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Acarinina sibaiyaensis is a very distinctive and short-lived planktonic foraminiferal taxon that is restricted to the temporally short Carbon Isotope Excursion (CIE) interval characteristic of the Paleocene-Eocene Thermal Maximum (PETM) event. It is confined to the planktonic foraminiferal Zone E1 which in southern Egypt corresponds to the Dababiya Quarry Member (DQM). This member yields a complete record of the biotic changes induced by the intense warming during the basal Eocene . Although this distinctive taxon is widely distributed throughout the tropic to the temperate regions, its morphologic changes and phylogenetic relations during the CIE/PETM interval have not yet been documented. The present study discusses and documents the morphologic changes which affected the short-lived Ac. sibaiyaensis probably caused by the extreme warming during the very brief (175–200 ka) CIE/PETM interval in southern Egypt. These morphologic variations are particularly well developed in the middle phosphatic phase (Beds 2 and 3 of the DQM), in which the CIE curve shows its maximum negative shift. The origin, morphology, wall texture, coiling direction and their changes during ontogeny and evolution of Ac. sibaiyaensis during the CIE-PETM interval at Qreiya, Gebel Abu Had, northeast Qena (southern Nile Valley) and Darb Gaga (southeast of Kharga Oasis, southern Western Desert) are described, interpreted and illustrated. During the PETM, numerous intraspecific varieties of Ac. sibaiyaensis are recorded. Several evolutionary lineages are delineated; some of them stay within the morphologic range of Ac. sibaiyaensis, whereas others lead to other excursion taxa i.e. Acarinina africana and Morozovella allisonensis. In addition, forms transitional to taxa which appear in younger horizons than the PETM (younger than Zone E1) are recorded, described and illustrated.

Non-marine vertebrates, including many crocodyliform clades, remain poorly documented from uppermost Cretaceous deposits of Africa. Recent exploratory fieldwork in the Upper Cretaceous (middle Campanian) Quseir Formation exposed around Dakhla Oasis (Western Desert of Egypt) has revealed new fossils from continental and marginal marine settings that include abundant crocodyliform remains. In particular, materials of an enigmatic crocodyliform, Wahasuchus egyptensis gen. et sp. nov., represented by both cranial and postcranial remains, suggest the presence of a novel southern Tethyan crocodyliform assemblage from northern Africa during the Late Cretaceous. Materials recovered of this taxon thus far include fragmentary portions of the skull and mandible, amphicoelous dorsal vertebrae, and fragmentary appendicular remains. This form is distinguished by a number of unique features including a domed platyrostral skull; a strongly festooned lateral margin of the maxilla with two waves of tooth enlargement; a deep, sculptured fossa at the base of the postorbital bar; a jugal with an anterior process that is at least three times broader than the posterior process; an orbital margin dorsally overlapping the lateral temporal fenestra; a supraoccipital with a distinct medial tuber and associated ventral fossa; and a robust straight dentary with contribution of the splenial to the symphysis. This new form suggests a potentially unique Late Cretaceous assemblage from northern Africa, markedly different from better-known Late Cretaceous crocodyliform assemblages of South America and Madagascar, or from earlier (pre-Turonian) deposits in Africa. This pattern may reveal a distinct regional fauna along the southern Tethys, or potential Cretaceous relationships with Eurasian neosuchian-dominated assemblages.

Paleontological studies on the Upper Paleocene-Lower Eocene succession at Darb Gaga, southeastern Kharga Oasis, Western Desert, Egypt document the changes associated with the Paleocene-Eocene Thermal Maximum (PETM), such as 1) a radical alteration of the relative and absolute abundance of planktonic foraminifera; 2) a massive occurrence of the excursion planktonic foraminiferal taxa; 3) a widespread deposition of calcarenite yielding atypical (extremely high) faunal abundance associated with the younger phase of warming; and 4) a concentration of coprolites associated with the middle phase of warming. We also document the Lowest Occurrence (LO) of dimorphic larger benthic and excursion foraminifera during the earlier phase of warming at Darb Gaga, as recorded in Bed 1 of the Dababiya Quarry Member. The absence of these faunas in Bed 1 at Dababiya (the GSSP for the P/E Boundary) is likely to be due to both intense deficiency in dissolved oxygen and massive carbonate dissolution. Only remains (fish remains) of faunas that can tolerate the toxicity produced by low oxygen conditions are found in the stratigraphic record of this (oldest) phase at Dababiya. The Dababiya Quarry Member (DQM) at Darb Gaga reflects the unfolding of the sedimentary and biotic changes associated with the PETM global warming at, and following, the Paleocene/Eocene boundary on the southern Tethys platform. The changes began with a rapid increase in bottom and “intermediate” water temperature. The temperature increase was accompanied by removal of oxygen during the early and middle stages of warming. This led to the absence of both subbotinids and calcareous benthic foraminifera in the early and second coprolite-bearing phases (Beds 2 and 3 of the DQM). Dissolution seems to have no role during these stages as shown by the unusual abundance and good preservation of the warm-tolerant Ac. sibaiyaensis. This species reaches its maximum abundance in Bed 2 where it exhibits a broad range of size (63–250 μm) and shape that probably reflect optimal growth under the warmest water conditions. Thus, we infer that temperature and dissolved oxygen content of the sea-water were the main factors controlling the distribution pattern(s) of the microplankton and microbenthos during the PETM.

The Campanian and Maastrichtian stages are very poorly documented time intervals in Africa's record of terrestrial vertebrate evolution. Upper Cretaceous deposits exposed in southern Egypt, near the Dakhla and Kharga Oases in the Western Desert, preserve abundant vertebrate fossils in nearshore marine environments, but have not yet been the focus of intensive collection and description. Our recent paleontological work in these areas has resulted in the discovery of numerous new vertebrate fossil-bearing localities within the middle Campanian Qusier Formation and the upper Campanian-lower Maastrichtian Duwi Formation. Fossil remains recovered from the Campanian-aged Quseir Formation include sharks, rays, actinopterygian and sarcopterygian fishes, turtles, and rare terrestrial archosaurians, including some of the only dinosaurs known from this interval on continental Africa. The upper Campanian/lower Maastrichtian Duwi Formation preserves sharks, sawfish, actinopterygians, and marine reptiles (mosasaurs and plesiosaurs). Notably absent from these collections are representatives of Mammalia and Avialae, both of which remain effectively undocumented in the Upper Cretaceous rocks of Africa and Arabia. New age constraints on the examined rock units is provided by 23 nannofossil taxa, some of which are reported from the Duwi Formation for the first time. Fossil discoveries from rock units of this age are essential for characterizing the degree of endemism that may have developed as the continent became increasingly tectonically isolated from the rest of Gondwana, not to mention for fully evaluating origin and diversification hypotheses of major modern groups of vertebrates (e.g., crown birds, placental mammals).