The Lontras Shale (Permian, Paraná Basin) and its Fossils: Discovery, Taxonomic Identification and Present Knowledge

The Shaler Memorial Fund created in 1907 by students and admirers of the geologist Nathaniel Southgate Shaler, professor from Harvard University, allowed in its first contribution to fostering research, the organization of an expedition to the South and Southeast of Brazil. The expedition had the purpose to confirm Nathaniel`s ideas about the existence of glacial layers older then the Pleistocene. Led by the North American geologist Jay Backus Woodworthy and counting with participation of the Brazilian geologist Euzébio de Oliveira, the expedition not only proved the presence of glacial evidence but also discovered an intercalated fossiliferous marine shale, later known as Lontras Shale, Itararé Group. The fossils, initially studied by the American paleontologist Rudolf Ruedemann and by Euzébio de Oliveira, had its studies intensified from the 1980s with the identification of new outcrops and due the new data of the geological evolution of the carboniferous and permian sedimentary sucessions of the Paraná Basin. Economic disputes and discussion about the preservation of Lontras Shale outcrops, besides the discovered of new site namely as CAMPÁLEO, have reactivated the scientific interest about this unit and its paleontological content, increasing its studies. Poorly known by the Brazilian academic community, the historical context of the Lontras Shale is here reported, highlighting the importance of the Shale Memorial Fund as responsible for the geological and paleontological discoveries that have followed, for more than a century

Primeira ocorrência de Pleurodira (Testudines) para a Formação Guabirotuba, Bacia de Curitiba, Paraná, Brasil

The vertebrate fossil record of the Guabirotuba Formation, Curitiba Basin (Cenozoic), South Brazil, was restricted to a crocodyliform tooth and indeterminate bone fragments. New specimens collected in an outcrop located in Curitiba city, in the State of Paraná, are herein described and represent the first record of Pleurodira (Testudines) to this basin. The presence of aquatic Testudines associated to Crocodyliformes corroborates the lacustrine and fluvial paleoenvironment for the Guabirotuba Formation deposition and indicates a more humid climate than previously proposed.Keywords: Testudines, Pleurodira, Curitiba Basin, Guabirotuba Formation, Cenozoic.O registro de vertebrados fósseis da Formação Guabirotuba, Bacia de Curitiba (Cenozoico), no sul do Brasil, restringia-se a um dente de crocodiliforme e fragmentos ósseos indeterminados. Novos espécimes, coletados em afl oramento localizado na cidade de Curitiba, no Estado do Paraná, são aqui descritos e correspondem ao primeiro registro de Pleurodira (Testudines) para a bacia. A presença de Testudines aquáticos, associadas a Crocodyliformes corrobora a interpretação de um paleoambiente fluvio-lacustre para os depósitos da Formação Guabirotuba e indica um clima mais úmido do que previamente proposto.Palavras-chave: Testudines, Pleurodira, Bacia de Curitiba, Formação Guabirotuba, Cenozoico

Devonian agglutinated polychaete tubes: all in all it's just another grain in the wall

International audienceBiomineralized and organic metazoan tubular skeletons are by far the most common in the fossil record. However, several groups of organisms are also able to agglutinate particles to construct more rigid structures. Here we present a novel type of agglutinated tube from the austral and endemic palaeobiota of the Malvinokaffric realm (Devonian, Brazil). This fossil is characterized by an agglutinated tube made of silt-sized particles forming an unusual flanged morphology that is not known from the fossil record. Besides being able to select specific particles, these organisms probably lived partially buried and were detritus/suspension feeders. Comparisons across different modern groups show that these fossils are strongly similar to tubes made by polychaetes, specifically from the family Maldanidae. If this interpretation is correct, then an early divergence of the Sedentaria clade may have occurred before the Devonian

Organic walled microfossils in wet peperites from the early Cretaceous Paraná-Etendeka volcanism of Brazil

Abstract Large igneous provinces (LIPs) are major magmatic events that have a significant impact on the global environment and the biosphere, for example as triggers of mass extinctions. LIPs provide an excellent sedimentological and geochemical record of short but intense periods of geological activity in the past, but their contribution towards understanding ancient life is much more restricted due to the destructive nature of their igneous origin. Here, we provide the first paleontological evidence for organic walled microfossils extracted from wet peperites from the Early Cretaceous Paraná-Etendeka intertrappean deposits of the Paraná basin in Brazil. Wet peperites are a volcaniclastic rock formed by the interaction of lava and subaqueous sediments.The Paraná-Etendeka was formed during the Valanginian (ca. 132 Ma) as a continental flood basalt in present day South America and Namibia, and released enormous amounts of carbon dioxide, sulfur dioxide, methane and hydrogen fluoride into the atmosphere. The organic walled microfossils recovered from the Paraná-Etendeka peperites include pollen grains, spores, acritarchs, and other remains of unidentifiable organic matter. In addition to the peperites, organic walled microfossils were also found in heterolithic sandstones and interpillow sandstones. Our findings represent the first insight into the biodiversity of the Paraná Basin during the Early Cretaceous during a period of intense magmatism, and the microfossil assemblages corroborate a regional paleoclimatic transition from arid to more humid conditions that were likely induced by the volcanic activity. We corroborate the potential of wet peperite rocks as a valuable source of paleobiological data and emphasize the importance of sampling volcaniclastic units that have been traditionally considered with lower fossiliferous potential due to their igneous origin

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq