indicative of a climate with temperate, Mediterranean affinity and of landscapes in which forested areas were associated with more open environments. The relatively low abundance of the red deer and the dominance of the megalocerine in several assemblages suggests that a Mediterranean-type forest locally dominated some of the climatic phases. The assemblages of the youngest Late Pleistocene period on Sicily are characterized by a dramatic drop in diversity, with the disappearance of elephant, hippopotamus, bison, the endemic megalocerine, and the largest predators. This would indicate an environmental crisis probably linked to the drier climatic oscillations of late Pleniglacial time, as is suggested also by the spread of the ground vole, which is the dominant small mammal in several assemblages. The Late Glacial period is characterized by the spread of equids (horse and wild ass), which are indicators of open landscapes and of xerophytic steppe-like cover. The beginning of the Holocene period is characterized by the expansion of forested areas and by a more humid climate, as suggested by the abundance of red deer, and by the dispersal of the common dormouse (Glis glis) and water vole (Arvicola sp.).
