Richard H. Madden has been a Research Associate at the Duke University Medical Center for the last twenty years where he assists in the teaching of anatomy in the School of Medicine. His current research interests include the relationship between climate, earth surface processes, and the geographic and temporal patterns of soil ingestion and tooth wear in mammalian herbivores as ... Read morethese may relate to evolution of tooth mineral volume. Alfredo A. Carlini is a Research Paleontologist of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Professor of Comparative Anatomy at the National University of La Plata, Argentina. His research interests focus on the morphological diversity, evolutionary trends, ontogeny, systematics, biostratigraphy, and biogeography of armadillos and living and fossil xenarthrans, with over 100 scientific publications in books and journals. Maria Guiomar Vucetich is a Research Palaeontologist of Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Professor of Vertebrate Palaeontology at the National University of La Plata, Argentina, where she has worked since 1971. Her research interests involve the evolutionary history of caviomorph rodents and she has published nearly 100 scientific articles on this topic. Richard F. Kay is Professor of Evolutionary Anthropology, and Earth and Ocean Sciences at Duke University, North Carolina, where he has worked since 1973. He has edited five books and authored more than 200 research papers on primate paleontology, functional anatomy, adaptations, and phylogenetics. He is an elected Fellow of the American Association for the Advancement of Science (USA). Show Less