Taxonomic study of the pigs (Suidae, Mammalia) from the late Middle Miocene of Gratkorn (Austria, Styria)

The locality of Gratkorn of early late Sarmatian age (Styria, Austria, Middle Miocene) has yielded an abundant and diverse fauna, including invertebrates, micro-vertebrates and large mammals, as well as plants. As part of the taxonomical study of the mammals, two species of suids, are described here and assigned to Listriodon splendens Von Meyer, 1846 and Parachleuastochoerus steinheimensis (Fraas, 1870). As the generic affinities of the latter species were subject to debate, we present a detailed study of the evolution of the European Tetraconodontinae. The morphometric changes that occurred in a series of fossil samples covering the known temporal ranges of the species Pa. steinheimensis are documented. It is concluded that Parachleuastochoerus includes three species, namely Pa. steinheimensis, Pa. huenermanni and Pa. crusafonti. Evolutionary changes are recognised among the Pa. steinheimensis fossil samples. In addition, it is proposed that the subspecies Pa. steinheimensis olujici was present in Croatia long before the genus dispersed further into Europe.