The Maragheh hipparions, late Miocene of Azarbaijan, Iran

Morphological analyses of hipparionine astragali, calcaneum, third phalanx and metapodials from the late Miocene locality of Maragheh, Iran, was carried out using bivariate plots and log10 ratio diagrams. The results, together with previous studies on cranial and dental material, have allowed us to characterise and define the following equid species in the Maragheh assemblage: Hipparion gettyi, aff. Hippotherium brachypus, Cremohipparion aff. moldavicum, Cremohipparion matthewi and Hipparion campbelli. These species are arrayed in three successive biostratigraphic intervals: H. gettyi, late Vallesian Lower Maragheh horizon; aff. H. brachypus and Cr. aff. moldavicum, early Turolian Middle Maragheh levels; and H. campbelli, late early Turolian Upper Maragheh interval. The small hipparion, Cr. matthewi, would appear to range throughout all biostratigraphic intervals of Maragheh. The proposed taxonomic and biostratigraphic resolution here is slightly different from previous studies especially in the recognition of aff. H. brachypus instead of Hipparion prostylum. The Maragheh hipparion assemblages are well correlated to those from Turkey, Greece, the Balkans and Black Sea region and are clearly different from those of Central and Western Europe, central Asia, China and Africa. Maragheh Cremohipparion is related to species of Cremohipparion from Greece, China and the Siwaliks. A clear niche differentiation based on palaeodiet studies has been revealed in Maragheh hipparions, indicative of different environmental adaptations amongst these species.