Presença de Glossopteris browniana Brongniart em níveis do topo do afloramento Quitéria (Formação Rio Bonito), Rio Grande do Sul, Brasil (Permiano Inferior)

Abstract

New paleobotanic material recovered in the Rio Grande do Sul State, southernmost Brazil, allowed to the identification of Glossopteris browniana Brongniart for the first time in the upper levels of Quiteria outcrop. In this way, the stratigraphic range of this species is extended up to the Subzona Botrychiopsis valida . G. browniana is here considered to be restricted to the upper levels of Rio Bonito Formation, recently considered as being deposited in a Sakmarian – late Artinskian interval, and a guide-species of the uppermost plant zones from Rio Grande do Sul State and southern areas of Parana Basin. The identification of this species improves upon the regional plant stratigraphic framework, as well as the knowledge about Quiteria outcrop taphoflora. The presence of a shoot with attached leaves indicates a leaf polymorphism to the species, also previously mentioned by several authors. Their distinct leaf physiognomy confirms that the venation pattern is the more diagnostic feature in the identification of G. browniana . Key words: Glossopteris browniana , Lower Permian, Quiteria Outcrop, Rio Bonito Formation, Parana Basin, Brazil.