A North American ammonite fauna from the late Middle Turonian of Vaucluse and Gard, southern France: the Romaniceras mexicanum, Prionocyclus hyatti and Coilopoceras cf. springeri association

Abstract

An unusual, exotic, ammonite fauna including Romaniceras mexicanum Jones, 1938, Prionocyclus hyatti (Stanton, 1894) and Coilopoceras cf. springeri Hyatt, 1903 is recorded from the late Middle Turonian of Vaucluse and Gard, southern France. It is the first record of this ammonite association outside the Gulf Coast region and the Western Interior of the United States of North America. Up to present, these species were considered as endemic to the Western Interior sea-way. The migration of numerous ammonites from North America to western Europe during the late Middle Turonian suggests it is linked to a transgressive event or to a short sea-level high.