الفهرس 
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Abstract
Macroinvertebrates have shown promise in analyzing paleoecosystems. Herein, the macroinvertebrate fossils were collected and identified from Saint Anthony section and east of the Wadi Irkas section in the northern scarp of the Southern Galala Plateau (Eastern Desert, Egypt). The Cenomanian-Turonian strata were subdivided into two distinctive formations from older to younger: Galala Formation and Wata Formation. Based on the vertical distribution of ammonites, five-ammonite biozones were recognized from the base to the top; Neolobites vibrayeanus Zone and Vascoceras cauvini Zone in the Upper Cenomanian, Vascoceras proprium Zone and Choffaticeras (Choffaticeras) segne Zone in the Lower Turonian, and Coilopoceras requienianum Zone in the Upper Turonian. In addition, the ammonite biozones were correlated both regionally and globally. Therefore, the Galala Formation was assigned to? Middle-Upper Cenomanian, while the Wata Formation was assigned to the Turonian.
Ninety-six macroinvertebrate species were identified and described in details. They include 53 bivalves, 20 gastropods, 14 echinoids, and 9 cephalopods. Quantitative analyses of their occurrence were used to identify major factors controlling their regional and global distribution. Non-metric Multidimensional scaling (nMDS) indicated that life habit, mobility level, and rock type are the major factors controlling the bivalves and echinoid distribution. Although the diversity and density of the fossil groups have punctuated patterns, a general trend of increasing diversity from the Cenomanian onwards was found. In contrast to the Cenomanian, mobile and infaunal bivalves have dominated the Turonian in a low-energy deeper marine environment with the oligotrophic regime. Lower diversity, the rarity of infaunal taxa in addition to abundant authigenic minerals (gluconate/pyrite) and oyster bivalves in the Cenomanian point to high-stress environment, where dysoxia at the sediment/water interface may exclude the infaunal taxa. In addition, Cenomanian echinoids have higher variability than Turonian ones.
Analysis of the geographic distribution of the fauna indicates no significant difference between the Middle East and regional provinces, but a significant difference with other mega-provinces. Only many bivalve taxa are cosmopolitan and were recorded globally. The Trans-Saharan Seaway may have provided a plausible migration way between the Middle East and Western Africa. In contrast, the high average sea floor-spreading rate of the Atlantic in the Cretaceous may clogged out dispersion to America.