On some Ordovician Fossils from Northern Argentina

Abstract

The list of fossils described in this paper and their stratigraphical distribution is shown in the Table on p. 122. The Kainella and Leiostegium zones of the Quebrada del Toro are the equivalent of the Late Ozarkian of Western North America. The fauna of the arenaceous-calcareous beds of the marine-glacial deposits of the Saladillo group is not characteristic enough to enable an exact determination of the age. Nevertheless, from the stratigraphical position of these beds, they could be considered as indicating Upper Beekmantown age. The lower part of the Parcha group, with the single determinable fossil Basilicoides taurinus gen. et sp. nov. has been provisionally referred to the Llandeilian. The faunule of the Asaphellus zone of the Quebrada de Chalala shows affinities with part of the Tremadocian of England, the Tomkolian of South Chosen, and the upper zones of the “ Ceratopygeregion ” of Scandinavia. The stratigraphical relationship between the Kainella and Leiostegium zones of the pre-Puna and the Asaphellus zone of Purmamarca is not known.