Biogeography of circum-Mediterranean Miocene-Pliocene rodents; a revision using factor analysis and parsimony analysis of endemicity

The biogeographic relationships of North African Miocene-Pliocene rodent faunas are assessed using two different methods, factor analysis and parsimony analysis of endemicity. The Mediterranean basin is a true biogeographic province. Within it, North Africa makes up a sub-province of its own, only slightly closer to the Ibero-Occitanian sub-province than to the eastern Mediterranean one. These three sub-provinces retain their permanency over time, localities within them being clustered according to their geological age rather than by geographic location. The Miocene-Pliocene is a period of strong, but transitory similarity between the north and south, while there is a steady trend toward homogenisation of the northern Mediterranean. Most of the exchanges occur, through France, between the eastern Mediterranean and eastern Spain, and between the latter area and the rest of Iberia and North Africa, while there are very few trans-Mediterranean and southern longitudinal exchanges.