Acta Musei Moraviae

Neogene mammals of the Mikulov area

Neogene terrestrial vertebrates occur only rarely in the Moravian part of Central Paratethys, and usually derive from poorly known localities or localities that are currently lost. As such, their study can be very difficult. Interestingly, new finds are often being reported following reassessments of old collections. A good example is the material originating from the surroundings of Mikulov (=Nikolsburg in German), located on the western edge of the geologically well-explored Vienna Basin. Fossil mammals from the Neogene deposits have been known there since the 19th century. Until the first half of the 20th century, the autochthonous Neogene vertebrates of the Mikulov area have been found in two or three different stratigraphic levels (Badenian, Pannonian, upper Pannonian–?Pontian). Despite this, some authors considered the Neogene vertebrates from Mikulov as being of the same age. The aim of this work is to revise the stratigraphic setting of the localities through comparisons of all available information (geology, position, duration) with taphonomic data obtained from the old collections (Natural History Museum Vienna, Department of Palaeontology at the University of Vienna, Moravian Museum, Regional Museum in Mikulov, Department of Geological Sciences at Masaryk University). The study showed that the bones and teeth from the Hrušky Formation (upper Badenian) and Valtice Beds (Pannonian–?Pontian) differ significantly in both, their taphonomy and preservation, which is probably caused by different contents of Mn, Fe, and CaCO₃ in the middle and upper Miocene deposits. The results indicate that most of the fossil vertebrates from the area south of Mikulov come from the Bzenec Formation (Pannonian). Neogene sediments with vertebrates represent sedimentary relics of rivers that have debouched into Vienna Basin in the Mikulov area since the middle Badenian until Pannonian-?Pontian. Therefore, redepositions of bones from older to younger deposits could occur. In the youngest (upper Pannonian–?Pontian) Neogene lithostratigraphical unit in the Mikulov area (Valtice Beds), autochthonous fossil mammals have been found only in Hlohovec, whereas in the Mikulov area only bones possibly redeposited from the Badenian have been identified.