TAPHONOMIC CONDITIONS AND ASSESSMENT OF THE LATE CRETACEOUS VERTEBRATES BEARING SITES IN THE WESTERN DESERT, EGYPT

Abstract

The detailed stratigraphical field relations and taphonomic conditions and assessment of the Upper Cretaceous vertebrate bearing horizons in Western Desert of Egypt were investigated in the three sites; Campanian Quseir Formation, Kharga Oases, Maastrichtian Ammonite Hill member of Dakhla Shale, Abu Minqar and Lower Cenomanian Bahariya Formation in Gebel El Dist, Bahariya Oases. It was found that the most important taphonomic factors controlling the preservation state of vertebrate fossils in the selected sites are rate of transportation and sedimentation as well as bio-erosion and diagenetic events of the bearing sediments. A comparative study of these factors was achieved between the investigated vertebrates bearing sites. The study indicated that the vertebrate fossils in Bahariya and Kharga Oases are more preserved and less abraded than these in Abu Minqararea. Generally, the study vertebrate fossils that yielded in sandstones have better preserved state than other lithological types. Furthermore, the deposition in low rate of transportation and high rate of sedimentation give the vertebrate carcasses good opportunity for the rapid burying with articulated and semi articulated elements, consequently better preservation state. Due to the importance of the vertebrate bearing low topographic sites in the Western Desert, its highly recommended to carry out serious and decisive mitigation for the protection against negative impacts that caused by human activities (e.g. illegal land reclamation and ecotourism) which leading to groundwater rise in these lowlands.