Resumen de Dinoflagellate Cysts and Acritarchs from the Middle and Upper Jurassic of the Neuquen Basin, Argentina

M.E. Quattrocchio, W. A. S. Sarjeant

• The stratigraphic distribution of Callovian to Upper Tithonian dinoflagellates from a sequence in the Neuquén Basin, Argentina, is evaluated. Five new species (Aptea notialis, Dissiliodinium volkheimeri, Diacanthum argentinum, Paraevansia mammilata and Pilosidinium cactosum), one new subspecies (Lithodinia jurassica (Eisenack) subsp. reburrosa) and one new variety (Dichadogonyaulax culmula (Norris) var. curtospina) are recognized. In addition, an emended diagnosis is presented for Hystrichosphaerina newquina Quattocchio and Volkheimer. Correlation with dinoflagellate zones from northwest Europe is made, utilising comparisons with first appearances and abundances of selected cysts in the Neuquén Basin. A preliminary scheme of dinoflagellate parazones for the Argentinian Jurassic is formulated, to facilitate future correlations.