Clypeina tibanai, sp. nov. (Polyphysacea, Dasycladales, Chlorophyta), mid-Cretaceous green alga from the Potiguar Basin, Brazilian margin of the young South Atlantic Ocean - Granier, B. (The University of Kansas. Department of Ecology and Evolutionary Biology) ; Dias-Brito, D. (Universidade Estadual Paulista. Center for Geosciences Applied to Petroleum) ; Bucur, I. I. (Babeş-Bolyai University, Department of Geology and Center for Integrated Geological Studies)