1. E. Frey and W. Munk, Staatliches Museum für Naturkunde Karlsruhe, Erbprinzenstrasse 13, D-76133 Karlsruhe, Germany.
2. H.-D. Sues, Department of Palaeobiology, Royal Ontario Museum, 100 Queen's Park, Toronto, ON M5S 2C6, and Department of Zoology, University of Toronto, Toronto, ON M5S 3G5, Canada.