Occurrence of Glossopteris browniana Brongniart in the upper levels of Quitéria outcrop (Rio Bonito Formation, Paraná Basin), Rio Grande do Sul State, Brazil (Lower Permian)

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 Quitéria 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 Paraná Basin. The identification of this species improves upon the regional plant stratigraphic framework, as well as the knowledge about Quitéria 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, Quitéria Outcrop, Rio Bonito Formation, Paraná Basin, Brazil.