The present book is the first detailed review of the Paleogene avian fossil record on a worldwide scale. Numerous well-preserved fossil bird remains from this geological period, which covers the time span from the end of the Mesozoic era to the beginning of the Miocene, have been described in the past two decades. Some of these not only provide information on morphological transformations in the evolutionary history of the extant avian taxa, but are also of great significance for an understandi ...