Sprecher
Beschreibung
Eleven sedimentary rock samples of the upper 15 m of the Rio da Batateira Formation from the Cascata section (sensu Heimhofer and Hochuli, 2010) have been investigated investigated using routine application of SEM on pollen. The sampled section comprises fluvial to deltaic sedimentary rocks of Aptian age. Up to now, 22 eudicot pollen could have been identified, such as Trisectoris reticulatus together with numerous small-sized and large-sized Tricolpopollenites- and Retitrescolpites types. Particularly, when the pollen grains are small (<20 µm), the application of SEM facilitates the differentiation of pollen ektexines of pollen that looks similar (e.g., “scabrate”, “reticulate”) when using solely LM. High magnification of SEM demonstrates that ektexines can be striate, striato-reticulate, rugulate, coarsely to finely reticulate, homobrochate, heterobrochate, having brochi with or without free standing columellae, muri with long or short columellae, tectate foveolate or perforate, or semitectate with supratectal ornamentation or without ornamentation, thus displaying a high variety of pollen wall sculpture and ornamentation. The results of the high resolution SEM investigation of the Rio da Batateira sedimentary rocks show that the NW Brazil was one of the localities that witnessed an early diversification phase of angiosperms in the northern Gondwana realm.