Strougo, A. & Elattaar, A. A. (2012): Restudy of the Eocene echinoid Schizaster vicinalis var. Libycus Fourtau, 1908 and Biostratigraphic evaluation of the species of Schizaster in the Mokattamian Stage (Middle and Late Eocene) of Egypt. Egyptian Journal of   Paleontology, Vol. 12, pp. 1-16, pl.1, 2, 1 text-fig.
ABSTRACT Schizaster vicinalis var. libycus Fourtau, 1908 differs from true vicinalis by a number of important characters and should be treated as a separate species, here called Schizaster (Paraster) libycus. Contrary to previous belief there is no unequivocal evidence for the occurrence of Schizaster vicinalis in the Mokattamian rocks of Egypt; Egyptian forms assigned to this species need critical revision. ... Read more