Cretaceous–Lower Paleogene ostracods from the Pelotas Basin, Brazil

Abstract

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

New genera and species of Ostracoda from the Maastrichtian and Danian of the Neuquén Basin, Argentina

“…4 from the Paleocene of the Pelotas Basin (Ceolin et al . ) in mainly by being more inflated in dorsal view and larger overall.…”

Ostracoda and foraminifera from Paleocene (Olinda well), Paraíba Basin, Brazilian Northeast

“…Occurrence Apostolescu 1961, Reyment 1963, Foster et al 1983, Okosun 1987, Carbonnel et al 1990, Sarr 1999 and South America (e.g., Bertels 1973, Ceolin et al 2011). This species differs from others by its rounded posterior outline and strong anteromarginal rib clearly seen in dorsal view.…”

Biochronostratigraphy and paleoenvironment analysis of Neogene deposits from the Pelotas Basin (well 2-TG-96-RS), Southernmost Brazil

“…Contributions derived from benthic foraminifera and ostracods of the pre-Quaternary sucession are relatively abundant, providing paleoenvironmental MICROPALEONTOLOGY AND ISOTOPES, NEOGENE, PELOTAS BASIN interpretations (e.g., Koutsoukos 1982, Carreño et al 1999, Ceolin et al 2011). Simões et al (2008 presented a taxonomy review of brachiopods recorded from some Neogene deposits of the onshore portion.…”