The new genus Vanneauina belonging to the family Orbitolinidae is described herein from Lower Cretaceous shallow-water carbonates of southeastern France. Its type-species, here referred to as Vanneauina vercorii (Arnaud-Vanneau, 1980) comb. nov., has been described originally as belonging with some reservations to Dictyoconus Blanckenhorn. Vanneauina gen. nov. differs from Dicytoconus above all by its simple exoskeleton (lacking rafters), triangular-shaped primary beams, pillars laterally fusing at the base and top, and a simple and slightly eccentric embryo. So far, Vanneauina is a monospecific genus. In its type-area, it is reported from the lowermost Barremian (upper part of the hugii zone) to the lower Aptian (lower part of the weissi zone). After the present taxonomic revision, there is no representative of Dictyoconus in the orbitolinid assemblages from the upper Hauterivian to lower Aptian interval in the Urgonian type area of southeastern France and Switzerland. |
