Origination and extinction patterns of mammals in three central Western Mediterranean islands from the Late Miocene to Quaternary

Abstract

An overview of the population histories of three insular realms (Gargano palaeo-archipelago, Sardinia-Maritime Tuscany palaeobioprovince and the Sicilian insular complex) during the Late Miocene and Quaternary are here presented. The complexity of biodiversity changes in the islands is analysed to propose an interpretation of origination and extinction patterns. The study highlighted several important aspects of insular faunas. Evolutionary radiations were found to contribute significantly only to the Gargano faunal diversity, likely because the area was an archipelago at the time.Another interesting result is that large and small mammals do not disperse and become extinct all at the same time on each island. In fact, because of their distinct body sizes, large and small mammals have different dispersal ability and therefore different chances to cross-filtering barriers. But distinct body sizes means also different influence on diversity, resistance to environmental changes and likelihood of extinction. Another important point is that large mammalian carnivores at the top of the trophic net are quite more fragile and susceptible to become extinct than other predators.The study finally shows the clear influence that the intense Middle and Late Pleistocene climate-driven environmental changes had on island communities. The reconstruction of the faunal histories of Sardinia and Sicily shows that without exchanges with the mainland the island system represents a rather stable refuge area not too affected by the changes in the ''physical'' parameters of the environment. In contrast, if the island is frequently connected with the continent, insular faunal assemblages tend to behave as their mainland counterparts. r

A multidisciplinary approach to reveal the Sicily Climate and Environment over the last 20 000 years

“…The arrival of horses and the abundance of the vole Microtus (Terricola) ex gr. savii, supports the occurrence of an open landscape in Sicily [9].…”

“…Even Equus hydruntinus might have disappeared in this interval from Sicily and south Italy, because of the reduction of open landscapes [9,39]. About 14.5 kyr BP, at the beginning of the last deglaciation, there was a low stand of about -90 m [6].…”

“…Such a phenomenon made the mammalian assemblage of Sicily only slightly less diversified with respect to coeval southern Italy assemblages [9]. The dispersion of taxa from southern Italy led to a large turnover, as can be seen in the completely renewed Castello Faunal Complex (20-9 kyr BP).…”

Pannonictis nestii(Galictinae, Mustelidae), a new element in the vertebrate association of the human site of Pirro Nord (Italy, Early Pleistocene)

“…The oldest one is referable to the Late Miocene/Early Pliocene, the other one to the Early Pleistocene. The Neogene vertebrate association, known as the "Mikrotia Fauna" is a not-balanced association characterized by strongly endemic taxa testifying the isolation of the Gargano during the Late Miocene (Masini et al 2008). The Early Pleistocene vertebrate association is rich and highly diversified and contains more than 100 taxa of amphibians, reptiles, birds and mammals (Abbazzi et al 1996;Arzarello et al 2009 and references therein).…”

Diversity, distribution, and conservation of endemic island rodents

“…Wilson and Reeder, 2005), often collected many years ago, and may be extinct (Table 3). All Quaternary endemic rodent species of Mediterranean islands went extinct in historical or prehistoric times (Palombo, 2005;Masini et al, this volume), the only clear exception being the recently described Mus cypriacus (Cucchi et al, 2006) (the systematic status of several other species, like Dipodillus zakariai, requires further clarification from genetic and paleontological investigations; Appendix A). The islands of the Neotropical region, particularly the West Indies, have suffered the highest losses during the last 7000 years at the genus level, with extinction of 14 insular rodent genera and at least 50 species (Woods, 1989;Alcover et al, 1998;MacPhee and Fleming, 2003;see Table 2).…”