Taxonomy and biostratigraphy of Middle-Upper Jurassic ostracodes from Gebel Maghara area, Northern Sinai, Egypt.

Abstract

Study of the Jurassic Bir Maghara, Safa and Masjid Formations in the area of Gebel Maghara for ostracodes yielded 27 species assigned to 17 genera. Of these, the species which are not known in previous literature have been described. Morphologic and taxonomic comments and comparisons have been made also to the already known species wherever necessary. The ostracode record in the study area indicates a Bajocian age to the major part of the Bir Maghara Formation, a Bathonian age to the uppermost part of the Bir Maghara Formation, the Safa Formation and the lower part of the Masajid Formation and a late Bathonian - ?Callovian age to the uppermost part of the Masajid Formation. The recorded ostracode assemblages are dominated by shallow marine species; however, some levels in the Bajocian part of the Bir Maghara Formation and the Bathonian part of the Masajid Formation yield Darwinula cf. techoutensis which indicates a fresh water influence during the time of deposition of these levels.