1. Institute of Earth Sciences, University of Silesia in Katowice, Będzińska 60 41-200 Sosnowiec, Poland;
2. Department of Palaeontology, University of Vienna, Josef-Holaubek-Platz 2, 1090 Vienna, Austria;
3. Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland;