1. J. Jernvall, Institute of Biotechnology and Department of Ecology and Systematics, Post Office Box 56, 00014 University of Helsinki, Finland, and Department of Anthropology, State University of New York at Stony Brook, Stony Brook, NY 11794-4364, USA.
2. J. P. Hunter, Department of Anatomical Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794-8081, USA.
3. M. Fortelius, Palaeontology Division, Finnish Museum of Natural History, Post Office Box 11, 00014 University of Helsinki, Finland.