Knowledge of fossil sharks (chondrichthyans) has advanced tremendously over the past decade, giving scientists a window into a historically understudied branch of the evolutionary tree of fishes, and revealing anatomies and ecologies just as diverse and fascinating as those of bony fishes (osteichthyans). This volume assembles cutting-edge research on the biology, anatomy, and evolution of sharks and bony fishes, featuring works by paleobiologists and associated researchers from 11 countries, spanning topics from taxonomy to statistical methodology, in honor of Professor John G. Maisey, for his pioneering work on Paleozoic chondrichthyan anatomy, taxonomy, and paleobiogeography over his half-century career at the American Museum of Natural History. With an introduction and 16 chapters, this volume erects two new families and two new genera, and provides 160 figures and illustrations, and 29 plates, including the most comprehensive collection of high-resolution images of a rare fossil shark held predominantly in private collections.