1. Institute of Geology and Paleontology, Faculty of Science, Charles University, Czech Republic
2. Institute of Geology of the Czech Academy of Sciences, Prague, Czech Republic
3. Department of Geology, Paleontology and Fossil Fuels, Faculty of Geology and Geography, University ʽSt. Kliment Ohridski’, ., Sofia, Bulgaria
4. Department of Environmental Sciences, University of Basel, Basel, Switzerland