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

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.

ACKNOWLEDGMENTS

We are grateful to K. Seymour (ROM), J. Snoeks (MRAC), B. Brown (AMNH), D. Nelson (UMMZ), and S. Laframboise (CMN) for lending Recent comparative material, and to M. Newbrey (University of Alberta) for giving access to comparative specimens in his care. We thank K. Soliman and A. Swedan and other staff of the Egyptian Geological Survey and Mining Authority for supporting and facilitating ongoing paleontological fieldwork in the Fayum Depression. Thanks to M. Templin for help with translations, and M. Labbé (University of Alberta, Department of Earth and Atmospheric Sciences) for thin sectioning. The Fayum project has been funded by the National Science Foundation (BCS 0416164 to E.L.S. and E. Seiffert and BCS 0819186 to E. Seiffert), the Leakey Foundation, and Gordon and Ann Getty. This research was supported by NSERC Discovery grant 327448 to A.M.M. Our thanks to O. Otero, C. Underwood, and T. Grande for reviews and editorial help that improved the manuscript. This is DPC publication no. 1175. This paper is dedicated to the memory of our co-author, Yousry Attia.