Oligocene ruminants from the Kızılırmak Formation, Çankırı-Çorum Basin, Central Anatolia, Turkey

A new assemblage of ruminants from five distinct Oligocene localities of the Kizilirmak Formation, Central Anatolia, Turkey is described. The tragulids Iberomeryx parvus, and Iberomeryx sp. (large), as well as a probable large lophiomerycid have been recognized. The stem pecoran Dremotherium guthi, cf. Palaeohypsodontus and a large indeterminate Pecora have been identified as well. In the five localities, the majority of the ruminant material is referred to Iberomeryx parvus, but the sample from the locality Tepe 641 (upper member of the Kizilirmak Formation) shows some distinctive characters suggesting a more derived species/forms that probably lived in more open environments. The ruminant taxa recorded in the Kizilirmak Formation are congruent with a Late Oligocene age, probably close in age to the Benara fauna of southern Georgia. The possible occurrence of Palaeohypsodontus in Central Anatolia would significantly expand its geographical range and suggest biogeographical affinities with Central Asia. The ruminant fauna from the Kizilirmak Formation suggests the existence of lowland forests with more open landscapes in central Anatolia during the Late Oligocene.