Systématique et importance stratigraphique des Rhynchonelles du Calcaire de Crémenes (Dévonien superieur, province de León, Espagne)

In the present study some problems concerning the stratigraphy of the Upper Devonian in the southernmost strip of the Cantabrian Mountains (Province of León, Spain) are briefly discussed. This sequence consists of rather uniform and nearly unfossiliferous sandstones, divided by a hiatus of Lower Famennian age into two genitically different unities. An intercalated calcareous lens, the Crémenes Limestone, contains a very rich and attractive fauna. Three rhynchonelloid species, belonging to this limestone have been described: Cupularostrum cantabricum n. sp., Ptychomaletoechia cf. gonthieri (Gosselet, 1887) and „Camarotoechia” boloniensis (D’Orbigny, 1850). These determinations together with those presented by Comte (1959) may lead te the conclusion that the Crémenes Limestone is of lowermost Famennian age and is older than the stratigraphic hiatus.