Revista Brasileira De Paleontologia最新文献

{"title":"Nanofósseis calcários do Mioceno da Bacia do Baixo Tejo, Portugal","authors":"João da Fonseca Gomes de Lemos, Geize Carolinne Correia Andrade Oliveira","doi":"10.4072/RBP.2021.1.04","DOIUrl":"https://doi.org/10.4072/RBP.2021.1.04","url":null,"abstract":"Calcareous nannofossils of the Lower Tejo Basin Miocene, Portugal. This study presents the taxonomy, biostratigraphy, and paleoecology of calcareous nannofossils from an outcrop on the border of Foz da Fonte beach, geologically setting in the Neogene of the Lower Tejo Basin, Portugal. The taxonomic description allowed us to identify 19 calcareous nannofossils species belonging to ten genera (Helicosphaera, Pontosphaera, Reticulofenestra, Cyclicargolithus, Coccolithus, Discoaster, Sphenolithus, Umbilicosphaera, Calcidiscus, and Thoracosphaera). Based on the stratigraphic range of Discoaster druggii, Reticulofenestra lockeri and Helicosphaera ampliaperta the section was defined in the NN2 and CN1 biozones, within the Burdigalian (lower Miocene). Quantitative analysis showed a significant variation in species diversity as a function of depth, as well as a relationship between species richness and the calcium carbonate content present in these rocks. According to these data, mainly due to the abundance of Reticulofenestra spp., Coccolithus spp. and Helicosphaera spp., it is possible to infer that this was a nutrient-rich nearshore marine environment (eutrophic) influenced by warm water conditions.\u0000Keywords: calcareous nannofossils, taxonomy, biostratigraphy, paleoecology, Neogene, Lower Tejo Basin.\u0000RESUMO – Este estudo apresenta a taxonomia, bioestratigrafia e paleoecologia dos nanofosseis calcarios presentes nas rochas que afloram as margens da praia da Foz da Fonte, geologicamente pertencentes ao Neogeno da Bacia do Baixo Tejo, Portugal. A descricao taxonomica permitiu identificar 19 especies de nanofosseis calcarios pertencentes a dez generos (Helicosphaera, Pontosphaera, Reticulofenestra, Cyclicargolithus, Coccolithus, Discoaster, Sphenolithus, Umbilicosphaera, Calcidiscus e Thoracosphaera). Com base na distribuicao bioestratigrafica de Discoaster druggii, Reticulofenestra lockeri e Helicosphaera ampliaperta a secao foi definida pertencendo as biozonas NN2 e CN1, dentro do Burdigaliano (Mioceno inferior). A analise quantitativa mostrou significativa variacao na diversidade de especies em funcao da profundidade e, tambem, uma relacao entre a riqueza especifica e abundância com o teor de carbonato de calcio presente nas rochas. De acordo com esses dados, principalmente pela abundância de Reticulofenestra spp., Coccolithus spp. e Helicosphaera spp. e possivel inferir que tratava de um ambiente marinho proximo a costa, rico em nutrientes (eutrofico), influenciado por massas de aguas quentes.\u0000Palavras-chave: nanofosseis calcarios, taxonomia, bioestratigrafia, paleoecologia, Neogeno, Bacia do Baixo Tejo.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"24 1","pages":"47-61"},"PeriodicalIF":0.7,"publicationDate":"2021-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45112119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoclimatic inferences based on wood growth interruptions in Late Triassic flood deposits from the southernmost Brazilian Gondwana","authors":"A. M. Siegloch, M. Guerra-Sommer, C. Schultz, E. Barboza","doi":"10.4072/RBP.2021.1.01","DOIUrl":"https://doi.org/10.4072/RBP.2021.1.01","url":null,"abstract":"The goals of this study were to establish patterns in a silicified wood assemblage to depict the evolution patterns of the Triassic paleoclimate in southern Brazilian Gondwana during an interval of global arid to semi-arid climatic context, and the taphonomic process that led to the preservation of the so-called “Petrified Forest”, which is preserved in the central area of the state of Rio Grande do Sul. Analyses were developed with an assemblage of 13 permineralized conifer wood, using standard thin sections, whose anatomical details were studied in transmitted light. Ground-Penetrating Radar was used to obtain information about the depositional characteristics of the site. Main results are: true growth rings are absent in all samples, and the boundaries of the interruption zones are marked by an abrupt decline in cell diameter, but they are not accompanied by a reduction of cell wall thickness. The subsequent reversion to normal tracheid diameter is also abrupt, revealing the return of the previous growing conditions. Ground-penetrating Radar analyses confirmed that the Mata Sequence deposits correspond to a river. The identification of growth interruption zones in a Late Triassic wood assemblage in southernmost Brazilian Gondwana (Paleobotanic Garden of the city of Mata, RS) indicates the presence of tropical, temporarily dry climate conditions, characterized by irregular, short-term environmental disturbances to growth. The taphonomic process was related to a river-channel infilling depositional process, under the influence of high-energy flood events that dragged and buried the trees.\u0000Keywords: Wood growth patterns, Mata sequence, gymnosperms, Triassic climate, petrified forest.\u0000RESUMO – O objetivo do presente trabalho foi obter assinaturas climaticas por meio da analise de padroes de crescimento em uma associacao de lenhos silicificados a fim de retratar os padroes de evolucao do paleoclima no Triassico no Gondwana sul-brasileiro durante um intervalo de condicoes climaticas globais aridas-semiaridas e esclarecer o contexto sedimentar e o processo tafonomico relacionado a preservacao da “Floresta Petrificada”, preservada na area central do Estado do Rio Grande do Sul. Secoes delgadas foram elaboradas a partir de 13 amostras de lenhos permineralizados, sendo os detalhes anatomicos estudados em microscopia optica sob luz transmitida. A tecnica de Penetracao do Solo por Radar (Ground Penetrating Radar - GPR) foi utilizada para obter informacoes sobre as caracteristicas deposicionais. Os principais resultados foram: ausencia de verdadeiros aneis de crescimento nas amostras e todos os especimes sao caracterizados por interrupcoes de crescimento concentricas. Os limites das zonas de interrupcao sao marcados por um declinio abrupto no diâmetro da celula, mas nao sao acompanhados por uma reducao da espessura da parede celular. A reversao subsequente para o diâmetro traqueideo normal tambem e abrupta, revelando o retorno das condicoes de crescimento ","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"24 1","pages":"3-20"},"PeriodicalIF":0.7,"publicationDate":"2021-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47100028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age of the Post-rift Sequence I from the Araripe Basin, Lower Cretaceous, NE Brazil: implications for spatio-temporal correlation","authors":"J. Coimbra, Tiago Freire","doi":"10.4072/RBP.2021.1.03","DOIUrl":"https://doi.org/10.4072/RBP.2021.1.03","url":null,"abstract":"A robust biostratigraphic zonation based on microfossils supports the stratigraphic framework and correlation of the interior basins of the Lower Cretaceous of NE Brazil. This zonation has also allowed correlations with coeval sections in the Brazilian marginal basins and in the Gabon and Congo basins (central-west Africa). These records, consisting mainly of non-marine sediments, were a great challenge with regard to the correlation with the International Chronostratigraphic Chart. Therefore, local stages were used, the most recent being the Alagoas local Brazilian Stage, with which the Post-rift Sequence I of the Araripe Basin is related. Regarding lithostratigraphy, this sequence includes the Rio da Batateira (Barbalha for some authors) and Santana formations, the last one with the famous Crato, Ipubi, and Romualdo members, from the base to the top. Although currently there is a consensus on the age of the Alagoas local Brazilian Stage in the Araripe Basin, recently a new age for at least part of the Post-rift Sequence I was proposed. This new proposal, based on isotopic analysis of Re-Os, arose as a panacea to correlate the Rio da Batateira Formation and the Crato and Ipubi members with the international stages. Surprisingly, their authors, although on the one hand, they seem to underestimate biostratigraphic results, on the other they seek to support their proposal from microfossils studied by previous authors, but they do so in an inappropriate way, leading readers to misinterpret their results. Therefore, this paper presents a critical review on the age of the Alagoas local Brazilian Stage in the Araripe Basin and nearby basins, refuting a Barremian age for part of the Post-rift Sequence I.\u0000Keywords: Alagoas local Brazilian Stage, biostratigraphy, ostracods, palynomorphs, radiometric ages.\u0000RESUMO – Um robusto zoneamento bioestratigrafico baseado em microfosseis suporta o arcabouco estratigrafico e a correlacao dos estratos eocretaceos das bacias interiores do NE do Brasil. Esse zoneamento permite tambem correlacoes com secoes coevas nas bacias marginais brasileiras e nas bacias do Gabao e Congo (centro-oeste da Africa). Tais registros, compostos principalmente por sedimentos nao-marinhos, foram um grande desafio em termos de correlacao com a Tabela Cronoestratigrafica Internacional. Assim, foram empregados andares locais, sendo o estratigraficamente mais alto o Andar Alagoas, com o qual a Sequencia Pos-rifte I da Bacia do Araripe esta relacionada. Quanto a litoestratigrafia, essa sequencia inclui as formacoes Rio da Batateira (Barbalha para alguns autores) e Santana, a qual esta subdividida nos famosos membros Crato, Ipubi e Romualdo, da base para o topo. Embora atualmente haja consenso sobre a idade do Andar Alagoas naBacia do Araripe, recentemente foi proposta uma nova idade para parte da Sequencia Pos-rifte I. Essa nova proposta, baseada em analises isotopicas de Re-Os, foi apresentada como uma panaceia para correlacionar a formacao Rio","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"24 1","pages":"37-46"},"PeriodicalIF":0.7,"publicationDate":"2021-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46402013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agathoxylon santacruzense Kloster & Gnaedinger from the Lower–Middle Jurassic Kota Formation, India and its paleoenvironmental implications","authors":"C. Chinnappa, P. S. Kavali","doi":"10.4072/rbp.2020.4.01","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.01","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49164397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New record of Prozostrodon brasiliensis (Eucynodontia: Prozostrodontia) from its type-locality (Upper Triassic, Southern Brazil): comments on the endocranial morphology","authors":"L. Kerber, A. Martinelli, P. Rodrigues, A. M. Ribeiro, C. Schultz, M. Soares","doi":"10.4072/rbp.2020.4.04","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.04","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"23 1","pages":"259-269"},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45519160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Presencia de Proterotheriidae (Mammalia, Litopterna) en el Pleistoceno de las Pampas Bonaerenses","authors":"Federico L. Agnolin, Nicolas Chimento, Marcelo R. Bruyere","doi":"10.4072/rbp.2020.4.05","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.05","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45388997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fire events and vegetation dynamics during the late Pleistocene-Meghalayan interval in the southernmost Brazilian coastal plain","authors":"Veridiana Ribeiro, M. Guerra-Sommer, R. Menegat, Lidia A. Kuhn, J. Simões, Ricardo Burgo Braga, S. G. Bauermann, Wagner G. Silva","doi":"10.4072/rbp.2020.4.02","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.02","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"23 1","pages":"234-250"},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44838585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstrução da temperatura e da precipitação média anual com base em acumulações de macrorrestos vegetais da Bacia do Rio Itanhaém, São Paulo, Brasil","authors":"Francisco Santiago, F. Ricardi-Branco","doi":"10.4072/rbp.2020.4.03","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.03","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"23 1","pages":"251-258"},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47824109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new invertebrate from the Ponta Grossa Formation (Devonian), Paraná Basin, Brazil","authors":"A. Chahud, T. Fairchild","doi":"10.4072/rbp.2020.4.06","DOIUrl":"https://doi.org/10.4072/rbp.2020.4.06","url":null,"abstract":"","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42927183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comments on additional dinosaur specimens from the Janner site (Upper Triassic of the Paraná Basin), southern Brazil","authors":"R. Müller","doi":"10.4072/rbp.2020.3.02","DOIUrl":"https://doi.org/10.4072/rbp.2020.3.02","url":null,"abstract":"The Janner site (Upper Triassic of Southern Brazil) has been intensely explored, yielding constant new findings in recent years. Among these some fragmentary dinosaur specimens still not published were sampled. In this contribution, we describe these specimens, which represent five individuals, in order to increase our understanding on the anatomy of the dinosaurs that compose the paleofauna of the Janner site. The specimen CAPPA/UFSM 0270 is comprised of a series of six articulated presacral vertebrae, plus two isolated vertebrae associated with a right femur. UFRGS-PV-1232-T comprises a sacrum and a left ilium. CAPPA/UFSM 0271 comprises a right humerus that lacks the middle portion of the diaphysis. CAPPA/UFSM 00272 and 2073 are both comprised of an isolated femur each. The fragmentary condition of the materials hampers any less inclusive assignation. However, the morphology of the elements resembles those of coeval dinosaurs. Furthermore, the new specimens increase our knowledge on the morphology of some structures poorly understood from the dinosaurs of Janner site, such as the hindlimb and axial skeleton.\u0000Keywords: Hyperodapedon Assemblage Zone, Carnian, Saurischia, Sauropodomorpha, Archosauria, Dinosauria.\u0000O sitio Janner (Triassico Superior do Sul do Brasil) tem sido explorado intensamente, produzindo constantes novos achados nos ultimos anos. Dentre estes, restos de dinossauros ainda nao publicados foram recuperados. Nesta contribuicao nos descrevemos estes especimes, que totalizam cinco individuos, com o objetivo de aumentar o entendimento sobre a anatomia e amostragem de dinossauros que compoem o conteudo paleofaunistico do sitio Janner. O especime CAPPA/UFSM 0270 e composto por uma serie de seis vertebras pre-sacrais articuladas, alem de duas vertebras isoladas e um femur direito. UFRGS-PV-1232-T corresponde a um sacro e um ilio esquerdo. CAPPA/UFSM 0271 compreende um umero direito que carece de sua diafise. CAPPA/UFSM 0272 e 0273 compreendem um femur isolado cada. A condicao fragmentaria dos especimes impede uma atribuicao taxonomica menos inclusiva. Porem, a morfologia dos elementos lembra a de dinossauros coevos. Alem disso, os novos especimes aumentam nosso conhecimento sobre a morfologia de estruturas ainda pouco conhecidas de dinossauros do sitio Janner, como o membro anterior e o esqueleto axial.\u0000Palavras-chave: Zona de Associacao de Hyperodapedon, Carniano, Saurischia, Sauropodomorpha, Archosauria, Dinosauria.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"23 1","pages":"171-184"},"PeriodicalIF":0.7,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48632708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}