Format: ORAL

Mnica R. Carvalho1, Fabiany Herrera2, L. Alejandro Giraldo3, Brielle Canares1, Laura M. Puente4, Carlos Jaramillo5

1 Museum of Paleontology and Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, USA 2 Negaunee Integrative Research Center, Field Museum, Chicago, USA 3 Department of Geosciences, The Pennsylvania State University, State College, USA 4 Departamento de Biología, Universidad Nacional de Colombia, Bogotá, Colombia 5 Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, Panamá

Neotropical plant communities are exceptionally diverse and are the result of dynamic processes that include diversification, dispersal, and local/regional extinctions driven by climatic fluctuations and tectonics over the past 66 million years. Two Paleocene floras from northern South America show the earliest evidence of angiosperm-dominated, closed-canopy forests that document the early stages in the evolution of Neotropical rainforests. The Cerrejn and Bogot paleofloras (5860 Ma) represent coastal and fluvial environments, respectively, and share similar climatic characteristics and family-level composition seen in living rainforests. Despite overall similarities and shared patterns of low plant richness, these fossil assemblages show contrasting ecologies and composition at sub-familial levels that reflect floristic heterogeneity at a regional scale by the Late Paleocene. Fossil species within dominant and species-rich plant families such as Fabaceae and Annonaceae are typically restricted to each flora, showcasing patterns of diversification in northern South America. This talk will revise recent findings within Paleocene floras of Colombia and evaluate the extent to which environmental gradients contributed to the early diversification of Neotropical rainforests.