Vertebres agnathes du Devonien inferieur de l'Artois (Pas-de-Calais, France) : implications biostratigraphiques
Blieck, A.; Janvier, P.
Annales de Paleontologie 753: 125-167
The Upper Upper Silurian-Lower Devonian series of Artois (Pas-de-Calais, northern France) have yielded, from outcrops, borings and coal-shafts, several vertebrate-horizons. We describe here new specimens of agnathans (Heterostraci: Poraspis barroisi, P. sp., Protopteraspis gosseleti, Pteraspis rostrata, Rhinopteraspis dunensis, Pteraspid. indet;Osteostraci:Pattenaspis artesensis nov. sp.). They have been collected in Vimy 1 bis, and Lievin 6 and 7 coal shafts, in the Vincly Wood and the Pernes Quarry. They lead to the vertebrate-zonation of the Lievin Group (Pridoli-Lochkovian) and the Matringhem-Vincly Sandstones (Pragian-Emsian). A revision of the vertebrate-zonation of the Lower Old Red Sandstones (Uppermost Downton Group-Ditton Group) of the Welsh Borderland is also proposed and correlated to the Lievin Group zonation. In this connectiona we define a new biozone, the Pteraspis rostrata zone. Finally we also discuss correlation with the Lower Devonian of Ardenne (Belgium).