Les heterostracés (vertébrés, agnathes) du Dévonien inférieur du nord de la France et du sud de la Belgique (Artois-Ardenne)

35 localities from the Lower Devonian of Artois-Ardenne have yielded heterostracans or only traces of heterostracans. These localities are reviewed and the revision of the specimens leads to a vertical zonation from the Upper Lower Gedinnian up to the Emsian. The faunal assemblages are then placed in the L. Devonian palaeogeography, along the shore of the Brabant Massif of North-Atlantis.