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Submitted by Fernanda Maria CTC/C (fernandalobo@uerj.br) on 2021-09-04T01:27:19Z No. of bitstreams: 1 Dissertação Geociências - Luis Otavio Rezende Castro - 2020.pdf: 2346232 bytes, checksum: c7cd02fdebf5295fd28bae06bc424eda (MD5) Made available in DSpace on 2021-09-04T01:27:19Z (GMT). No. of bitstreams: 1 Dissertação Geociências - Luis Otavio Rezende Castro - 2020.pdf: 2346232 bytes, checksum: c7cd02fdebf5295fd28bae06bc424eda (MD5) Previous issue date: 2020-08-26 A new basal notoungulate is described here. This is represented by maxillary and dental fragments, and by isolated teeth. The holotype and referred material were recovered from the “1968 Fissure” of the Itaboraí Basin, Rio de Janeiro State, Brazil. This basin, of Itaboraian age, has been regarded as early Eocene in recent contributions. The generalized appearance and brachydont dentition of the studied specimens, together with the presence of some typical traits (poorly developed entolophid, well-developed metacone column, etc.) indicate that it represents a Gen. et sp. nov. of Henricosborniidae. It is distinct from all other henricosborniids by a combination of characters, such as the presence of a long crochet, the development of two small cristae at the ectoloph, the large accessory trigonid cusp, among others. It is also easily distinguishable from typotherians by the absence of crista 1 and from toxodontians by the absence of crista intermedia. The phylogenetic analysis including all henricosbornid genera does not allow us to reach solid conclusions about the relationship of the new taxon with the other members of this group. It did not present conclusive evidence for the synonymy between Itaboraitherium atavum and Othnielmarshia pristina, previously suggested. Moreover, the reference of these forms as henricosborniids, based on the complex occlusal dental pattern observed in both cases, is questioned. Finally, based on the observations made in the present study, we consider that the accessory trigonid cuspid, referred in some contributions as a paraconid, may be associated with some cusps located mesially to the metaconid and identified as pseudoparaconids in past studies. Um novo notoungulado basal é descrito neste trabalho. Este morfótipo é representado por fragmentos de maxilar, de dentário e por dentes isolados. O holótipo e o material referido foram coletados na "Fenda de 1968" da Bacia de Itaboraí, Estado do Rio de Janeiro, Brasil. Esta bacia é de idade Itaboraiense, que tem sido considerada como do Eoceno inicial em recentes contribuições. A dentição do morfótipo é braquiodonte, apresentando alguns caracteres (entolofído pouco desenvolvido, coluna de metacone bem desenvolvida, etc.) que indicam tratar-se de um Gen. et Sp. Nov. de Henricosborniidae, é diferente de todos os outros henricosborniídeos por uma combinação de caracteres, como presença de um longo crochê, desenvolvimento de duas pequenas cristas no ectolofo, grande cúspide acessória no trigonido, dentre outras. É também facilmente distinguível dos Typotheria pela ausência da crista 1 e de Toxodontia pela ausência da crista intermédia. A análise filogenética na qual foram incluídos todos os henricosbornideos não nos permite chegar a conclusões solidas da relação Gen. et sp. nov com os demais membros deste grupo. Ela também não revelou evidências conclusivas sobre a sinonímia entre Itaboraitherium atavum e Othnielmarshia pristina sugerida anteriormente, assim como seu posicionamento dentre os henricosborniídeos, devido ao complexo padrão dentário observado na face oclusal de ambas as espécies. Por fim, com base nas observações feitas no presente estudo, a cúspide acessória do trigonido, referida em algumas contribuições como paraconido, pode estar associada a algumas cúspides localizadas mesialmente ao metaconido e identificadas como pseudoparaconido em estudos anteriores.

Sparassodonts were the main mammalian predators during most of the Cenozoic in South America. The lower Eocene Itaboraí Basin/ Formation includes the second oldest fossil records of this group in South America: Patene Simpson and cf. Nemolestes Ameghino. Patene is by far the most abundant sparassodont from this formation, with more than 30 specimens referable to a single taxon, Patene simpsoni Paula Couto. Some specimens recovered from the Quebrada de Los Colorados Formation (formerly Lumbrera Formation – middle Eocene) in Northwestern Argentina have been also referred to P. simpsoni. In order to test the affinities of Patene and the taxonomy of the Argentinean specimens, we performed a review of the genus. Specimens of Patene from Northwestern Argentina show significant differences from the specimen from Brazil, including: smaller size; a relatively larger paraconid; and smaller metaconid, entoconid and hypoconid. As a result, the specimens from the Quebrada de Los Colorados Formation are assigned to a new taxon, Patene coloradensis sp. nov. The results of our phylogenetic analysis recover Patene as a basal sparassodont and support previous hypotheses that exclude Patene from the “Hathliacynidae”. The results also supported the hypothesis that Allqokirus australis Marshall & Muizon and Mayulestes ferox Muizon from the Tiupampa Basin (Santa Lucía Formation, lower Paleocene – Tiupampan SALMA), Bolivia, are the oldest known representatives of the Sparassodonta. The results also supported the monophyly of the Pucadelphyda with the inclusion of the Jaskhadelphyidae and closely related taxa in this group in addition to the Pucadelphyidae and Sparassodonta. The late Cretaceous North American Varalphadon Johanson was not recovered as a representative of the Sparassodonta in our phylogenetic analysis. Based on our results and the current fossil record, the Sparassodonta should be considered an endemic South American lineage. Fil: Rangel, Caio. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Carneiro, Leonardo. Sociedade de História Natural. Laboratório de Paleontologia e Paleoecologia; Brasil. Universidade Federal do Rio de Janeiro; Brasil Fil: Paglarelli Bergqvist, Lílian. Universidade Federal do Rio de Janeiro; Brasil Fil: Olivera, Édison. Universidade Federal de Pernambuco; Brasil Fil: Goin, Francisco Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina Fil: Babot, María Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Fundación Miguel Lillo; Argentina

Abstract: Riostegotherium yanei from the Itaborai Basin, Brazil, is the oldest known Xenarthra. This paper aims to describe the internal morphology of the osteoderms of Riostegotherium yanei from the perspective of histology and micro-CT approaches, expanding the available data on cingulate osteoderm microstructure. Seven osteoderms of R. yanei were used for the internal microstructure description and eight of Dasypus novemcinctus for comparison. The osteoderms of Riostegotherium yanei lacks the diploe-like structure typical of glyptodonts but has a three-layered structure composed of two layers of non-Haversian compact bone enclosing a central layer of primary and secondary osteons. This internal organization is distinct from other Astegotheriini of comparable age, but similar to Dasypus. The 3D reconstruction of Riostegotherium yanei revealed two patterns of internal organization. Pattern 1 of movable osteoderm is composed of large remodeled areas at the base and a more compact bone at the tongue; in Pattern 2 (both movable and buckler), the internal cavities are much smaller, more numerous, and more interconnected to each other. In one buckler osteoderm, the cavities are organized somewhat radially with a compact central region (Pattern 1). Pattern 1 of both movable and buckler osteoderms resemble that of Dasypus.

Submitted by Boris Flegr (boris@uerj.br) on 2021-01-05T15:35:45Z No. of bitstreams: 2 Dissertacao Gustaco Pereira pt1.pdf: 2802383 bytes, checksum: a5c203905c4aec78e1fd856744999569 (MD5) Dissertacao Gustavo Pereira pt2.pdf: 2970799 bytes, checksum: 2c78f96ab670f0028dc8913da28f4db1 (MD5) Made available in DSpace on 2021-01-05T15:35:45Z (GMT). No. of bitstreams: 2 Dissertacao Gustaco Pereira pt1.pdf: 2802383 bytes, checksum: a5c203905c4aec78e1fd856744999569 (MD5) Dissertacao Gustavo Pereira pt2.pdf: 2970799 bytes, checksum: 2c78f96ab670f0028dc8913da28f4db1 (MD5) Previous issue date: 2015-06-01 Agência Nacional do Petróleo The travertine located in the Itaborai Basin in the state of Rio de Janeiro, designated Itaborai Formation and dated back Paleocene for their content in fossil vertebrates are deposited in small half graben basin, despite the small size of the basin (1,5Kmx0,5Km) it represents a huge source of information including a diverse preserved biota, presence of sinter along travertine precipitation, exposition of alcaline dyke and the possibility of analog model for pre-salt reservoir. Most of the studies regarding the basin are related to the extensive fossil community from the lake-fill facies association; facies not directly related to the thermal precipitation.The banded travertine and facies associated lacks of studies envolving petrography and facies association. The Research presented intend to recognize the remarking structures and textures in thin sections, describe the facies, identify the sinter-travertine relationship as well, in order to establish a facies association and the geologic interpretation assisted with isotope δ13C/δ18O analysis. To achieve this goal, mapping, sedimentologic, petrographic and isotopic studies were carried out. As Results, two depositional settings were recognized; travertine deposited along the active fault border and the travertine deposited in the less tectonic affected portion of the basin. For these two settings was established a profile with their deposits characteristics and its deposional processes. The conclusion obtained were the macro- and microscopic features observed indicated a presence of major abiotic influence during the process of thermal precipitation, controlled mainly by tectonic activity pulses of the distentional hemi-graben system, while the stable isotope ratios provided contrasting data to the characteristic thermogene travertine signature, raising discussion of mixed processes afecting the isotopes and the possible influence of magmatic events, diagenesis and climate events in Isotopic fractionation Os travertinos localizados na Bacia de Itaboraí, no estado do Rio de Janeiro, designados de Formação Itaboraí e datados no Paleoceno através de seu conteúdo em fósseis vertebrados, são depositados em uma pequena bacia hemi-graben que apesar de sua pequena dimensão (1,5Kmx0,5Km) representa uma enorme fonte de conhecimento, possui uma biota diversificada preservada, derrame de dique alcalino, presença de deposição de sílica sinter associada aos travertinos e a possibilidade de modelo análogo para o reservatório do pré-sal. A maioria dos estudos estão relacionados à extensa comunidade fóssil da bacia; estas fácies não estão diretamente relacionadas com a precipitação do travertino. O estudo dos travertinos e de suas fácies associadas carecem de estudos envolvendo petrografia e estudos de fácies. A pesquisa apresentada pretende reconhecer as feições estruturais e texturais nas seções delgadas, descrever as fácies, identificar a relação sinter-travertino, a fim de estabelecer uma associação de fácies e uma interpretação geológica acompanhada com a análise de isótopos de C13 / O18. Foram realizados mapeamento das fácies, análise sedimentológica, petrográfica e estudos isotópico. Como resultados, dois contextos deposicionais foram apresentados; os travertinos depositados ao longo dos limites de falha ativa e os travertinos depositados nas porções menos afetadas tectonicamente da bacia. Para estes dois ambientes foi estabelecido um perfil com suas características genéticas deposicionais e de seus processos deposicionais. O trabalho permitiu concluir que as feições macro e microscópicas observadas indicaram uma presença de grande influência abiótica durante o processo de precipitação termal, controlado principalmente por pulsos de atividade tectônica no sistema hémi-graben distensivo. Os resultados dos isótopos estáveis apresentaram razões contrastantes com a assinatura isotópica característica dos travertinos termógenos, promovendo uma discussão a respeito de mistura de processos no fracionamento isotópico e possível influência mantélica, diagenética e climática nas razões isotópicas