1. School of GeoSciences, University of Edinburgh; Edinburgh EH9 3JW U.K.
2. School of Geography, Earth and Environmental Sciences, University of Birmingham; Edgbaston Birmingham B15 2TT U.K.
3. Department of Earth Sciences; Natural History Museum; London SW7 5BD U.K.
4. Department of Paleobiology; Smithsonian Institution; Washington DC 20013 U.S.A.
5. Department of Natural History; Royal Ontario Museum; Toronto Ontario M5S 2C6 Canada
6. Department of Earth Sciences; University of Oxford; South Parks Road Oxford OX1 3AN U.K.
7. Department of Earth Science and Engineering; Imperial College London; London SW7 2AZ U.K.
8. Division of Paleontology; American Museum of Natural History; New York NY 10024 U.S.A.
9. Department of Geology; Baylor University; Waco TX 76706 U.S.A.
10. Department of Earth Sciences; University College London; London WC1E 6BT U.K.
11. New Mexico Museum of Natural History and Science; Albuquerque NM 87104 U.S.A.