Palaeoichthyofaunas from the Lower Oligocene and Miocene of the Arabian Plate: palaeoecological and palaeobiogeographical implications

Abstract

The ichthyofaunas of Thaytiniti and Taqah (Lower Oligocene, Sultanate of Oman) and As-Sarrar (Burdigalian, Saudi Arabia) are studied with particular emphasis on palaeoenvironmental and palaeobiogeographic approaches. The fossil fish reported from these sites include freshwater and marine taxa: Osteoglossiformes Osteoglossidae ( Heterotis sp.); Cypriniformes Cyprinidae (? Barbus sp.); Characiformes Hepsetidae ( Hepsetus sp.); Characidae Alestinae (two types); Siluriformes Bagridae ( Bagrus sp.), Clariidae [Clariidae indet., Clarias ( Clarias)], Mochokidae ( Synodontis sp.); Perciformes Latidae [ Lates ( Lates) sp. cf. Miloticus, L. niloticus]; Sparidae (four morphotypes); Tetraodontiformes Tetraodontidae (Tetraodontidae indet.) and Diodontidae (Diodontidae indet.). Study of the habitat of the Recent taxa and fossil relatives, nature of preservation, biotic associations and sedimentological features are integrated to ascertain palaeoenvironmental scenarios. An analysis of the ecology of the ichthyofauna and its evolution since the Oligocene is studied in relation with the African ichthyofaunas. The palaeobiogeographical study focuses on the exchanges and direction of migrations of freshwater fish between Asia and Africa at the time of the Early Miocene terrestrial connection between the two continents.