Artur Chahud

Anfíbio e palaeonisciformes da porção basal do Membro Taquaral, Formação Irati (Permiano), estado de São Paulo, Brasil

A regiao centro-leste do Estado de Sao Paulo possui boas exposicoes de sedimentos das sequencias permocarboniferas da Bacia intracratonica do Parana. Inicia-se com depositos do Grupo Itarare, Permocarbonifero, seguidos pelos da Formacao Tatui, Grupo Guata, do Eopermiano, ambos do Supergrupo Tubarao. O grupo seguinte, Passa Dois, compreende, na regiao estudada do Estado de Sao Paulo, as formacoes Irati, Eopermiano, e Corumbatai, Mesopermiano. Dois membros da Formacao Irati sao reconhecidos na regiao, Taquaral e Assistencia. A maior parte do Membro Taquaral e constituida de sedimentos siltico-argilosos, cinzentos, com laminacoes plano-paralelas. Delgados arenitos ocorrem na porcao basal do membro. Um destes arenitos, de 9,5 cm de espessura, em contato discordante com a Formacao Tatui, contem fosseis de vertebrados diversificados. A descricao de um fragmento mandibular de Palaeonisciformes, um dente isolado e um fragmento mandibular de anfibio Temnospondyli, constituem objeto desta contribuicao. Estes fosseis estao associados com outros taxa de Chondrichthyes e Osteichthyes. Fica em aberto a possibilidade de considera-los representantes de taxa da bacia do Parnaiba, Formacao Pedra do Fogo, de idade semelhante, Brasilichthys macrognathus Palaeonisciformes, e Prionosuchus plummery, Temnospondyli. Somente com fosseis em melhor estado de conservacao, seria possivel esclarecer essa questao.

Registro de paleoniscóides na base do Membro Taquaral, Formação Irati, Permiano da Bacia do Paraná

A conglomeratic sandstone, the lowest bed of the Taquaral Member, the basal unit of the Permian Irati Formation (Passa Dois Group), in the Municipality of Rio Claro, east-central State of Sao Paulo, Brazil, contains several species of vertebrate fossils. Chondrichthyes of different orders are represented by teeth and spines, but the most abundant fossils belong to the Osteichthyes as represented by paleoniscoid scales, teeth and bone fragments. The Actinopterygii are the commonest fish remains in this unit.

Paleontology of Taquaral Member silty shale in the State of São Paulo

The Irati Formation, Permian (Cisularian) from RESUMO: A Formacao Irati, unidade permiana do Cisulariano da Brazilian Parana Basin, at the State of Sao Paulo, is divided into two members: Taquaral (basal) and Assistencia (top). The Taquaral Member exhibits two facies: basal, composed by sandstones and con- glomerates, 0.1-1 m thick, and silty shales, 5-30 m thick. The few papers dealing with the paleontology of the silty shale facies are scar- ce so the main goal of this work was to widen the knowledge of the fossils of this unit. The reported fossils herein related are acritarchs, algae, crustaceans of the genus Clarkecaris and forms taxonomically indeterminate, besides and loose vertebrate remains. Other fossils and microfossils are reported in literature but without descriptions or illustrations. The fossil record of the silty shale allowed to put forth a paleoenvironmental suggestion of a restricted low salinity body of water.

Sarcopterygii do Eopermiano da Bacia do Paraná, Estado de São Paulo

This contribution comprises a review of Early Permian Sarcopterygii (Coelacanthimorpha - coelacanths; Tetrapodomorpha - Osteolepimorpha and tetrapods) of the Parana Basin in the state of Sao Paulo. The other important group of sarcopterygians - Dipnoi (lungfishes) - have still not been recorded in Sao Paulo in the Early Permian. The Coelacanthimorpha have been reported in the Itarare Group, Tatui and Irati formations. The sandstone and conglomerate at the base of the Taquaral Member of the Irati Formation are rich in icthyofossils, including labyrinthodont teeth that have been assigned to the Tetrapodomorpha. These teeth range from a few millimeters to a few centimeters in length, which makes them the largest teeth in the Permian of the State of Sao Paulo. The most frequent fish remains in the silty shale facies of the Taquaral Member are scales of Coelacanthimorpha, which may reach a few centimeters in size. Currently the coelacanths live in deep marine environments. However, during the Paleozoic they lived in waters of different salinities as well as in fresh waters. The Tetrapodomorpha were also able to live in waters of varied salinities and in continental settings. The paleoenvironmental analysis of ancient deposits with these groups of fossils thus requires a thorough survey of their sedimentary context as well as the associated paleobiota.

Mobilidade, subsistência e apropriação do ambiente: contribuições da zooarqueologia sobre o Sambaqui do Bacanga, São Luís, Maranhão

Human patterns of subsistence and/or mobility may be reflected in the zooarchaeological record from estuarine mangrove shell mounds and other coastal ecotones. In a biogeographical domain, such as mangroves and their associated ecotones, the availability of much of the animal resources may increase due to seasonality and life cycle of organisms and become more accessible within an area of resource capture. Thus, the record of shell mounds, characterized by a large number of remains of molluscs and fish in relation to other taxa, may indicate either a taphonomic bias, as well as issues related to the calculation of the biomass in the laboratory and/or changes in subsistencedue to modifications of the landscape in the annual cycle. This work aims to address the questions and hypotheses about patterns of mobility tied to models of subsistence and ownership of the environment by pasthuman societies in coastal shell mounds from Maranhao, with special emphasis on the Sambaqui do Bacanga, inserted in a context of mangrove estuary. So far it could be concluded that there were no significant taxonomic changes over the archaeological strata.