1. Department of Geosciences, University of Tübingen, Hoelderlinstrasse 12, Tübingen, Germany
2. Institute of Botany, Technische Universität Dresden, Zellescher Weg 20b, Dresden, Germany
3. Nicholas School of the Environment and Earth Sciences, Levine Science Research Center, Duke University, Durham, NC, USA
4. Deptartment of Palaeontology, State Museum of Natural History Stuttgart, Rosenstein 1, Stuttgart, Germany
5. Department of Physics, Technical University of Denmark, Fysikvej Building 309, Kgs. Lyngby, Denmark