Mammalian biostratigraphy, geochronology, and zoogeographic relationships of the Late Miocene Maragheh fauna, Iran

Abstract

The classical Late Miocene Maragheh fauna has been collected and studied sporadically for nearly 150 years. This study gives a comprehensive account of the entire mammalian fauna recovered at Maragheh to date and its biostratigraphic, biogeographic and geochronologic contexts. The sequence is divided into Lower, Middle and Upper biostratigraphic intervals, ranging fRom ca. 9.5 my to 7 my in age, based on the first appearance of a potential evolutionary series of hipparionine horses: “Hip-parion” gettyi, Hipparion prostylum, and Hipparion campbelli. Stratigraphical ranges of individual mammalian species are given, and biostratigraphic intervals are characterized. A comprehensive zoogeographic analysis of the entire Maragheh mammalian fauna shows its relationships with late Miocene–early Pliocene “savanna-mosaic” assemblages of Eurasia and Africa. It has been found that the Maragheh genera which have the broadest geographic distribution were part of a late early Miocene pan-Eurasian and African dispersal event. Their subsequent diversification may be attributable to biogeographic vicariance with both tectonic and paleoenvironmental factors playing contributing roles.