| Abstract: | Investigations carried out on the argillaceouslacustrine sedimentary rocks interbedded with marine lower Thanetian (lower Eocene) in the sub-pyrenean basin of southern France allowed the discovery of a micro-molluscan fauna: Carychium (Carychium) munieriBriart & Cornet, Carychium (Carychiopsis) cairocurbum nov. sp. and Valvata (Cincinna) indecisaCossmann. C. munieri and V. indecisa are known also from the upper Montian (early lower Eocene) of Belgium.Bivariant and multivariant analysis of several populations of C. munieri seem to document the presence of two morphotypes in the Montian of Belgium, only one persisted into the upper Thanetian in southern France.In the belgian Montian, these faunas appearedwhen climate was becoming warm. |
