Resumen de Some Late Cretaceous and Early Tertiary Pteridophytic spores from the Southern Nigeria sedimentary basin
Pteridophytic spore assemblage of the Late Cretaceous (? Campanian-Maastrichtian) and Early Tertiary (Paleocene-Eocene) of southern Nigeria, shows a preponderance of laevigate trilete and monolete spores comparable to those of modern families of Cyatheaceae and Polypodiaceae, as well as few others comparable with modern families of Gleicheniaceae, Schizeaceae and ?Lycopodiaceae. Laevigate monolete and trilete spores are more abundant, but less diverse, whilst the sculptured forms of these are few in the spore assemblage. It is considered that the latter forms were produced by plants that are probably insignificant in the floral composition at these times, or other factors of distribution were responsible for their paucity. Associated pollen grains compare sculpturally and structurally with extant pollen attributed to the swamp or marginal environment of deposition, by previous other workers. Presence of sometimes, numerically high, but less diverse organic-walled microplankton at some horizons, suggests that the local environment of deposition was periodically inundated by marine water, probably during eustatic changes in sea level.
