The paleobiota of the Sanfranciscana Basin in the lower cretaceous and the paleodrainage of the Sao Francisco River

The breakup of the supercontinent Pangaea in the Middle Jurassic and the subsequent breakup of Gondwana with the formation of the South Atlantic Ocean, were two of the most prominent paleogeographic events of the Phanerozoic. Acting as a major obstacle for the Gondwanan rift propagation, the Congo-Sao Francisco Craton was an ancient and one of the most stable regions on the Eastern/Central South America and Africa. Based on paleontological and on paleogeographical data, the present manuscript discusses how the main drainage of the Sao Francisco Craton connected both northeastern marginal and the central intracratonic Brazilian regions as it does nowadays. It also deals with the history of one of the oldest and most resilient South American drainages during the transitional phase of the Gondwanan breakup. Based on the occurrence of fishes, ostracods, palynomorphs, and aquatic plants, the results presented herein suggest the existence of a previous drainage interconnecting the marginal and interior rift-related basins in a time anterior to the Aptian/Albian transgressions.