Taxonomy, biostratigraphy and palaeoecology of Choerolophodon (Proboscidea, Mammalia) in the Miocene of SE Europe-SW Asia: implications for phylogeny and biogeography

Abstract

The Miocene elephantoid Choerolophodon from SE Europe-SW Asia is studied, based on the Greek localities of Thymiana, Axios Valley, Pikermi, Samos and Nikiti-2. Although this genus is well documented in Greece, there is no recent taxonomic study and its biostratigraphy and palaeoecology had never been examined in detail. Three choerolophodont species are recognized in SE Europe–SW Asia: the Middle Miocene C. chioticus (late Orleanian, MN 5), and the Late Miocene C. anatolicus (early Vallesian, MN 9) and C. pentelici (late Vallesian–Turolian, MN 10–MN 13). The latter species is divided into a primitive morph, dated to the late Vallesian and possibly earliest Turolian, and an advanced morph from the Turolian. At the end of the Miocene Choerolophodon disappeared. With respect to the geographical distribution of Choerolophodon, the genus is very well documented in SE Europe–SW Asia but it is unknown from Central, Western and Northern Europe, a fact which is attributed to ecological factors. The phylogenetic relationships of all known choerolophodont species from the Miocene of the Old World are examined using a cladistic analysis, and their proposed biogeography is discussed. Finally, the palaeoecology of Late Miocene Choerolophodon from Northern Greece is studied through a dental microwear analysis, revealing that Choerolophodon foraged mainly on grasses, a type of vegetation widespread in open environments. These palaeoecological results are in agreement with previous environmental reconstructions for the Late Miocene of Greece.