Martin Cotte

•    Evolution and Palaeoecology of the Carnivora & Metatheria
•    Great American Biotic Interchange
•    Geobiology
•    Ecosystem reconstruction
•    Extinction events
 

Preliminary title:

Palaeoecology and evolution of the carnivorous mammalian faunas of South America from the Late Miocene to the Pleistocene: Insights from stable isotopic signatures (13C, 15N, 18O) in fossil bones and teeth
South America was isolated during most of the Tertiary and developed a very particular mammalian fauna. In contrast to other continents, the carnivore adaptive zone was filled by crocodiles, large snakes and birds, and metatherian mammals (Sparassodonta). The group Sparassodonta was diverse during the Tertiary with a broad range of sizes (≈ 2-50 kg). This diversity decreased towards the late Miocene and the group became extinct at the middle Pliocene (≈ 3 Ma). The cause of this decline and extinction may have been the immigration of placental carnivores to South America (≈ 6-7 Ma ago), which putatively competed with the sparassodonts. This hypothesis was recently criticized and the Ecological Replacement hypothesis was proposed, which postulates that the invading placental carnivores filled ecological niches left empty after the extinction of previous occupants (marsupial carnivores) due to other causes, such as environmental changes. Under the Ecological Replacement scenario, environmental changes should lead to changes in the isotopic relationships among fossil taxa, while in the Ecological Competitive Displacement scenario, similar isotopic relationships should be observable between extinct marsupial predators and the placental predators that replace them.
 

Palaeoecology of Pleistocene bison using stable isotopes (13C, 15N, 18O) 
The European bison is one of the last large herbivorous species in Europe. Brought nearly to extinction in the past, it has narrowly survived and is now subject to intense conservation efforts. Historically regarded as a forest specialist the species is now kept in several forest reserves throughout Europe. However, the problematic condition of the species' foraging ability during the winter months has raised the question of whether the forest is a viable habitat for tham at all. This study aims to answer the question of the habitat preference of previos bison species in Europe. By employing stable isotope analysis this study investigates the diet and therefore habitat preference of fossil bison since the early Middle Pleistocene. The results of the genus' ecological development through time will hopefully contribute to the discussion of bison conservation in Europe and the future course for the species.
 

2013-    PhD student at the University of Tübingen, faculty of Science, Department of Geosciences, Biogeology division under Prof. Dr. Hervé Bocherens and Prof. Dr. Madelaine Böhme
2008-2013    B.Sc. and M.Sc. in Geosciences, University of Tübingen, Germany