Phylogeny -- Molecular Phylogenetics of the Callitrichidae with an Emphasis on the Marmosets and Callimico -- The Systematics and Distributions of the Marmosets (Callithrix, Callibella, Cebuella, and Mico) and Callimico (Callimico) (Callitrichidae, Primates) -- The Vocal Identity of the Callithrix Species (Primates, Callitrichidae) -- Reproductive, Social, and Cognitive Behavior -- Social Behavior of Callimicos: Mating Strategies and Infant Care -- Genetic Structure Within and Among Populations of the Common Marmoset, Callithrix jacchus: Implications for Cooperative Breeding -- Mating Systems and Female-Female Competition in the Common Marmoset, Callithrix jacchus -- Balancing Cooperation and Competition in Callitrichid Primates: Examining the Relative Risk of Infanticide Across Species -- Social Hierarchy and Dispersal in Free-Ranging Buffy-Headed Marmosets (Callithrix flaviceps) -- Emigration as a Reproductive Strategy of the Common Marmoset (Callithrix jacchus) -- Social and Physical Cognition in Marmosets and Tamarins -- Ranging Behavior and Locomotion -- Limited Dispersal and Genetic Structure of Silvery Marmosets (Mico argentatus) in the Fragmented Landscape of Central Amazonia -- Habitat Use and Ranging Behavior of the Silvery Marmoset (Mico argentatus) at Caxiuanã National Forest (Eastern Brazilian Amazonia) -- Ranging Patterns of Callimico goeldii (callimico) in a Mixed Species Group -- A Comparative Study of the Kinematics of Trunk-to-Trunk Leaping in Callimico goeldii, Callithrix jacchus, and Cebuella pygmaea -- Locomotion, Postures, and Habitat Use by Pygmy Marmosets (Cebuella pygmaea) -- Anatomy -- Mother's Little Helper? The Placenta and Its Role in Intrauterine Maternal Investment in the Common Marmoset (Callithrix jacchus) -- Size and Shape in Callimico and Marmoset Skulls: Allometry and Heterochrony in the Morphological Evolution of Small Anthropoids -- Cranial Morphology of the Dwarf Marmoset Callibella in the Context of Callitrichid Variability -- The Functional Significance of Jaw-Muscle Fiber Architecture in Tree-Gouging Marmosets -- The Evolutionary Morphology of Tree Gouging in Marmosets -- Marmoset Postcrania and the Skeleton of the Dwarf Marmoset, Callibella Humilis -- Conservation -- Conservation Status of Pygmy Marmosets (Cebuella Pygmaea) in Ecuador -- Conservation of the Marmosets and Callimicos. The Smallest Anthropoids:The Marmoset/Callimico Radiation represents a comprehensive examination of the callimico/marmoset clade, including the smallest anthropoid primates on earth. It explores these diminutive primates from a variety of perspectives including: phylogeny; reproductive, social, and cognitive behavior; ranging behavior and locomotion; anatomy; and conservation. In the last twenty years, the number of taxa recognized in this group has increased from three genera and five species to five genera comprising at least 22 species. Additionally, our understanding of the evolutionary relationships among these taxa has undergone substantial revision, and all are now considered to be closely related to one another (including callimicos). This volume is the first to synthesize data on these newly recognized taxa. It features contributions from geneticists, anatomists, and behaviorists around the world, providing access to major findings of key international researchers whose work has not been easily available to English-speaking scholars. These contributors use field and lab data to test major hypotheses on behavior, evolution, cognition, and other issues. The Smallest Anthropoids:The Marmoset/Callimico Radiation is a timely forum that identifies future avenues of action necessary to more fully understand and protect this intriguing radiation of diminutive monkeys. It will be of value to field ecologists, conservation groups, individuals working with captive marmosets, natural resource managers in South America, and NGO's, as well as to primatologists and zoologists interested in social behavior, locomotion and biomechanics, morphology, reproductive behavior, and biology. Susan M. Ford is Associate Professor and Chair of the Department of Anthropology, and past Director of the Center for Systematic Biology, Southern Illinois University. Leila M. Porter is Associate Professor in the Department of Anthropology, Northern Illinois University. Lesa C. Davis is Associate Professor of the Department of Anthropology and Special Assistant to the President, Northeastern Illinois University, and Research Associate in the Field Museum of Natural History.