Rufloria Meyen em Sedimentos gondwanicos sulriograndenses (Formação Rio Bonito, Super Grupo Tubarão)

Resumo

The present research is an analysis of Cordaitanthales leaves from “Tonstein” associated to a coal seam in Jazida do Faxinal (Rio Bonito Formation, State of Rio Grande do Sul, Brazil). taphocenosis preserved as coalified compression, is primarily composed of foliar organs, with a predominance of Glossopteridales (Glossopteris brasiliensis Guerra-Sommer, Glossopteris similis-intermittens Guerra-Sommer, Glossopteris papillosa Guerra-Sommer, Glossopteris rio-grandensis Guerra-Sommer). There are very few isolated reproductive structures (Plumsteadia sennes Rigby) and seeds (Platycardia sp.). Fragments os sterile fronds, characterized as PTERIDOPHYLLA (Sensu BOREAU & DOUBINGER, 1975), corresponding exclusively to Sphenopteris type (Sphenopteris cf. Sph. Ischavonensis, Sphenopteris sp.), are very seldom represented. Leaves of Cordaitanthales are very important elements, belonging to only one species, Rufloria gondwanensis n. sp. The evidence that the Cordaitanthales found in the association are related, because of their epidermic patterns, to Rufloria Meyen, the typical Angara form, led to some hypothesis. Migration is considere to be the most plausible reason for the presence of this form in the association. This hypothesis is supported by paleographic maps (SMITH et al., 1981) which show, in the Permian, a continental alignment that would render migration possible.