Biostratigraphy

Abstract

Neoproterozoic stromatolites were first recognised in the Río de la Plata Craton (RPC) by González Bonorino (1954) in the Sierras Bayas Group (Argentina). The first body fossils were also described from this unit by Fairchild (1978) and Pothe de Baldis et al. (1983), consisting of organic-walled microfossils (acritarchs). In Uruguay, Montaña and Sprechmann (1993) were the first to recognise Cambrian stromatolites in the Cerro Victoria Formation. The first report of Neoproterozoic body fossils (acritarchs) in Uruguay is due to Gaucher and Schipilov (1994) and Gaucher et al. (1996). Since these first reports, around a dozen papers appeared that deal with Neoproterozoic and Cambrian fossils in the RPC. The sedimentary successions deposited on and around the RPC record the existence of a diversified biota in Ediacaran times, including cyanobacteria, acritarchs, shelly fossils, stromatolites, trace fossils and –possibly- rare members of the Ediacara fauna.