Offneria simplex nov. sp, (rudist, Caprinidae) from the Barremian of South-East France and Cuba. Implications for the biostratigraphy and the evolution of the genus Offneria

Offneria simplex, nov. sp. is described from the mid Barremian, Urgonian li mestones in the Vercors and Languedoc regions; it is also identified from C uba. This is the oldest representative, known hitherto, of the genus Offner ia, considered so far restricted to the early Aptian. This discovery provid es new insights on the species radiation and evolution of the genus, in a w ell defined stratigraphic context, and its relationships with Praecaprina. This genus is characterized by independant evolutionary rates for the two v alves. Its survivorship is about 4 Ma with a rate of species origination hi gher than 1 Ma. Offneria simplex nov. sp, has a relatively wide palaeobioge ographic distribution, from the Caribbean to western Europe and could be a biostratigraphic marker of the Barremian.