Insectivores and bat (Mammalia) from the late Middle Miocene of Gratkorn (Austria): biostratigraphic and ecologic implications

摘要

The discovery of a late Sarmatian (latest Middle Miocene) small mammal fauna at the base of the clay pit St. Stefan near Gratkorn is of primary importance for the biostratigraphic and ecologic comprehension of the faunal evolution during the late Middle Miocene of Central Europe. In this paper five species of insectivores and one bat are described. The gymnure Schizogalerix voesendorfensis is the most abundant species of the small mammal fauna. The Gratkorn sample represents the earliest occurrence of the species in the fossil record. A single molar of a second, large-sized Galericinae cannot be attributed to any known species. The new talpid Desmanodon fluegeli n. sp.shares similarities with the Anatolian lineage D. minor / D. major. An exceptionally well preserved mandible of the large shrew Dinosorex cannot be determinate at the species level. In addition, some rare remains of the bat cf. Myotis sp. are also reported. From biogeographical point of view the insectivore fauna can be related to eastern Central European / Anatolian assemblages. Although taphonomic biases are suspected, the environmental conditions proposed on the basis of sedimentary analyzes (open forest with moist soil) can contribute to the low alpha diversity of insectivores in this locality.