Middle-Late Jurassic Bennettitales from Deseado Massif, Patagonia Austral, Argentina

ZAMUNER, A.; SAGASTI, A.; CHANNING, A.; GUIDO, D.

Lujan

Encuentro; Reunión Anual de Comunicaciones de la Asociación Paleontológica Argentina; 2011

In this contribution we present a preliminary analysis of the fossil record of Bennettitales in the Deseado Massif during Middle-Late Jurassic, based on the study and comparisons of taphofloras recovered from several localities: Flecha Negra (FN), Bajo Pellegrini (BP), San Agustín (SA) and Gran Bajo de San Julián (SJ). Biodiversity of the group is represented by leaves, including Dictyozamites Oldham et Morris, Otozamites F. Braun, Pterophyllum Brongniart and Zamites Brongniart. The clade does not have a uniform distribution across the Deseado Massif, being dominant in two floras (SA and BP); whilst at FN and SJ it appears only as a secondary element. Dictyozamites is the dominant genus in SA and BP floras with 8 spp. and is apparently absent in FN and SJ. Pterophyllum, on the other hand, seems to be the poorest represented genus, with only one species. The analysis of the taphofloras shows a high endemism at species level.