Revaluation of the Glossopterids from the Lower Permian of Cambaí Grande Outcrop, Paraná Basin, RS

Abstract

The Cambaí Grande Outcrop, located in the municipality of São Gabriel of the State of Rio Grande do Sul, southernmost Brazil, is characterized by the occurrence of an exclusive fossil assemblage composed of marine invertebrate shells associated with some plant remains of elements from the “Glossopteris Flora”. The main goal of this work is to reevaluate the “Cambaí Grande Flora” as well as section reanalysis. Therefore, the authors reviewed the existing paleobotanical material deposited at Universidade Federal do Rio Grande do Sul (UFRGS) and Universidade do Vale do Rio dos Sinos (UNISINOS) and redescribed the outcrop section. The outcrop sequence is 60 m thick and is divided into two well defined sections (both upper and lower). The studied plants were found in the basal part of the upper section. Besides the paleobotanical contents like Gangamopteris, Samaropsis, Cordaicarpus, Cordaites, unidentified remains of algal filaments and a cone of gymnosperm previously recorded by several authors and not properly understood thus far have been analyzed. This study confirmed for the first time the presence of Glossopteris-type leaves and the Indian species Gangamopteris cyclopteroides Feistmantel in the Cambaí Grande flora which increases the possibility of a correlation of this plant assemblage with that of the Rio Bonito Formation, Brazil, and those of the younger horizons of India.