A New Dinoflagellate from the Late Cretaceous of the Colorado Basin, off Shore Argentina

Abstract

This paper introduces a new dinoflagellate cysts species from the Late Campanian ? Early Maastrichtian horizons of the Colorado Basin: Andalusiella guersteiniae sp. nov. It is a relatively large, fusiform organic-walled cyst, whose apical horn is longer than its antapical one, and has a smooth endophragm that is markedly thicker than the periphragm; a peridinioid paratabulation is suggested by the intercalary 2a hexa iso-deltaform archeopyle, the paracingulum and the parasulcus. The age of this new species is determined by associated palynomorphs, foraminifers and nannoplankton, but also by radiometric dating.