Sprecher
Beschreibung
The Lusitanian Basin (western Portugal) comprises an extensive Cretaceous sequence with well-preserved plant fossils that provides a unique insight into the initial radiation of angiosperms during the Early Cretaceous. Several studies on leaf floras and plant mesofossils from the Portuguese sequence have been more systematically oriented, while palynological studies have to a large extend been devoted to stratigraphic aspects. The Early Cretaceous palynofloras from the Lusitanian Basin have yielded significant data that complement inferences from leaf and mesofossil floras providing important clues for the reconstruction of ancient ecosystems. In the present work, we report on preliminary results of palynological analyses from the Lower Cretaceous (Aptian/Albian) of Catefica, central-western Portugal. The Catefica strata consist of fluvial cross-bedded light-coloured sandstones with intercalated dark clay beds belonging to the Almargem Formation, considered to be of late Aptian – early Albian age. The palynoflora is rich and diverse, dominated by fern spores assigned to the families Anemiaceae, Cyatheaceae/Dicksoniaceae, Lygodiaceae and Osmundaceae, reflecting the existence of swamp pteridophyte vegetation. The occurrence of bryophytes and lycophytes representatives supports the existence of local humid conditions, in the alluvial plain. The presence of xerophytic components, represented by cheirolepidiaceous conifer pollen Classopollis together with bisaccate pollen grains, reflects the existence of conifer vegetation on upland and slopes. Angiosperms are also present, but subordinate. The most common angiosperm pollen is represented by reticulate grains of the Clavatipollenites-type. Furthermore, pantoporate pollen and different types of tricolpate pollen grains were recognised in the palynoflora.