During the last ZO years great progress has been achieved in our understanding of both earth history and vertebrate evolution. The result is that climatic/tectonic events in earth history can now be placed in a more precise and global time frame, that permit their evaluation as abiotic causal factors which might trigger extinction and dispersal events in vertebrate history. Great strides have also been made in genetics and cell biology, providing new insight into phylogenetic relationships among many vertebrates. These new data, along with data on chronologie resolution of earth history, provide tests of previous interpretations regarding ancestral-descendant relationships based solely on the fossil record. It is fitting and proper that a volume on European Neogene mammal chronology is produced at this time, to ensure that new interpretations of vertebrate evolution and chronology are based on the most accurate and current data. Vertebrate paleon­ tologists believe that the fossil record is the only secure data for measuring the actual course and tempo of vertebrate evolution. Knowledge of the fossil record must keep pace with advances in other areas of science so that inferences on vertebrate evolu­ tion are accurate and meaningful.