Middle Miocene corals from Midyan area, Northwestern Saudi Arabia

Low-diversity scleractinian corals were described systematically from the Middle Miocene Wadi Waqb Member (Jabal Kibrit Formation) in the northwest of Saudi Arabia. The fauna comprises nine species belonging to nine genera and four families: Porites sp., Favites neglecta (Michelotti in D'Achiardi, 1868), Tarbellastraea reussiana (Milne-Edwards & Haime, 1850), Acanthophyllia ampla (Reuss, 1871), Solenastrea turonensis (Michelin, 1847), Thegioastraea roasendai Michelotti, 1871, Heliastraea oligophylla (Reuss 1871), Heliastraea sp., and Siderastrea miocenica Osasco, 1896. The identified corals were recorded previously from the Mediterranean basin, Portugal, France, Spain, Romania, Catalonia, Sardinia, Algeria, Egypt, Iran, Turin, Greece, Hungary, and Bosnia basins. The decreasing richness or diversity pattern of the fauna is attributed to the lack of possible exchange with zooxanthellate coral faunas of the Indo-Pacific after the late Burdigalian, due to the closure of marine seaways through the Middle East by emergent areas and northward rotation of the Arabian Peninsula.