Gondwana monosaccate pollen grains: palynotaxonomical and stratigraphic approach based on selected genera of Brazilian intracratonic basins

MOREIRA FÉLIX, C., SOUZA, P.A., DI PASQUO, M.M.

Bonn

Congreso; 12th International Palynological Congress (IPC-XII) and 8th International Organisation of Palaeobotany Conference (IOPC-VIII); 2008

Institut für Paläontologie, Universität Bonn

The Subturma Monosaccites Chitaley emend. Potonié & Kremp includes a significant number of species of monosaccate pollen grains well represented in the Late Palaeozoic Gondwanan palynofloras related to the Cordaitales, Pteridospermales and Coniferales. In the last decades, some taxononomical revisions were published based on South America materials, especially  from Argentinian and Brazilian basins. Pennsylvanian and Permian deposits in Brazil yielded abundant records of these pollen grains enough to promote a re-examination mainly of several species of genera here assigned to the Infraturma Monopolsacciti (e.g., Costatascyclus Felix & Burbridge emend. Urban) and Dipolsacciti (e.g., Cannanoropollis Potonié & Sah, Plicatipollenites Lele, Potonieisporites (Bhardwaj) Bharadwaj, Circumplicatipollis Ottone & Azcuy, Caheniasaccites Bose & Kar, Crucisaccites Lele & Maithy, Stellapollenites Lele and Divarisaccus Venkatachala & Kar). New palynofloras obtained from the Upper Palaeozoic deposits of Brazilian intracratonic basins allow the updating of synonymy lists of many species recorded in other basins of Uruguay and Argentina also. Their main diagnostic features are emphasized and schematic drawings are provided to make comparisons easier. Moreover, these palynofloras  have recently been well constrained by radiometric data, so they are used to refine the stratigraphic distribution of this group, which is more abundant in the Pennsylvanian and Lower Permian deposits, and is scarce or absent from the Middle to the Upper Permian in this part of Gondwana.