New oligocene cyprididae species (crustacea, ostracoda) from the tremembé formation, Taubaté Basin, Brazil, and their paleolimnological significance

Two new Oligocene ostracod species, Eucypris lobatoi sp. nov. and Potamocypris taubatensis sp. nov., are herein proposed. This is the first fossil record of these genera in Brazil, and the species identified occur in two distinct phases of the Tremembé Paleolake. It is assumed that Eucypris lobatoi sp. nov. has lived in the oldest and more stable phase of the lake, Potamocypris taubatensis sp. nov., in the youngest and more unstable phase. These data support a previous ostracod-based paleolimnological interpretation which sustains a shallowing trend in the paleolake during the final deposition of the Tremembé Formation.Duas novas espécies de ostracodes, Eucypris lobatoi sp. nov. e Potamocypris taubatensis sp. nov., são propostas neste trabalho. Este é o primeiro registro fóssil destes gêneros no Brasil, cujas espécies identificadas ocorrem em duas fases distintas do Paleolago Tremembé. Eucypris lobatoi sp. nov. ocorre durante a fase mais antiga e estável do paleolago, enquanto Potamocypris taubatensis sp. nov., na fase mais recente e instável. Estes dados corroboram uma interpretação paleolimnológica prévia baseada em ostracodes que sustenta uma tendência de raseamento do paleolago durante o final da deposição da Formação Tremembé

A Permian mixohaline ostracod association of the Teresina Formation, Paraná Basin, Brazil

New ostracod species are described for Middle to Upper Permian (Guadalupian) rocks of the Teresina Formation, Paraná Basin, from two localities in the São Paulo State, southwestern Brazil: Xavante Dam and Pau Preto Quarry. Paranacythere nigripallus gen. nov. and sp. nov., Velatomorpha xavante sp. nov., and Velatomorpha pseudoaltilis sp. nov. are herein described. The association Velatomorpha– Paranacythere is proposed as typical of Permian mixohaline environments of the Teresina Formation, and is the most abundant in the two studied localities. Paranacythere nigripallus gen. nov. and sp. nov. is proposed to accommodate a very abundant species with typically cytheroidean characteristics, and tentatively ascribed to the family Cytheruridae. Some ecological remarks are presented based on ostracod population age structure, biostratinomy and taxonomic composition of assemblages. The diagnosis of Velatomorpha Tibert & Dewey is emended.Novas espécies de ostracodes são propostas para rochas do Permiano Médio a Superior (Guadalupiano) da Formação Teresina, Bacia do Paraná, em duas localidades no Estado de São Paulo, sudeste do Brasil: Represa Xavante e Pedreira Pau Preto. Paranacythere nigripallus gen. nov. e sp. nov., Velatomorpha xavante sp. nov., and Velatomorpha pseudoaltilis sp. nov. são descritas. A associação entre os gêneros Velatomorpha e Paranacythere é interpretada como típica de ambientes mixoalinos da Formação Teresina, e são os ostracodes mais abundantes nas localidades aqui estudadas. Paranacythere nigripallus gen. nov. e sp. nov. é proposto para acomodar uma espécie com características tipicamente cytheroides e tentativamente atribuído à família Cytheruridae. Aspectos ecológicos são discutidos com base na estrutura populacional etária, biostratinomia e composição taxonômica das assembleias. É proposta uma emenda à diagnose de Velatomorpha Tibert & Dewey

Anatomia interna de alguns moluscos bivalves fósseis do grupo Bauru (Cretáceo Superior, Bacia Bauru), Brasil: implicações paleoecológicas

Detailed analyses in species of fossil bivalve mollusks of the Bauru Group (Late Cretaceous, Bauru Basin), exposed in the Sérgio Mezzarila scientifi c collection (IG/ SMA/SP), expose the preservation of musculature scars that have not been described as yet to Anodontites in São Paulo and Minas Gerais state. These features, which are associated to taxa-external anatomies, contribute to better understand the life habits of these freshwater organisms that were probably related to seasonal energetic variations in the rivers, where these organisms lived. Despite the fragmentary character of this record, the new information broadens the paleoecological panorama of bivalves in the Late Cretaceous of the Bauru Basin.Análises mais detalhadas em espécies de moluscos bivalves do Grupo Bauru (Cretáceo Superior, Bacia Bauru), depositadas na coleção científi ca Sérgio Mezzalira (IG/ SMA/SP), demonstram a preservação de feições musculares ainda não descritas para o táxon Anodontites nos estados de São Paulo e Minas Gerais. Tais feições, associadas à anatomia externa dos táxons, contribuem para o melhor entendimento do hábito de vida desses organismos dulciaquícolas que, provavelmente, estão intimamente relacionados às variações energéticas sazonais dos rios onde viviam. Apesar do registro esparso aqui notifi cado, as novas informações ampliam o panorama paleoecológico para os bivalves do Cretáceo Superior da Bacia Bauru.Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP

Unveiling the Permian and Triassic record of drilling predation on ostracods

Drill holes are relatively common trace fossils on post-Paleozoic ostracods (especially from the Cretaceous onwards) and usually ascribed to predation by Muricidae and Naticidae gastropods. In the last few decades, increasing reports of these marks on Late Paleozoic and Early Mesozoic ostracods appeared in the literature. In this paper, we review the drill holes on marine and mixohaline ostracods with emphasis on the Permian and Triassic intervals, based on a detailed analysis of their published records, as well as new specimens and data. Based on ichnological principles, analyzes of several types of marks observed on ostracodswere carried out to distinguish holes caused by predation on live individuals from the effects of dissolution and post-mortem bioerosion. The twenty-two marks identified as drill holes in this work are classified into nine types, ranging from Kungurian-Roadian to Rhaetian in age. The diversity of drill hole patterns supplies new evidence that the end-Permian biotic crisis influenced not only the global ostracod diversity, but also the trophic interactions. In the Late Triassic, the drilling predators were already deterred by increased thickness or complex ornamentation of bairdiid shells. Although the data do not permit precise identification of drilling predators, it is assumed that different animal groups might have performed this action throughout geologic time, due to the diversity of paleoenvironments and broad chronostratigraphic occurrence of drill holes analyzed. Potential drilling predators both in marine and mixohaline (paleo)environments are briefly discussed