Upper Precambrian–Lower Cambrian biota from the northwest of Argentina

Abstract

Abstract The principal characters of the biota from Upper Precambrian–Lower Cambrian rocks in the northwest of Argentina are described. It is possible to observe two groups: the trace fossils and the medusoid impressions. At the same time, a regional palaeogeographical analysis is attempted as well as a comparison with outcrops of similar age from the Gondwanaland area and from North America.