Early Cretaceous riparian vegetation in Patagonia, Argentina

GERARDO CLADERA; GEORGINA M. DEL FUEYO; LILIANA VILLAR DE SEOANE; SERGIO ARCHANGELSKY

Revista del Museo Argentino de Ciencias Naturales, Nueva Serie

Estudio Sigma S. R. L

Año: 2007 vol. 9 p. 49 - 58

1514-5158

Abstract: Early Cretaceous riparian vegetation in Patagonia, Argentina. An autochthonous plant assemblage found at the Bajo Grande locality, Anfiteatro de Ticó Formation, Baqueró Group, Early Aptian of Santa Cruz province, Argentina, is described. Sedimentological data show an alternation of sandstone and limestone, with recurrent fossil levels associated to a fluvial system. The frequent flood in areas close to the levee had an influence on the vegetation growing along the banks of the channels. A plant assemblage composed of Ricciopsis grandis nov. sp. (bryophyte), Adiantopteris tripinnata nov. sp., Schizaeaceae pinnules (ferns), and the gnetalean fructification Ephedra verticillata nov. sp. was found in this paleoenvironment. The taphonomical studies suggest that the plant assemblage was autochthonous, and it grew and was buried in an area near a levee. This result is congruent with environmental data provided by living representative of the fossil taxa analyzed.