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.

Keywords:

• Proboscidea
• Choerolophodon
• Miocene
• Greece
• Axios Valley
• systematics

Acknowledgements

G. Konidaris would like to thank the following persons for allowing access to collections and offering help during his stay at various museums and institutions: G. Theodorou and S. Roussiakis (AMPG), U. Kotthoff (GPIH), L. Kordos (HGI), M. Gasparik (HNHM Budapest), R. Marchant (MGL), P. Tassy and S. Sen (MNHN), U. Göhlich (NHMW) and M. Ivanov (SU). This study was partially funded by SYNTHESYS (European Union-funded Integrated Activities grant) for visits of the first author to Vienna [AT-TAF-3825] and Budapest [HU-TAF-1683], and by the international collaborative grant PICS CNRS 5182 (CNRS and Aristotle University of Thessaloniki). We are grateful to several colleagues and students, who took part in the excavations of Axios Valley, Nikiti and Samos helping us to collect the majority of the studied material. We thank two anonymous reviewers for making constructive comments and suggestions leading to an improvement of the manuscript.

Supplemental data

Supplemental material for this article can be accessed online at: http://dx.doi.org/10.1080/14772019.2014.985339.