Article

LOS VERTEBRADOS FÓSILES DEL PALEOZOICO Y MESOZOICO DEL ESTADO DE TOCANTINS (BRASIL): PRELIMINAR SÍNTESIS 1 THE FOSSIL VERTEBRATES OF PALEOZOIC AND MESOZOIC FROM TOCANTINS STATE (BRAZIL): A PRELIMINARY SYNTESIS

Caminhos de Geografia 11/2010; 11(36):224-236.

ABSTRACT RESUMO O registro dos vertebrados fósseis deportados no estado do Tocantins (Norte do Brasil), junto ao conhecimento geológico e paleontológico, é escasso em comparado com outros estados brasileiros. Recentemente, as faunas de vertebrados estão começando a serem descritas e analisadas, podendo aumentar a lista de taxa aqui apresentados. Esta fauna provém de cinco localidades fossilíferas, e consiste essencialmente em restos fragmentários (escamas, espinhos, dientes e etc) de paleonisciformes, elasmobranquiomorfos, celatantídeos e de um icnofóssil de Sauropoda. Os níveis sedimentares fossilíferos das rochas pertencem a Formação Pedra de Fogo (Permiano Superior) e Formação Corda (Cretácio Inferior) da Bacia do Parnaíba. ABSTRACT The occurrence of fossil vertebrates in Tocantins (Northern, Brazil) together with its knowledge of geology and paleontology is very poor compared to other states of Brazil. Recently, the vertebrate fauna started to be well described and comprehended. It consists essentially of fragmentary remains (scales, fins, teeth etc.) of paleonisciforms, elasmobranchiomorphs, coelacanthids and Sauropoda ichnofossil from five localities. The fossiliferous tocks belong to the Pedra de Fogo (Late Permian) and Corda formations (Lower Cretaceous), Parnaiba Basin.

1 Bookmark
 · 
275 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the 80´s, Leonardi treated the presence of a vertebrate ichnological locality from the Barremian Corda Formation, Parnaíba Basin, on the left bank of the Tocantins river, near of the São Domingos town, Itaguatins, State of Tocantins, Brazil. Originally, the record was composed of at least seven in situtrackways, accounting for fifty six tracks. Since 2011, the Hydroelectric Power Plant do Estreito has begun to work, causing the development of a water reservoir 160 km upstream to the ichnological site,causing periodic and highly energetic floods over the footprints-bearing level and altering it. The imprints are poorly to moderate preserved, but it is possible to distinguish the general morphology and the spatial arrangement of the footprints. The specimens are represented bypes imprints, mostly circular to subcircular, with no digital and claw impressions. No distinguishable manus imprints are present. The trackways are relative narrow with respect to the size of the tracks, so they are considered into the Parabrontopodus-like category. The São Domingos tracks have been originally assigned to iguanodontid dinosaurs, and posteriorly related to a sauropodian origin This idea is herein accepted, particularly to a basal sauropod, basal macronarians, or diplodocoids. Up to date, the tracks from the São Domingos locality are the only vertebrate fossil record from the Corda Formation, meaning an important contribution to the Cretaceous ichnofauna from South America.
    Journal of South American Earth Sciences 09/2014; DOI:10.1016/j.jsames.2014.09.023 · 1.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Brazilian records on Xenacanthiformes include teeth and cephalic spines from the Parnaíba, Amazonas and Paraná basins. This work describes a new species of Xenacanthidae, collected in an outcrop of Serrinha Member of Rio do Rasto Formation (Wordian to Wuchiapingian), Paraná Basin, municipality of Jacarezinho, State of Paraná. The teeth of the new species are two or three-cuspidated and the aboral surface show a smooth concavity and one rounded basal tubercle. The coronal surface presents one semi-spherical and subcircular coronal button, and also two lateral main cusps and one central (when present) with less than one fifth of the size of the lateral cusps in the labial portion. The lateral cusps are asymmetric or symmetric, rounded in transversal section, lanceolate in longitudinal section, devoid of lateral carinae and lateral serrations, and with few smooth cristae of enameloid. In optical microscope the teeth show a trabecular dentine (osteodentine) base, while the cusps are composed by orthodentine, and the pulp cavities are non-obliterated by trabecular dentine. The fossil assemblage in the same stratigraphical level and in the whole Rio do Rasto Formation indicates another freshwater record for xenacanthid sharks.
    Anais da Academia Brasileira de Ciências 03/2014; 86(1):135-45. DOI:10.1590/0001-37652014107612 · 0.85 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: On the left bank of the Tocantins River, near São Domingos, State of Tocantins, northern Brazil, there are at least six vertebrate trackways from the Barremian Corda Formation (Parnaı´ba Basin) first reported by Leonardi (BuenosAires 1:215–222, 1980) and assigned to iguanodontid dinosaurs. Later, these trackways were reassigned as belonging to sauropods. Until 2011, this locality was subject to river floods during seasonal rain cycles. Since then, the amount of water on the flatstones was substantially modified due the implantation of the ‘‘Usina Hidroeletrica de Estreito’’, which has a dam 160 km upstream from the trackways locality. Recent fieldwork in the area has revealed that only a part of four original trackways is still preserved. The specimens, with poor to moderate preservation, are represented by large semicircular pes imprints lacking digital impressions mostly overlapping the hand print, which supports a sauropodian origin. Here, the authors consider and suggest geotourism as an important tool to protect and preserve the São Domingos’ footprints.
    Environmental earth sciences 11/2014; 73(8). DOI:10.1007/s12665-014-3754-z · 1.57 Impact Factor

Full-text

Download
134 Downloads
Available from
May 17, 2014