RESUMO -Pecopteris pedrasica e Asterotheca piatnitzkyi tiveram aqui suas diagnoses emendadas a fim de abranger a polimorfia de suas frondes e esclarecer as ambigüidades na classificação taxonômica das mesmas. Da análise desta polimorfia, foi possível estabelecer um modelo de desenvolvimento para estas frondes, em que a diferenciação ocorre segundo um gradiente topológico das porções proximais para as distais e das porções basiscópicas para as acroscópicas. Este modelo é de grande valia não só para o entendimento da ontogenia de frondes, mas também para a classificação de formas fósseis que porventura apresentem-se incompletas. Com a resolução taxonômica aqui empreendida, pode-se também estabelecer uma correlação mais efetiva entre as distintas associações pecopterídeas da América do Sul. Esta mesma resolução, permitiu constatar que P. pedrasica é a pecopterídea de maior distribuição espacial e temporal do Neopaleozóico sul-americano. Esta distribuição confere um indiscutível caráter euritópico a P. pedrasica, uma vez que os ambientes e as variações climáticas enfrentadas por esta forma nas regiões habitadas ao longo do intervalo de tempo vivido, foram muito diversos. Palavras-chaves:Frondes polimórficas, Asterotheca piatnitzkyi, Pecopteris pedrasica, Permiano, América do Sul. ABSTRACT -REVIEW OF POLYMORPHIC PECOPTERIDS FROM SOUTH AMERICA NEOPALEOZOIC.Pecopteris pedrasica and Asterotheca piatnitzkyi diagnosis were emended here in order to involve their polymorphic nature and to resolve their present taxonomic ambiguity. A model for frond development was established from analysis of that polymorphy where the differentiation occur according to a topologic gradient from proximal and basiscopic to distal and acroscopic portions. This model is useful both to the frond ontogeny understanding and the classification of those putative incomplete forms. The distinct South American pecopterid associations could be more closely correlated by the taxonomic resolution here proposed. This resolution permitted concludes that P. pedrasica is the pecopterid with the broadest spatial and temporal South America Neopaleozoic distribution. This distribution provides an indisputable eurytopic nature to P. pedrasica inasmuch the environment and climatic changes endured for this form have been too diversified.

Fossil plants belonging to the morphogenera Glossopteris, Pecopteris and Asterotheca were collected from the upper part of the Chutani Formation (Titicaca Group), near the town of San Pablo de Tiquina, on the southeastern shore of Lake Titicaca (northern Altiplano, Bolivia). Here we report the analysis of fern-type foliage found at this location. Three species of pecopterid fronds are identified: Pecopteris dolianitii Rohn and Rösler, P. cf. P. cadeadensis Rohn and Rösler, and P. cf. P. pedrasica Read. All these species are typically found in Permian deposits of the Paraná Basin in southern Brazil. Despite the poor preservation of the material, a fertile specimen could be studied and was determined as Asterotheca sp. The paleoenvironmental and paleoecological implications of this new find are briefly analyzed.

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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...

The site of Morro do Papaléo in Mariana Pimentel town is one of the best outcrops of Rio Grande do Sul State, southern Brazil, both in terms of diversity and abundance of fossils plants. The record of plants with frond-like foliage for Permian strata of the Rio Bonito Formation (Paraná Basin) in the Rio Grande do Sul State has been restricted to few specimens of the morphogenera Eupecopteris and Sphenopteris. Recent collectings in the uppermost part of Morro do Papaléo outcrop have revealed new kinds of pecopterids fronds, i.e. Asterotheca and Pecopteris, both inedita in the state. This work describe and classify these pecopterids fronds. The stratigraphic and paleoenvironmental implications resulting from record of these new taxa are briefly discussed.