South American marine Silurian communities

BOUCOT, A.J.; BENEDETTO, J.L.; YNGVE GRAHN, J.H.; MELO, G.; SÁNCHEZ, T.M.; WAISFELD, B.G.

Paleocommunities: A case study from the Silurian and Lower Devonian

Cambridge University Press

Lugar: Cambridge; Año: 1999; p. 841 - 849

The South American Silurian may be divided up into two parts, that belonging to the Malvinokaffric Silurian, and that of the typical North Silurian Realm, North Atlantic region European Province aspect, with the latter known essentially only from the Mserida Andes of Venezuela to the South Lake Maracaibo. This simple paleogeographic picture, however, becomes more complex as new paleontological and sedimentological information becomes available. Typical Malvinokaffric faunas are found in the cratonic areas (Paraguay, Brazil) during the Llandovery while pure North Silurian Realm faunas are recorded only in northern South America (Venezuela). But in the areas perpheral to the cratons, the Andean region shows mixed assemblages containing typical Mlavinokaffric taxa (Clarkeia, Heterorthella) associated with North Silurian genera (Leangella, Plectodonta, Coelospira). This complexity may be due to several factors such as aleogeographic position of the basins, connections between them and the open ocean, the oceanic circulatin pattern, and local envirnmental conditions.