abuelkheir, g. abdelgawad, mk

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vertebrate remains such as shark teeth, dinosaur remains, and turtle plates. These sediments indicate ... crocodiles, shark teeth and coprolites. These layers areĀ ...
QUSEIR TESTUDINES REMAINS FROM THE LATE CRETACEOUS KHARGA AREA, SOUTH WESTERN DESERT, EGYPT 1

ABDELGAWAD, M. K. ; ABUELKHEIR, G. 1

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Geology Department, Faculty of Sciences, Cairo University, Giza, Egypt, [email protected]; Geology Department, Faculty of Sciences, New Valley University, New Valley, Egypt ;

Abstract Late Cretaceous stages are less documented periods in the Egyptian Testudines record. The Quseir Formation is a Campanian, Late Cretaceous site that mainly crops out in the southwestern Desert of Egypt. The locality comprises a clastic sequence of bioturbated mudstone and sandstone intercalations, which contain rare scattered and fragmented vertebrate remains such as shark teeth, dinosaur remains, and turtle plates. These sediments indicate a supratidal marsh environment. A recent expedition found turtle remains which had been collected from the Quseir Formation east of the Kharga area. The collected specimens are housed in the Geology Department, New Valley University. All the turtle remains are isolated plates; no cranial elements. However, four well-preserved, mostly complete shells, have been recovered. Three complete plastrons with a fragmentary carapace and one shell with both carapace and plastron have been collected from the compacted mudstone at the uppermost part of the formation. This area had been described previously as Late Cretaceous, Cenomanian period. At least two new Testudines genera are recovered from the Quseir Formation, Kharga area. The new taxa fill the missing evolutionary gap from the Late Cretaceous Testudines records in Egypt and generally in Africa.

Order Testudines Linnaeus, 1758 Subtribe Bothremydina Gaffney et al., 2006

WARM 002 Geological map for the south Western Desert, Egypt, showing the locality of the collected specimen (green Diamond) (after Said, 1990).

Order Testudines Linnaeus, 1758 Tribe Cearachelyini Gaffney et al., 2006

Location and Geology The present bone bearing layers of the southeast of Kharga is represented by the middle Campanian Quseir Formation (Youssef, 1957, Mahmoud, 2003 and Youssef, et al., 2011). Quseir Formation extends along the distance between Kharga and Baris, attaining a thickness varies between 60 and 80 m (Hendriks et al., 1984). According to Hermina (1990), Quseir Formation is divided into two members, Mut member and Hindaw member. The Mut member represents the lower part of Quseir Formation; it formed of about 30 m thick of red brick mudstone and grey fissile shale. The Hindaw member overlies the Mut member; it composed of about 30 m thick of glauconitic sandstone intercalated with grey siltstone thin layers (Hermina, 1990). From the nannoplankton studying (Sallam et al., 2016), Quseir Formation is referred to the late Campanian age. According to the studying of polymorphs and palynofacies (Mahmoud, 2003), Quseir Formation is deposited fluvio-lacustrine and restricted shallow marine environments. The present study area is located in the east of Gennah village (about 10 km south of Kharga oasis) where the upper most part of Quseir Formation is exposed. The lithologic exposure herein represents the ground of the study area without distinctive cliffs, showing the succession of Quseir Formation, except the human digging activities, exposing about 5 to 7 m thick of variegated shale intercalated with thin layers of sandstones, with fragments of turtles, crocodiles, shark teeth and coprolites. These layers are covered by about 2 m thick of grey purple mudstone, representing the bone bearing horizon of this locality. This layer is very rich by semi complete and separated turtle skeletons, partial skeletons and fragmented bones of sauropods, crocodile remnants and some fishbones, in addition to plant remains and cool. This layer is intercalated by medium to coarse grained, cross bedded sandstone fluvial lags. Small exposure of phosphate thin layer covers small part of the lower succession, very rich in shark teeth and fishbones. The sand sheets and the vegetation cover the large part of the study area.

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Conclusion The specimens can be considered as the first collected materials of Testudines from the Late Cretaceous Campanian, Quseir Formation in the south Western Desert of Egypt. The specimens are recorded the oldest known Testudines from Egypt. These sediments indicate a fluvio-lacustrine and restricted shallow marine environments. The new taxa fill the missing evolutionary gap from the Late Cretaceous Testudines records in Egypt and generally in Africa. Reference Gaffney, E.S., Tong, H. and Meylan, P.A., 2006. Evolution of the side-necked turtles: the families Bothremydidae, Euraxemydidae, and Araripemydidae; Bulletin of the American Museum of Natural History, no. 300. Hendriks, F., Luger, P., Kallenbach, H., Schroeder, J.H., 1984. Stratigraphical and sedimentological framework of the Kharga-Sinn El-Kaddab Stretch (Western and southern part of the upper Nile Basin), western desert, Egypt. Berl. Geowiss. Abh. A 50, 117-151 Hermina, M., 1990. The surroundings of Kharga, Dakhla, and Farafra Oases, in: Said, R. (Ed.), The Geology of Egypt. AA Balkema, Rotterdam, 259-292. Sallam, H. M., O'Connor, P. M., Kora, M., Sertich, J.W. J., Seiffert, R. E., Faris, M., Ouda, K., El-Dawoudi, I., Saber, S., El-Sayed, S., 2016. Vertebrate paleontological exploration of the Upper Cretaceous succession in the Dakhla and Kharga Oases, Western Desert, Egypt, Journal of African Earth Sciences 117 (2016) 223:234 Said, R., 1990. The geology of Egypt, pp.439-449. Mahmoud, M., 2003. Palynology and palaeoenvironment of the Quseir formation (Campanian) from central Egypt. J. Afr. Earth Sci. 36, 135-148. Youssef, M.I., 1957. Upper Cretaceous Rocks in Kosseir Area. Bull. Inst. Desert Egypt. 7, 35-54. Youssef, M., Sallam, H.S., Friedman, M., O'Connor, P., Sertich, J., 2011. A Saurodonid fish from the late Cretaceous of Dakhla Oasis, Western Desert, Egypt. Soc. Vertebr. Paleontol. 124.