Spencer G. Lucas. New Mexico Museum of Natural History, 1801 Mountain Road N. W., Albuquerque, 87104 New Mexico, USA. spencer.lucas@state.nm.us

Spencer Lucas received a B.A. from the University of New Mexico in 1976, and M. S. (1989) and Ph.D. (1984) degrees from Yale University. His research interests have primarily focused on vertebrate biostratigraphy, particularly of the Mesozoic. Lucas is particularly interested in the application of vertebrate fossils to problems of the geologic timescale. He has conducted field research primarily in the western United States, but also in China, Kazakstan, Georgia, Mexico, Costa Rica and Nicaragua.

Lucas began fieldwork on the Carboniferous-Permian transition in New Mexico during the late 1990s. This research has focused on diverse aspects of the stratigraphy, biostratigraphy and paleontology of the marine and nonmarine strata that crop out across the state.

Since 1988, Lucas has been Curator of Geology and Paleontology at the New Mexico Museum of Natural History and Science.

Larry F. Rinehart. New Mexico Museum of Natural History, 1801 Mountain Road N. W., Albuquerque, 87104 New Mexico, USA. larry.rinehart@earthlink.net

Larry Rinehart worked as an electronics technician and later as an electrical engineer for the U. S. Navy and Sandia National Laboratories. Most recently, he was the preparator at the New Mexico Museum of Natural History and Science. His principal research interests are growth, variation, and allometry, mostly of Pennsylvanian, Permian, and Triassic fossil populations.

Matthew D. Celeskey. New Mexico Museum of Natural History, 1801 Mountain Road N. W., Albuquerque, 87104 New Mexico, USA. matt.celeskey@hmnh.org

Matthew Celeskey is an artist, exhibition designer and researcher. He received a B.F.A. from Carnegie Mellon University in 1995 and has created illustrations and designs for museum exhibits for more than 20 years. He has published anatomical studies and reconstructions of animals from the Cambrian through the Quaternary, but is particularly interested in tetrapods from the Permian and Triassic. Matt Celeskey is currently a research associate at the New Mexico Museum of Natural History and Science.