Rodents from the Upper Miocene Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey)

Abstract

The upper Miocene assemblages of rodents collected from two layers of the type section of the Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey) are described. The assemblage from the lower level is considerably less diverse than that from the upper level. It contains Progonomys together with Megacricetodon, which is a very unusual association. The assemblage from the upper layer shows a relatively high diversity with four species of Gliridae instead of only one in the lower layer. Apart from the more diverse Gliridae, Byzantinia sp., Spermophilinus, Keramidomys and Myocricetodon appear in the upper layer. The absence of Murinae in the assemblage from the upper layer is very unexpected, because they usually become dominant soon after their arrival. Their unusual subsequent absence may be either due to a significant change from an open and humid environment to a more dry and wooded environment or to taphonomic bias. Both rodent faunas are assigned to local zone I, which is correlated to the lower Vallesian (MN9).