New giraffid (Artiodactyla) material from the Lower Pleistocene locality of Sésklo (SE Thessaly, Greece): evidence for an extension of the genus Palaeotragus into the Pleistocene

The peri-Mediterranean and western Asian Plio-Pleistocene faunas are characterised by the sporadic presence of a palaeotragine taxon with a complex nomenclatural history, usually referred to the genus Mitilanotherium. Due to its rarity, its morphological characters are incompletely known. Recently excavated giraffid material in the Lower Pleistocene locality of Sésklo (Thessaly, Greece) includes an almost complete skull that provides a better knowledge of the taxon’s morphology. The skull is long with a proportionally elongate postorbital part. Dorsally it is very wide, and has a markedly flat cranial roof. The long ossicones emerge supraorbitally and are widely separated. The dentition is brachyodont with short premolar section with regard to other palaeotragines. A stratigraphically associated atlas is very large and robust, implying a very powerful neck. As indicated by the comparisons based on the new material, the samples previously referred to Mitilanotherium and related genera form a homogeneous conspecific group, similar to the Late Miocene palaeotragine species, especially those of the genus Palaeotragus. The main common features include the presence of simple supraorbital cranial appendages, the long postorbital part of the skull, and the long and slender metapodials. The implied close phylogenetic relationship between Mitilanotherium and Palaeotragus points to the synonymy between them, extending the stratigraphic range of Palaeotragus into the Pleistocene. Palaeotragus is a long lived, morphologically conservative genus spanning from about 10–11 to almost 1 million years ago. The Plio-Pleistocene species, P. inexspectatus, was adapted to open and dry habitats of the peri-Mediterranean and SW Asian region.