Systematics and palaeoecology of Ruminantia (Artiodactyla, Mammalia) from the Miocene of Sandelzhausen (southern Germany, Northern Alpine Foreland Basin)

Abstract

In more than 20 years of excavation at the fossil lagerstatte Sandelzhausen (Early/Middle Miocene boundary, Burdigalian/Langhian boundary, early middle MN5) a substantial amount of fossil remains of ruminants have been recovered. Currently, it is the largest recorded assemblage of ruminants from the Miocene Northern Alpine Foreland Basin. More than 1,000 teeth, almost 70 antler remains and one skull enable the identification of five ruminants, namely the tragulid Dorcatherium crassum, the palaeomerycid Germanomeryx n. g. fahlbuschi n. sp., and the cervids Lagomeryx parvulus, Lagomeryx pumilio, and Heteroprox eggeri n. sp. Lagomeryx parvulus and L. pumilio have the most extensive record yet known for these species, opening up a much more complete view of them 120 years after the discovery of the type materials. The newly established G. n. g. fahlbuschi n. sp. and H. eggeri n. sp. enlarge our knowledge on the taxonomic composition of Miocene European Ruminantia. Because of the exceptionally large number of specimens, nearly all tooth positions of all five species are documented, thereby completing hitherto partially known character sets. The investigation comprises extensive taxonomic descriptions of all species represented and an interpretation of the palaeoecology based on an analysis of the community structure. This clearly suggests a humid closed canopy forest interspersed with temporary and perennial waters and accompanying open areas. Moreover, a comparison with other, stratigraphically close Molasse Basin communities emphasizes the various peculiarities of the Sandelzhausen community (low species number, cervid-dominance, dominance of L. pumilio over L. parvulus, non-dominance of very small-sized ruminants, comparably high portion of palaeomerycids, all species being browsers, no Eotragus and no Amphimoschus). The investigation also clarifies the similarity with the communities from Undorf and Viehhausen (Germany, MN5). The deduced dynamics in community structure of the late Early and early Middle Miocene Northern Alpine Foreland Basin provides further support for the current hypothesis of a vast wetland environment under the strong influence of alternating dry and flood seasons.