New fossil Carnivora from Thailand: transcontinental paleobiostratigraphic correlations and paleobiogeographical implications

摘要

The study and reanalysis of late Oligocene and middle Miocene dental material from Thailand provides evidence for long-distance stratigraphic correlations, and thus sheds new light on past terrestrial connections between Southeastern Asia and Europe. Here we report the oldest occurrence of Ursidae in southern Asia - a late Oligocene fossil from Nong Ya Plong previously referred to Mustelida but reattributed here to Cephalogale aff. geoffroyi (Ursidae, Hemicyoninae, Cephalogalini). We also describe a new Viverridae, Semigenetta cf. steinheimensis, from the middle Miocene carnivoranrich locality of Mae Moh. The presence of these two taxa in Western Europe reinforces stratigraphic correlations of the MP29 and MN7-8 fossil sites with Southeast Asian localities. Members of the tribe Cephalogalini may have migrated several times from Asia to Europe, or vice-versa, during the Oligocene and early Miocene via either a northern route across northern China, or a southern route traversing southern Asia and the Middle East. Semigenetta could have dispersed along a corridor through Central Asia or a southern Asian route into Thailand during the middle Miocene. Our study thus indicates that medium- or large-sized carnivorans constitute a useful tool for reconstructing the paleobiogeography of extinct species.