Cretaceous–Lower Paleogene ostracods from the Pelotas Basin, Brazil

摘要: A total of 479 samples from five drill-holes the Pelotas Basin were analysed. Despite huge number samples, only 98 specimens recovered, belonging to nine families, 21 genera and 34 species (most in open nomenclature). Due paucity poor preservation this material, just seven taxa identified or tentatively at level: Cytherella cf. C. araucana Bertels, Cytherelloidea spirocostata Bairdoppilata triangulata Edwards, Actinocythereis indigena Brachycythere gr. sapucariensis Krommelbein, Wichmannella Bertels meridionalis Bertels. Four could not even be generic level are referred as “gen. et sp. indet.”. Trachyleberididae Cytherellidae most diversified abundant families while Paracypris genera, with four species, respectively. The K–Pg boundary is marked by a faunal change local disappearance Cytherelloidea, Argilloecia, Cythereis, Brachycythere, Pondoina Rostrocytheridea, first occurrence Neonesidea?, Bairdoppilata, Ambocythere, Buntonia, Langiella?, Trachyleberis Krithe. Cytherella, Paracypris, recorded Cretaceous well Paleogene. This study suggests neritic marine environment for analysed interval.