Snakes comprise more than 3,800 extant species found on all major continents except Antarctica. Morphologically and ecologically diverse, they include burrowing, arboreal, and marine forms, feeding on prey ranging from insects to large mammals. Snakes are strikingly different from their closest lizard relatives, and their origins and early diversification have long challenged and enthused evolutionary biologists. The origin and early evolution of snakes is a broad, interdisciplinary topic for which experts in palaeontology, ecology, physiology, embryology, phylogenetics, and molecular biology have made important contributions. The last 25 years has seen a surge of interest, resulting partly from new fossil material, but also from new techniques in molecular and systematic biology. This volume summarises and discusses the state of our knowledge, approaches, data, and ongoing debates. It provides reviews, syntheses, new data and perspectives on a wide range of topics relevant to students and researchers in evolutionary biology, neontology, and palaeontology.