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This work presents a taxonomic, biostratigraphic and paleoecological study of planktic foraminifera recovered from

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-Eleven wells (1,765 cutting samples) from the Senonian of Santos Basin were examined, with the record of both marine and mixohaline ostracode faunas. The latter are composed mainly by Fossocytheridea and characterized by medium specific richness and high abundance. Four new species are here described: F. posterodentata, F. ventrotuberculata, F. santosensis and F. anfisulcata and another one is left in open nomenclature. Besides the conspicuous variability, F. ventrotuberculata sp. nov. is the first species described for the genus with valve reversal. The significance of these new species described and their potential for applied approaches are discussed.Key words: Fossocytheridea, Ostracoda, taxonomy, Brazil, Santos Basin.RESUMO -Onze poços (1.765 amostras de calha) do Senoniano da bacia de Santos foram estudados, registrando faunas de ostracodes marinhas e mixoalinas. Estas são compostas basicamente por Fossocytheridea e caracterizadas pela riqueza específica baixa e alta abundância. Quatro novas espécies são aqui descritas: F. posterodentata, F. ventrotuberculata, F. santosensis e F. anfisulcata, e outra é deixada em nomenclatura aberta. Além da notável variabilidade, F. ventrotuberculata sp. nov. é a primeira espécie descrita para o gênero com reversão de valvas. A importância destas novas espécies descritas e seu potencial para estudos aplicados são discutidos. Palavras INTRODUCTIONThe first researches on Cretaceous ostracodes from Santos Basin were done by Benson (1977) and Miller et al. (2002). More detailed taxonomic work began with the description and ecological characterization of the species Afrocytheridea? cretacea and Pelecocythere dinglei by Piovesan et al. (2010).One of the most remarkable consequences of the scarcity of taxonomic knowledge is the limitation it imposes on paleoceanographical and biostratigraphical uses. Ostracodes are the most abundant calcareous microfossil in the Upper Cretaceous paralic deposits of Santos Basin. Considering that this basin was strongly affected by sea-level changes, ostracode populations were influenced accordingly, under conditions favorable for speciation. These faunas are dominated by cytherideids, Fossocytheridea Swain & Brown being the most common genus.The first record of Fossocytheridea in Brazil was by Viviers et al. (2000) in the Campanian of Potiguar Basin, as Sarlatina Babinot & Colin, which is now considered its junior synonym (Tibert et al., 2003). In the latter article, some species of Fabanella Martin, Ovocytheridea Grekoff, Dolocytheridea Triebel, Antibythocypris Jennings and Cytheridea Bosquet, were also reassigned to Fossocytheridea. In other Cretaceous deposits (e.g. Western Interior Basin, USA: Swain & Brown, 1964, Tibert et al., 2003, 2009 West Africa, Mali: Colin et al., 1996) assemblages with Fossocytheridea are interpreted as indicators for marginal-marine environments. The ecological classification of brackish-water environments into oligohaline, mesoahaline and polyhaline used herein follows Belt et al. (2005).The main obje...

Biostratigraphic results obtained with a systematic study of the planktic foraminiferal assemblages recovered from Upper Cretaceous-Lower Paleogene strata (Turonian? to early Danian in age) of Deep Sea Drilling Program (DSDP) Site 356, São Paulo Plateau, are presented and discussed herein. Fifty-nine planktic foraminiferal species were identifi ed within the studied interval, enabling the identifi cation of 11 planktic foraminiferal zones (Turonian? to early Danian in age): Marginotruncana schneegansi, Dicarinella concavata, Dicarinella asymetrica, Globotruncanita elevata, Contusotruncana plummerae, Radotruncana calcarata, Globotruncanella havanensis, Pseudoguembelina palpebra, Abathomphalus mayaroensis, Pseudoguembelina hariaensis and Pα. An unconformity spanning at least 0.96 Ma could also be suggested within core 31 (Maastrichtian in age), due to the absence of the Racemiguembelina fructicosa Interval Zone from the studied section. High sedimentation rates were estimated within the Santonian (Dicarinella asymentrica Total-range Zone) and the uppermost Maastrichtian (Pseudoguembelina hariaensis Interval Zone) of DSDP site 356, while lower and more constant values were suggested for the Campanian-lower Maastrichtian interval (Globotruncanita elevata Partial-range Zone to Pseudoguembelina palpebra Interval Zone). The reliability in identifying the Contusotruncana plummerae Interval Zone (Campanian in age) in Cretaceous sections of the South Atlantic Ocean is confi rmed herein.

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.

Within the Cretaceous Period, the Aptian-Albian interval (125–99.6 Ma, Ogg et al., 2008) was a critical time on a global scale. This is evident from 1) changes in the nature of the ocean-climate system brought about by increased ocean crust production coupled with active midplate and plate margin volcanism in a shifting paleogeography (Skelton et al., 2003); 2) cyclic deposition and preservation of common “black shales”, some of them termed Oceanic Anoxic Events(OAE1a to OAE1d) (Schlanger and Jenkyns, 1976; Arthur et al., 1990); 3) periodic changes in redox conditions at the ocean bottom (Oceanic Red Beds, ORBs) (Wang et al., 2009); and 4) rapid biotic radiations and turnovers (Leckie et al., 2002). The Aptian-Albian time is also of interest for one of the most noteworthy geomagnetic events, namely the post-M0r “Cretaceous Quiet Zone”. This long and constant normal polarity superchron without any convincing true reversal to date (Satolli et al., 2008) precludes usage of reversals magnetostratigraphy from the Aptian through the Santonian. The Poggio le Guaine core was designed to provide a high-resolution age model and a high-resolution relative magnetic paleointensity reference curve for the Aptian-Albian interval of the long normal Cretaceous superchron; it was also designed to understand the causal linkages among geological, biogeochemical, oceanographic and climatic eventsas well as their consequences. The core was drilled at Poggio le Guaine, where the most continuous, complete, and best preserved Aptian-Albian succession is exposed throughout the Umbria-Marche Basin (UMB) of the northern Apennines of central Italy (Fig. 1). It represents a continuous record of fossiliferous pelagic rocks extending from the Albian-Cenomanian boundary down to the uppermost Barremian (99.6–126 Ma). In this progress report we present the first preliminary findings of this ongoing project