Georges Cuvier (1769-1832) was one of the most outstanding scientific ‘savants’ of his time. His work on comparative anatomy was dramatically deepened by his study of the bones of fossil mammals and reptiles, many of which he showed were distinct from those of any living species, thereby claiming a major role for extinction in the history of life on Earth. In 1800 he wrote a preliminary report on his research, appealing to others around the world to contribute to it by sending him accurate images of further fossil bones. This appeal was highly successful, and illustrates the character of the international scientific community at the start of the 19th century. Cuvier’s prospectus, given here in English translation, is a landmark of pivotal significance in the history of the Earth sciences.