Turonian ammonites from northwestern Aquitaine, France

The position of the Cenomanian-Turonian boundary is established for the first time in Charente-Maritime, northwestern Aquitaine (France), on the basis of ammonite occurrences and the δ13C isotope curve, corresponding to Oceanic Anoxic Event 2, that straddles the boundary. The earliest Turonian ammonites recognised are a monospecific occurrence of the early early Turonian pseudotissotiine Bageites bakui Zaborski, 1998, previously known only from northern Nigeria. Newly collected material and well-preserved specimens from existing collections supplement previous records, and include species of Placenticeras, Morrowites, Kamerunoceras, Romaniceras (Romaniceras), Spathites (Jeanrogericeras), Mammites, Fagesia, Neoptychites, Choffaticeras (Leoniceras), Collignoniceras and Lecointriceras. These confirm the presence of the upper lower Turonian nodosoides Zone and the lower middle Turonian turoniense and kallesi zones/subzones of authors.