Abstract:
During transition from Middle to Late Miocene strong geographic, climatic, and biotic changes had a
strong impact on aquatic and terrestrial ecosystems in Central Europe. Large-scale erosion in the
Central Paratethys realm caused a lack of terrestrial sediments from this time period and thus resulted
in a remarkable palaeobiological “blackout” for the record on land in this region from late Sarmatian to
early Pannonian.
The here presented Gratkorn locality, well dated to an age of 12.2/12.0 Ma (early late Sarmatian)
provides a rich vertebrate assemblage (species diversity as well as total number of specimens) with 65
recorded species up to date. It represents a unique window to the terrestrial record of this time period
and helps to understand the evolution of vertebrate faunas during the Middle-Late Miocene transition.
Remains of herbivorous large mammals were morphologically described and assigned to the following
taxa (Suidae not part of this thesis): Deinotherium levius vel giganteum, Aceratherium sp.,
Brachypotherium brachypus, Lartetotherium sansaniense, Chalicotherium goldfussi, Anchitherium sp.,
Listriodon splendens, Parachleuastochoerus steinheimensis, Dorcatherium naui, Micromeryx
flourensianus, ?Hispanomeryx sp., Euprox furcatus, Palaeomerycidae gen. et sp. indet., and
Tethytragus sp..
Except of Dorcatherium naui, presence and evolutionary stage of the large mammals are well in
accordance with a late Middle Miocene assemblage. The records of Euprox furcatus and Micromeryx
flourensianus comprise the first for the Styrian Basin and Hispanomeryx has not been recorded for
Central Europe so far besides the locality Steinheim a. A.. Dorcatherium naui is considered a typical
faunal element of the Late Miocene and has been described only recently from Middle Miocene
localities. With the rich material from Gratkorn assignation of this species to a more selenodont
phylogenetic lineage together with Dorcatherium guntianum and well distinct from Dorcatherium
crassum can be verified and the descent of the species from the latter thus shown to be unlikely.
The fossil assemblage from Gratkorn is considered an autochthonous taphocoenosis without any
significant time averaging or faunal mixing. Most likely the accumulation did not last longer than a few
years or decades and local accumulation of large mammal bones was the result of scavenging.
Based on the taxonomic record, morphology of skeletal and dental elements, and especially isotope
analyses (δ18OCO3, δ13C, 87Sr/86Sr), dominance of C3 vegetation, semi-arid and subtropical climate
with distinct seasonality, and too little precipitation for closed canopy woodlands can be reconstructed
for the wider area around the locality. The landscape provided diversity in plant resources to allow
occupation of different niches by herbivorous large mammals: subcanopy browsing, rooting, top
canopy browsing, facultative frugivory, and mixed feeding. Comparison with data from other Miocene
localities from different areas and time slices showed rather stable niche partitioning for the
herbivorous large mammal species. Thus these seem to be affected only to a minor degree by climatic
conditions but rather represent a typical partitioning for a Middle Miocene ecosystem.
Neogene