La limite Lochkovien-Praguien (Dévonien inférieur) dans le Massif armoricain : espèces index et corrélations

The precise range of selected taxa among the conodonts, chitinozoans, brachiopods and trilobites occuring in the calcaro-argilaceous Eodevonian sequences of the Armorican Massif allows the accurate location of the Lochkovian-Pragian boundary by reference to the newly defined Bohemian stratotype. Moreover precise correlations are established with homologous sequences of eastern Celtiberian Chains, Sierra de Guadarrama and Cantabrian Mountains, in Spain where the Gedinnian-Siegenian boundary would be practically synchronous with the Lochkovian-Pragian boundary