Biostratigraphic and Paleogeographic relations of the Late Paleozoic marinestrata in the South American Gondwana

Abstract

Biostratigraphic and Paleogeographic relations of the Late Paleozoic marinestrata in the South American Gondwana?. The paleobiogeographic pattern of Late Paleozoic marine faunas in South America shows a distribution in three main realms. Two of them, at present time located to the east of the southern Andes, belong to the Gondwana province; they are the central gondwanic realm and the perigondwanic realm. An extragondwanic realm, showing tetian-like affinities, is located to the west of the Andean belt.

Faunas from the extragondwanic ?warm? facies were contemporary to those of the perigondwanic "cold" facies. In spite of their remarkable contrasting general features , faunal assemblages in both realms bear several taxa in common, revealing that some relationships existed between them. Rather than suspected terranes, this suggests that both realms were not far away, but separated by an arm of sea, which acted as a paleoclimatic barrier only to some groups of invertebrates.