The line from Mézidon opened in 1879 and extended to Houlgate in 1882.
The first section was built between Dives-sur-Mer and Houlgate in 1882 as an extension of a railway line from Mézidon-Canon on the main railway line between Paris and Caen.
MNHN 1920-7 was found by local collector Dutacq in rocks thought to be Oxfordian (Upper Jurassic), of the Vaches Noires cliffs near Dives in Normandy, France, and was after being reported by amateur geologist Cazenave in 1920 acquired by Professor Marcellin Boule for the Muséum national d'histoire naturelle.