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Zavattieri,Ana María; Mego,Natalia. |
Well-preserved spore-pollen assemblages from the type locality of the Paso Flores Formation, in the Estancia Paso Flores area, on the southeastern side of the Limay River, northern Patagonia, Argentina, are presented in this contribution. In this area, the Paso Flores Formation is exposed along the boundary between the Río Negro and Neuquén provinces; it consists mainly of conglomerates, sandstones and mudstones and contains remains of the Dicroidium Flora. The facies associations suggest gravelly to sandy braided river systems as the main depositional environments of the lower to middle sections of the unit outcropping in this region. The palynofloral assemblages contain 48 species of bryophytic and pteridophytic spores, 30 species of gymnospermous pollen... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Palynology; Upper Triassic; Paso Flores Formation; Patagonia; Argentina. |
Ano: 2008 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0002-70142008000200018 |
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Pires,Etiene F.; Guerra-Sommer,Margot. |
The anatoical description of silici?ed Gymnospermae woods from Upper Triassic sequences of southernmost Paraná Basin (Brazil) has allowed the identi?cation of a new taxon: Sommerxylon spiralosus n.gen. et n.sp. Diagnostic parameters, such as heterocellular medulla composed of parenchymatous and sclerenchymatous cells, primary xylem endarch, secondary xylem with dominant uniseriate bordered pits, spiral thickenings in the radial walls of tracheids, medullar rays homocellular, absence of resiniferous canals and axial parenchyma, indicate its relationship with the family Taxaceae, reporting on the first recognition of this group in the Triassic on Southern Pangea. This evidence supports the hypothesis that the Taxaceae at the Mesozoic were not con?ned to the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fossil wood; Taxacean affinity; Upper Triassic; Paraná Basin. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300013 |
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