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

GULER, VERÓNICA; GUERSTEIN, RAQUEL; CASADIO, SILVIO

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2005 vol. 42 p. 219 - 228

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 exhibits the periphragm covered with spines. Palaeocystodinium pilatum sp. nov. presents a periphragm densely covered with fine, flexous, hairlike projections, shortening towards the end of the horns and a finely granulate endopragm. The large peridinialean Caligodinium perforatum sp. nov. shows the hipocystal archeopyle typical for the genus, with a simple triplacoid opercular piece and a microfoveolate autophragm surrounded by a perforate floculent cloak. Spiniferites (Hafniasphaera) australis sp. nov. differenciates from the other species of the subgenus Hafniasphaera by the presence of a distinctive anterior ventral process emerging from the junction of the 1’, 4’, 6’’ and as paraplates. These new species characterize the assemblages from deposits related to the South Atlantic transgression occurred during the Maastrichtian at the southermost part of Argentina