WHAT IS NUMMULITES GIZEHENSIS (FORSKAL) S.STR ? QU'EUE INTERPRETATION POUR NUMMULITES GIZEHENSIS o (FORSI«L) S.STR?

Abstract

ABSTRACT. - Nummulites gizehensis (Late Lutetian) from the Giza Pyramids Plateau named by Forskal and fully described by de la Harpe, is here described and also recorded from Gehel EI-Nour, Villageof Dahaiba, east of Beni Suef, Nile Valley. The ancestor of N. gizehensis (FonsKAL)s.str. is newly erected as N. praegizehensis n.sp. (Middle Lutetian). By tracing the evolutionary development of this lineage it is noticed that progressive tigbt coiling in the microspheric generation exists while only the primary whorl in the megalospheric generation is laxer than the outer tight whorls. N. gizehensis perhaps is the terminal species in the N. gizehensis s.str, lineage characteristic for the Upper Lutetian after which it was extinct. The phyletic relation between N. gizehensis s.str. and N. lyelli as proposed by some authors needs revision and verification.