1. NASA Goddard Spaceflight Center, Code 691, Greenbelt, Maryland 20771, USA
2. Department of Geosciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
3. Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois 60022, USA
4. Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Panama
5. ISEM, Université de Montpellier, CNRS, EPHE, IRD, 34090 Montpellier, France
6. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, D.C. 20013, USA