The Cretaceous was one of the most dynamic periods in the history of the vertebrates. Some groups, such as dinosaurs and pterosaurs, reached their acme, only to then decline and die out at the end of the period. Others, notably the mammals and birds, were undergoing a major radiation. Fossil material provides the major evidence of these evolutionary events and extinctions. Despite an unprecedented increase in our knowledge of Cretaceous biotas, there are still many temporal and geographical gaps in the record. The description of new fossil vertebrates in this Special Paper, including snakes, sharks, lizards, crocodiles and dinosaurs, directly addresses this problem in that many of them come from poorly known intervals such as the upper Lower and lower Upper Cretaceous, or previously poorly represented regions such as Madagascar and Japan.