The main objective of my research is to determine the floristic composition (abundance and diversity) of several tropical sites (Colombia, Peru and Brazil) through the use of quantitative palynology. With this information I will be able to determine floristic patterns of different plant groups in the tropics and infer major climatic conditions of tropical latitudes during the early radiation of flowering plants (using abundance of climate indicator species). The next step is to determine how the floristic composition of tropical latitudes compares to the composition of ecosystems in high latitudes and test the presence of a latitudinal diversity gradient for different plants groups during the Lower Cretaceous.