1. Department of Organismic & Evolutionary Biology and Museum of Comparative Zoology Harvard University Cambridge Massachusetts 02138 USA
2. Institute of Geosciences, Freie Universität Berlin Malteserstrasse 74‐100, Haus C D‐12249 Berlin Germany
3. Unaffiliated Round Lake Beach Illinois 60073 USA
4. Institute of Geosciences University of São Paulo 05508‐080 São Paulo Brazil
5. Geology Department Pomona College Claremont California 91711 USA
6. Unaffiliated Wellsville Utah 84339 USA