Miospores from upper cretaceous‐Paleocene strata in northwestern Bolivia

Abstract

Outcrop samples from the Flora and Eslabón formations from northwestern Bolivia contain abundant terrestrial palynomorphs. Pollen grains and spores of 49 species belonging to 36 genera were identified and two new pollen species — Psilaperiporites boliviensis and Psilaperiporites suarezi — are described. The Bolivian palynoflora consists mainly of monocolpate, tricolpate and tricolporate angiosperm pollen grains. The gymno‐sperm pollen content is low and bisaccates are totally lacking. Some samples also include fungal spores and the fresh‐water algae Botryococcus. The assemblage from the Eslabón Formation is compared with that of the Proteacidites dehaani Zone, known from Colombia and Venezuela, and with that of the Tricornites elongatus Zone in Brazil, indicating late Maastrichtian age. The palynoflora of the Flora Formation is probably of Paleocene age. The results indicate deposition in a continental warm and humid environment, as suggested by the composition of the palynoflora which show an abundance of palm pollen grains and the presence of Botryococcus and Azolla megaspores.