Vera Maria Medina da Fonseca

Middle Devonian Crinoids from the Parnaiba Basin (Pimenteira Formation, Tocantins State, Brazil)

Abstract This contribution presents the first description of crinoids from western margin of Parnaíba Basin. It also presents their first description in the Pimenteira Formation (Devonian of the Parnaíba Basin, state of Tocantins, Brazil). The material is represented by hundreds of columnals, pluricolumnals, as well as isolated calyx plates. Columnal and pluricolumnal morphology allowed the identification of Laudonomphalus aff. L. tuberosus, and Exaesiodiscus dimerocrinosus n. sp. Based upon calyx plate morphology a new Rhodocrinitidae species was erected, Monstrocrinus incognitus n. sp. The genera Exaesiodiscus, Laudonomphalus, and Monstrocrinus were previously described from the Devonian of Amazonas Basin. Exaesiodiscus dimerocrinosus is also identified from the northwest margin of Paraná Basin. The Monstrocrinus occurrence is rare in the Middle Devonian, until now known in Germany, Spain, and Algeria Lower Devonian (upper Emsian) and only in northern Brazil in the Middle Devonian (Eifelian.) These facts provide valuable arguments for paleogeographic interpretations regarding the pattern of distribution of invertebrates in this region of Gondwana and suggest potential migration routes in northern Gondwana during the Devonian.

First Articulated Sponge from the Paleozoic of Brazil, and a New Organization of the Order Hemidiscosa

Abstract The first-described articulated Permian sponge from Brazil, representing Hexactinellida, has been recovered from the Lontras Shale in the Campáleo outcrop (Permian, Asselian–Sakmarian), Rio do Sul Formation, Mafra, in southern Brazil. It is assigned to the Hemidiscellidae and identified as Microhemidiscia greinerti n. sp. This fossil represents the first record of articulated sponges in Brazil from the Paleozoic Era, as well as the second species known from this genus. Moreover, it increases knowledge of the order Hemidiscosa, a monotypic group mostly defined by simple characters, which is here considered to comprise one family, Hemidiscellidae (Pennsylvanian-Cretaceous), and two genera, Hemidiscella and Microhemidiscia.

Tafocenoses da Formação Pimenteira, devoniano da Bacia do Parnaíba, Piauí: mapeamento, inventário e relevância patrimonial

During fieldwork conducted in the last ten years along the eastern border of the Parnaiba Basin in the State of Piaui, the continuous destruction of fossiliferous outcrops of the Pimenteira Formation has been observed and is clearly a matter of concern. In the current resumption of studies on this formation, the compilation of extensive inventories, covering all fossil groups, as well as the geological context, is a necessary means of protecting the geological heritage. The purpose of the present study is to establish the composition and mode of occurrence of the taphocoenoses and to evaluate the relative importance of the formations numerous fossiliferous sites, thus contributing to their conservation. The inventory incorporates unpublished data obtained since 2005, information available in the literature, unpublished dissertations and theses, field notebooks, photographs from different periods, and records of Pimenteira Formation samples deposited in the scientific collections of various museums and universities. Since the pioneering work of Caster (1948), the taphocoenoses of the Pimenteira Formation have been characterized as of erratic occurrence and hosted mainly by sandstones. These initial interpretations have undergone significant changes following the 2009 excursion, which revealed new fossiliferous horizons and sites with an array of differing lithologies (siltstones, sandstones, and conglomerates). Based on this inventory, we consider the following to be the most significant outcrops: Morro Branco de Kegel; Rio Sambito; Morro do Cemiterio; BR-316/km 318; Itainopolis; Riachao; Sao Joao Vermelho; and PI-466/km 12. These sites are the most frequently mentioned in the literature and some have particular historical value and also considerable diversity of taphocoenoses that provide data about the depositional environment, genesis, and age of the fossiliferous deposits. Furthermore, the fossils are better preserved and record more comprehensively the faunal and floral variations of the Devonian seas and adjacent fluvio-deltaic environments.

Silva Coutinho: uma trajetória profissional e sua contribuição às coleções geológicas do Museu Nacional

The career of Joao Martins da Silva Coutinho is linked to the history of the Museu Nacional in Rio de Janeiro to whose collections (especially geological) he contributed scientific information and material. On the Brazilian scientific stage, Silva Coutinho took part in major exploratory commissions in the latter half of the nineteenth century, mainly in the Amazon and in the Northeast. He collected and sent samples to the Museu Nacional for analysis, establishing deep ties with the institution and its staff. The article presents his contributions through an analysis of these documents and an examination of the geological collections that he sent to the institution and that remain part of its holdings.