The holotype of Pachycormus macropterus (Blainville, 1818), type species of the genus Pachycormus Agassiz, 1833, is the earliest articulated fossil of a bony fish (Osteichthyes) found in France that was mentioned and figured in a publication. This specimen, long regarded as a petrified salmon, was discovered in 1747 in Grandmont, at about 10 miles north-west of Beaune (department of Côte-d’Or, Burgundy), where Toarcian deposits are exposed. The lord of the place, Pierre-Philibert Gillet de Grandmont (1705-1767), took possession of the fossil. It was exhibited in his cabinet in Beaune where it was studied by Abbot Antoine Gandelot (1714-1785). The fossil collector Claude Varenne de Béost (1722-1788), who was interested in the mineral resources of Burgundy, drew a picture of the fish that was engraved in Dezallier d’Argenville’s Oryctology published in 1755. Unpublished documents belonging to the Countess of Rochechouart (1711-1779) show that several fossil collectors, such as the Spanish Pedro Franco Dávila (1711-1786), tried in vain to acquire the fossil. Gillet de Grandmont was asking the excessive amount of about 3000 livres (c. 32.3 lb of silver) in the French currency of that time. After his death in 1767, the fish was finally bought between 300 and 400 livres by Georges-Louis Leclerc, Count of Buffon (1707-1788), for the King’s Cabinet, which formed the nucleus of the Muséum national d’Histoire naturelle, formally established in 1793. This specimen, one of the very few fossils from the King’s Cabinet still preserved today, was studied in the early nineteenth century by Barthélémy Faujas de Saint-Fond, Henri Marie Ducrotay de Blainville and Louis Agassiz.