Upper Cretaceous
Mostrando 1-12 de 38 artigos, teses e dissertações.
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1. Pterodactyloid pterosaur bones from Cretaceous deposits of the Antarctic Peninsula
Abstract Fossil vertebrates from Antarctica are considerably rare, hampering our understanding of the evolutionary history of the biota from that continent. For several austral summers, the PALEOANTAR project has been carrying out fieldwork in the Antarctic Peninsula in search for fossils, particularly Cretaceous vertebrates. Among the specimens recovered so
An. Acad. Bras. Ciênc.. Publicado em: 02/12/2019
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2. The sedimentary record of wet and dry eolian systems in the Cretaceous of Southeast Brazil: stratigraphic and paleogeographic significance
Abstract Sedimentologic and stratigraphic studies of paleo-deserts from the Brazilian Cretaceous are of great potential to understand the paleoclimate and paleogeography of Gondwana during its final rifting stage. Herein, we describe and discuss two depositional units characterized by two distinct eolian systems that are bounded by a long-lived unconformity.
Braz. J. Geol.. Publicado em: 11/11/2019
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3. First record of Acanthocephala parasites eggs in coprolites preliminary assigned to Crocodyliformes from the Adamantina Formation (Bauru Group, Upper Cretaceous), São Paulo, Brazil
Abstract Abstract: This study presents the oldest record of Acanthocephala parasite eggs in coprolites preliminary assigned to Crocodyliformes, recovered in the region of Santo Anastácio Municipality, Southwestern São Paulo State. For this, a paleoparasitological investigation was carried out on 53 mineralized coprolites (complete or fragmented), with roun
An. Acad. Bras. Ciênc.. Publicado em: 06/05/2019
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4. Cretaceous carbonatites of the southeastern Brazilian Platform: a review
ABSTRACT: This paper reviews general aspects of alkaline-carbonatitic rocks of Brazilian, Paraguayan and Bolivian terrains. Although 30 such occurrences are known in literature, only the major ones have been thoroughly investigated. The carbonatites are of Cretaceous age, with two well-defined Lower Cretaceous and Upper Cretaceous generation episodes. A clea
Braz. J. Geol.. Publicado em: 2018-06
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5. Upper Cretaceous weakly to strongly silica-undersaturated alkaline dike series of the Mantiqueira Range, Serra do Mar alkaline province: Crustal assimilation processes and mantle source signatures
ABSTRACT: Three series of alkaline dikes are characterized in a restricted area of the Mantiqueira Range: a weakly silica-undersaturated series (normative ne < 7), of potassic character, represented by basanite, tephrites, alkali basalts, basaltic trachyandesites, phonotephrites, tephriphonolites, and trachyandesites, an intermediate series (7 > normative ne
Braz. J. Geol.. Publicado em: 2018-06
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6. New plant fossils from the Lower Cretaceous of the Parnaíba Basin, Northeastern Brazil: Southern Laurasia links
ABSTRACT: This study reports on the presence of a diverse set of gymnosperm and angiosperm macrofossils from the Codó Formation, Parnaíba Basin, whose assemblage was previously known only by the occurrence of pollen grains, spores, wood fragments, leaves and roots associated with Nympheaceae. In the Brejo municipality, northeastern Maranhão State, marl le
Braz. J. Geol.. Publicado em: 2018-01
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7. New azhdarchoid pterosaur (Pterosauria, Pterodactyloidea) with an unusual lower jaw from the Portezuelo Formation (Upper Cretaceous), Neuquén Group, Patagonia, Argentina
ABSTRACT A new azhdarchoid pterosaur from the Upper Cretaceous of Patagonia is described. The material consists of an incomplete edentulous lower jaw that was collected from the upper portion of the Portezuelo Formation (Turonian-Early Coniacian) at the Futalognko site, northwest of Neuquén city, Argentina. The overall morphology of Argentinadraco barrealen
An. Acad. Bras. Ciênc.. Publicado em: 25/09/2017
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8. A new saurolophine hadrosaurid (Dinosauria: Ornithopoda) from the Upper Cretaceous of Shandong, China
ABSTRACT A new saurolophine hadrosaurid, Laiyangosaurus youngi gen. et sp. nov. is described and phylogenetically analyzed based on several cranial elements from the Jingangkou Formation, Wangshi Group, Upper Cretaceous of Laiyang, Shandong, China. Laiyangosaurus youngi differs from other members of the saurolophine clade on the basis of a number of autapomo
An. Acad. Bras. Ciênc.. Publicado em: 31/08/2017
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9. Micromorphology of Paleosols of the Marília Formation and their Significance in the Paleoenvironmental Evolution of the Bauru Basin, Upper Cretaceous, Southeastern Brazil
ABSTRACT Deduction of associated paleoenvironments and paleoclimate, definition of the chronosequence of paleosols, and paleogeographic reconstruction have become possible through the application of micromorphology in paleopedology. Micromorphology has also been useful in recognition of weathering processes and definition of minerals formed in succession. In
Rev. Bras. Ciênc. Solo. Publicado em: 13/02/2017
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10. Pedodiagenetic Characterization of Cretaceous Paleosols in Southwest Minas Gerais, Brazil
ABSTRACT The influence of post-burial geological processes on preserving pedogenic properties has great importance in identifying ancient paleosols both in the field and in a laboratory. However there are not many publications that focus on characterizing paleosol diagenesis. As temperature and pressure progressively increase, evidence of pedogenesis is modi
Rev. Bras. Ciênc. Solo. Publicado em: 06/02/2017
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11. Paralavas in the Cretaceous Paraná volcanic province, Brazil - A genetic interpretation of the volcanic rocks containing phenocrysts and glass
ABSTRACT The occurrences of glassy rocks containing long and curved phenocrysts in the Paraná volcanic province, South America, are here interpreted as paralavas. The large number of thin (0.1-0.5 m) dikes and sills of glassy volcanic rocks with hopper, hollow or curved, large crystals of clinopyroxene (up to 10 cm), plagioclase (up to 1 cm), magnetite and
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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12. New turtle egg fossil from the Upper Cretaceous of the Laiyang Basin, Shandong Province, China
Uma nova espécie de ovo de tartaruga fóssil foi estabelecida: Emydoolithus laiyangensis oogen. et oosp. nov. Esta possui forma elíptica, uma casca rígida e outras características da casca que diferem dos demais ovos fósseis de quelônios conhecidos, todos de forma arredondada. Trata-se da segunda espécie de ovo fóssil de quelônio encontrado no Cret�
An. Acad. Bras. Ciênc.. Publicado em: 2013-03