New dinoflagellate cyst species from the Calafate Formation (Maastrichtian), Austral Basin, Argentina

GULER M. VERONICA; GUERSTEIN RAQUEL; CASADIO SILVIO

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2005 p. 419 - 428

0002-7014

The aim of this paper is to erect four new dinoflagellate cyst species from the Maastrichtian Calafate Formation, Austral Basin, Argentina. Andalusiella spinosa sp.nov. is strongly acrocavate and posesses a periphragm covered with spines. Palaeocystodinium pilatum sp.nov has a periphragm densely covered with fine, flexuous, hair like projections, shortening towards the end of the horns, and a finely granulate endophragm. The large peridinialean Caligodinium perforatum sp.nov. shows the hypocystal archeopyle typical for the genus, with a simple triplacoid opercular piece and a microfoveolate autophragm surrounded by a perforate flocculent calyptra. Hafniasphaera australis sp.no. is differentiated from other species of the genus Hafniasphaera by the presence of a distinctive anterior ventral process which emerges at the junction of paraplates 1´, 4´and as. These new species characterize the assemblages from deposits related to the South Atlantic transgression that occurred during Maastrichtian times at the southermost part of Argentina.