Abstract The objectives of this study were the biostratigraphic and paleobiogeographic interpretations of the calcareous nannofossil records of the Romualdo Formation (Aptian-Albian) in the south-central portion of the Araripe Basin. The methods used to process the samples were decanting. smear slide. centrifugation. https://www.alarecre.com/American-Flag-Color-Block-iPhone-14-Waterproof-Case-p12619/