Paleoecology 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
We are seeking a highly motivated PhD candidate for a 3-year project funded by the Deutsche Forschungsgemeinschaft (DFG) at the Department of Geosciences of the University of Tübingen (Germany). The position is formally classified as 50% BAT IIa/E13. 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). Sparassodonta was diverse during the Tertiary with a broad range of sizes, but this diversity decreased towards the late Miocene and the group became extinct at the middle Pliocene. The cause of this decline and extinction may have been immigration of placental Carnivores to South America, which putatively competed with the sparassodonts (Ecological Competitive Displacement Hypothesis, ECD). This hypothesis was recently criticized and the Ecological Replacement (ER) hypothesis was proposed, which postulates that newcomers (placental carnivores) filled ecological niches left empty after the extinction of previous occupants (marsupial carnivores) due to other causes, such as environmental changes. This subject is currently being studied using morphometrics, which, however, may be biased by a
Here we propose using stable isotopes (13C, 15N, 18O) to complement the study of the evolution of the carnivore guild during the late Cenozoic in Argentina. This purely phenotypic approach will yield direct information on actual ecological changes and allow to test the ER and ECD scenarios.
The ideal candidate will be highly motivated and have a stated interest and/or experience especially in bone and tooth isotopic geochemistry to reconstruct paleodiets. Previous degrees in geology or biology are therefore advantageous. Whereas proficient English skills are mandatory as well as decent knowledge of Spanish (fieldwork and sampling will take place in Argentina), knowledge of German is helpful, particularly for social interactions, but not necessary. We explicitly welcome national and international candidates. The University of Tübingen, one of Germany’s Elite Universities, is located in the historic university town of Tübingen in the southwest of Germany, approximately one hour south of the metropolitan region of Stuttgart, and close to the Black Forest and the Swabian Jura. The Biogeology Workgroup of the Department of Geosciences provides a dynamic and highly international work environment.
Please send your application, including CV, list of publications, a list of three referees, and a short letter of motivation to the address below, preferably by email. We will start reviewing applications by the end of August and ask the referees of selected candidates for letters of support by the beginning of September. The project is officially scheduled to start October 1, 2012, but the starting date can be delayed to the winter or early spring of 2013.
Prof. Dr. Hervé Bocherens
Department of Geosciences
University of Tübingen