From the preface:
"The present volume of Fossilium Catalogus slowly emerged from my work on the stratigraphy of the Valanginian and the Lower Hauterivian and evolved in the database Ammonite which was developed over the last ten years. During my work on ammonite stratigraphy I discovered the major diversity of ammonite literature: in many languages, from all parts of the world, often obscure, little known or entirely unknown. [...] Intention of this work is to give current and future researchers an overview, as complete as possible, of genera, species and types of Lower Cretaceous ammonites with the corresponding literature. This survey can be important as a tool for the work on the actual problems like the definition of the Jurassic-Cretaceous boundary, the definition of the boundaries between (sub)stages of the Lower Cretaceous and the definition of (sub)zones in the Lower Cretaceous."