A freshwater ichthyofauna from the late Eocene Birket Qarun Formation, Fayum, Egypt

Abstract

ABSTRACT A collection of fossil fish teeth and other elements from Eocene deposits on the northshore of Birket Qarun, Fayum Depression, Egypt, is reported. This collection adds significantly to our knowledge, as it consists of material that was screened from the sediments, allowing collection of small teeth that represent taxa not previously reported from the Fayum. Previous collections from these sediments have concentrated on larger remains that generally represent elasmobranchs, which are marine species from deposits lower in the section. Most of this material, collected by screening at the Birket Qarun 2 (BQ-2) locality, represents fully freshwater fishes. It includes the first record of the mormyrid Gymnarchus in the Fayum Depression, which represents the oldest record for this group, known previously only from the late Miocene or younger deposits. Similarly, Mochokidae (Siluriformes) and Hydrocynus (Alestidae) remains from the site are the oldest record of these taxa. Other taxa recovered are the osteichthyans Polypterus (Polypteriformes), Protopterus (Dipnoi), and Parachanna (Channidae), and the chondrichthyans Hypolophodon cf. H. malembeensis (Dasyatoidea incert. fam.), Rhinoptera sherborni (Rhinopteridae), and Coupatezia wousteri (Dasyatoidea incert. fam.). A new ray, Coupatezia attiai, n. sp., Cook, is also described. These fishes confirm the freshwater influence at locality BQ-2 in the Birket Qarun Formation.