Review of the Pliocene-recent holarctic marmots [Revue des marmottes holarctiques du Pliocène récent].

Résumé

The detail analysis of the paleontological data has revealed that marmots are of the New World origin. During their long history of evolution from the Late Oligocene to the recent time there were at least four invasions to Palearctic region and faunal interchanges existed until the end of Pleistocene. The first invasion probably took place at the beginning of the Oligocene, second during the Early Miocene, the third at the end of Pliocene-beginning Pleistocene and the last during Late Pleistocene glaciation. Two centres of marmot diversification could be recognized – North America and Central Asia. Previously marmots were inhabitants of lowland areas, mainly open landscapes whit lighted forest. Later on with uplifting of the most of Eurasian and North American high mountains during Pliocene end Pleistocene some group of marmots became inhabitants of alpine environment and the other are adapted to plain steppes. From the beginning of the Miocene more than 25 extinct marmot taxa are known in Europe (8), in Asia (around 14) and North America (7) including the extinct forms of the modern species. Some of them, as Marmota bobak, were widely distributed in Eurasia, some of them occupied the restricted area.In modern faunas 15 extant species of marmots are recognized on the base of complex analysis such as morphological, karyological, biogeographical and others.