Paleontology of the Lagarcito formation (lower Cretaceous), San Juan Province, Argentina.

The first paleontological records from the Lagarcito Formation (Albian) in the eastern side of the sierra de Guayaguas (La Yesera Sur section), south-eastern San Juan Province, central-western Argentina, are presented. Although several lake episodes have been detected, only three of them have yielded abundant palynologic and paleontologic remains. Eight chlorophyte algal species, three conchostracan species and eleven non-marine ostracod species, are described and illustrated. The associations indicate a shallow lacustrine environment, that was initially rich in nutrients and with high levels of evaporation, as demonstrated by interstratified gypsum towards the top of each lacustrine episode. Two of the conchostracan species described are new: Dendrostracus lagarcitoensis Gallego sp. nov. and Pseudestherites rivarolai Gallego sp. nov.