The Bajocian Stage takes its name from the
Latin name (Bajocae) of the town of
Bayeux, in the region of
Normandy in
France. The stage was named and introduced in scientific literature by French palaeontologist
Alcide d'Orbigny in 1842. The base of the Bajocian stage is defined as the place in the stratigraphic column where
fossils of the
ammonite genus Hyperlioceras first appear. A global reference profile (a
GSSP) for the base is located at
Murtinheira, close to
Cabo Mondego in
Portugal. The top of the Bajocian (the base of the Bathonian) is at the first appearance of ammonite species
Parkinsonia convergens.
Subdivision The Bajocian is often divided into Lower/Early and Upper/Late subages or substages. In the
Tethys domain, the Bajocian contains seven ammonite
biozones: • zone of
Parkinsonia parkinsoni • zone of
Garantiana garantiana • zone of
Strenoceras niortense • zone of
Stephanoceras humphriesianum • zone of
Sonninia propinquans • zone of
Witchellia laeviuscula • zone of
Hyperlioceras discites == References ==