Paleoecological and paleogeographical characterization of Portalites Hemer & Nygreen, 1967 in the Gondwanan record

Abstract

Portalites is a genus characterized by circular spores with a functional pore and a smooth or ornamented surface, which can be attributed to the kingdom Fungi. The species involved are abundantly found in palynological preparations of interglacial and post-glacial deposits from Carboniferous and Permian of Gondwana, but they are also found locally up to the Triassic. The genus includes five species: Portalites confertus (type species), P. gondwanensis, P. baculus, P. niger, and P. rigidus. Materials derived from the Amazonas (Monte Alegre Formation) and the Paraná basins (Itararé Group and Rio Bonito Formation) in Brazil, ranging from the Pennsylvanian to the Cisuralian, were directly analyzed to understand the association of Portalites with the local flora. We observed that the studied species are primarily associated with Lycopsida and Filicopsida. Through the integration of lithological data, we identified that Portalites predominantly occurs in fine-grained sediments, indicative of low-energy, humid environments, and in proximity to freshwater or brackish conditions. In terms of paleogeography, the species exhibits its widest distribution in the Gondwana basins during the Pennsylvanian and Cisuralian.