Turnover pulse or Red Queen? Evidence from the large mammal communities during the Plio-Pleistocene of Italy

This study investigates the effect of climate changes (during the Ice Ages) on the evolution of Plio-Pleistocene large land mammal communities of the Italian peninsula. We recognized paleocommunities by using both the classic, biochronologic approach and with a special type of cluster analysis able to recognize a statistically discrete number of paleocommunities. These approaches ensure the potential for including rare species, dilute taphonomic biases, and give stronger emphasis on the conjoint occurrence of species. Irrespective of the way we partitioned the fossil record, our results are consistent with the prediction that climate changes affected Turnover Rates (TRs). We found out that only cold shifts in climate were effective in influencing communities’ turnover. Phylogenetic and ecologic inheritance from Pliocene (warmer) climate probably made large mammal communities by far more sensitive to cold than to warm shifts in global temperature. Eventually, we discuss various potential flaws affecting studies on TRs. Those flaws depend on the phylogenetic, geographic and body-size level of investigation. The existence of these restrictions makes studies on turnover hardly comparable with each other.