The d’Orbignys and their molluscs

During a career of less than 30 years, French 19^th century scholar Alcide d’Orbigny became one of the most prolific malacologists of all times. He named more than 5,000 new mollusc taxa, including 92 genera and 16 families. His numerous large, influential works include the ‘Histoire naturelle, générale et particulière des céphalopodes’ (with André de Férussac), the (unfinished) ‘Paléontologie française’ and the ‘Cours élémentaire de paléontologie’, which, besides their taxonomic and systematic achievements, helped establishing biostratigraphy as a science and laying the foundations of the geological timescale. His father and brother, Charles Marie and Charles Henry d’Orbigny, also studied molluscs, but described less than a dozen new species each. We assessed the malacological contributions of the three d’Orbignys and, listing all the new names, for the first time reveal the actual magnitude of Alcide’s malacological work. For each species, information on type localities, type ages, type material and, where possible, the latest scientific opinion has been established. Precise publication dates were researched, and numerous nomenclatorial issues clarified. Alcide d’Orbigny coined hundreds of replacement names for junior homonyms, thus contributing greatly to a stable nomenclature. The resulting data can be analysed in various ways, showing the impact of Alcide’s research. For example, more than 60% of the new mollusc species he described are Mesozoic, while only 15% are Recent. A remarkably high number of genus- and species-level names coined by the d’Orbignys are still valid, and many of them represent type species or genera of valid genus- or family-level taxa. Thus, while Alcide d’Orbigny’s work has not been received without criticism by his peers, it has aged well and remains a source of inspiration for further studies. Without the seminal contributions of taxonomists like Alcide d’Orbigny, today’s palaeobiological research would be unthinkable.