FIRST TITHONIAN RECORD OF PERFORATED PEDIASTRUM MEYEN S.L. SPECIES WITHIN EARLY–DIAGENETIC CARBONATE CONCRETIONS FROM THE VACA MUERTA FORMATION, NEUQUÉN BASIN, ARGENTINA. IMPLICATIONS FOR THE PALYNOLOGICAL ANALYSIS OF FINE-GRAINED ROCKS

The perforated Pediastrum Meyen s.l. species are recorded for the first time in basal levels of Tithonian Vaca Muerta Formation, extending its stratigraphical record to ages as old Late Jurassic times. Based on ecological requirements simplex var. clathratum and P. biwaense, previously warm paleoclimatic conditions suggested by Neuquén Basin, reinforced. co-occurrence different mechanisms that interacted during transport, accumulation, early diagenesis these sediments their organic content would have allowed excellent preservation species.