Fig. 2From: A new species of Hypselaster (Echinoidea, Spatangoida) from the Middle Eocene Midawara Formation of the Eastern Desert, EgyptSubdivisions of the Mokattamian Stage and correlation with the standard stages (www.stratigraphy.org) (after Strougo 1985, 1986, 2008; Azab 1992) in the Nile Valley and the Fayum area, EgyptBack to article page