Fungal Palynomorphs from the Cullen Formation (Miocene), Tierra del Fuego, Southern Argentina.

GARCÍA MASSINI, J.L.

Madison, Wisconsin, USA

Congreso; 96th Botanical Society of America meeting; 2002

  Abstract The aim of this study was to analyze the diverse fungal palynomorphs present in the Cullen Formation (Miocene), included in the Austral Basin, along the NE coastal region of the Isla Grande in Tierra del Fuego, Argentina. Fifty four form genera including eighty species of fossil fungal spores were recognized. In addition nine genera and eight species of fungal fruiting bodies, most belonging to the extant Microthyriaceae (Ascomycota), are present. Many spores, fruiting bodies, and other fungal structures, could not be assigned to any known extant or fossil genera. Of the total fungal palynomorphs, 34 genera including 74 species of spores, as well as 5 genera and 4 species of fruiting bodies, are described for the first time in Argentina, enlarging their geographical distribution, and in some cases their stratigraphic occurrence. Several taxa suggest a tropical to subtropical paleoenvironment with high humidity indexes. The presence of certain fungal spores (Ornatisporites inaequalis, Brachysporisporites tenuis) and fruiting bodies (Microthyriella diporata, Phragmothyrites kiandrensis), provide a biostratigraphic index suggesting a Miocene age for the Cullen Formation. Both paleoenvironmental and biostratigraphic conclusions are coincident with those based on other palynological and sedimentary evidence.