This book includes contributions from the Proceedings of the International Symposium at the ASIH (American Society of Ichthyologists and Herpetologists) Annual Meeting in St. Louis, Missouri, on 14 July 2007. The volume presents the current state of phylogenetic knowledge of the origin of teleosts and the interrelationships of teleost groups, both key issues in fish systematics, based on both morphological and molecular evidence. The many contributors to the volume present and evaluate progress in studying both characters and taxa and in establishing databases that will be of use in future.