ESTUDIO PALEOBOTANICO y TAFONOMICO EN LA FORMACION PASO FLORES (TRIASICO SUPERIOR), EN EL CAÑADON DE PANCHO, NEUQUEN, ARGENTINA

Abstract

Two Triassic plant assemblages found at Cañadón de Pancho locality, belonging to Paso Flores Formation, are characterized as two different taphocoenosis belonging to different sedimentary facies. The lower burial contains fossil plants belonging to Corystospermales, Cycadales and Coniferales, as shrubs or trees; this facies is associated with lacustrine environments. The characteristics of the plant remains, suggest that the fossils underwent a short transportation and the parent communities grew in the area sourrounding the lake. The upper burial is an autochthonous or hipautochthonous taphocoenosis, dominated by the herbaceous Scleropteris grandis n. sp. and related to a fluvial environment. Although of a slender structure, complete fronds of Scleropteris grandis n. sp. suggest fosilization in situ. This taxon grew on top of bars and was dominant over other taxa, as Sphenabaiera robusta, Czekonowskia rigali and Cordaicarpus sp. that occur occasionally, probably coming from neighbouring areas. The chronostratigraphic analysis based on fossil plants, suggests a late Upper Triassic age.