1. Department of Biogeology; Institute of Paleobiology; Polish Academy of Sciences; PL-00-818 Warsaw Poland
2. Department of Paleontology and Stratigraphy; Faculty of Earth Sciences; University of Silesia; PL-41-200 Sosnowiec Poland
3. Museum of Paleontology and Department of Earth and Environmental Sciences; University of Michigan; Ann Arbor MI 48109-1079 USA