A new species of claroteid catfish (Siluriformes: Claroteidae) from the Eocene of Egypt, (Africa) indicates continental differences in tempo of catfish evolution

ABSTRACT

We here describe a fossil catfish from freshwater deposits of the Jbel Qatrani Formation of the Fayum Depression, Egypt, as a new species of an extant genus, †Clarotes eocenicus, sp. nov., in the family Claroteidae. We base this placement on several cranial osteological features, including robust, laterally oriented anterior cornua of the mesethmoid, cranial fontanelle formed in mesethmoid and frontals but not extending into the parieto-supraoccipital, dermal ornamentation of small bumps concentrated on the posterior part of the skull, and supraoccipital crest short and broadly triangular. The material comes from the upper Eocene L-41 locality, which represents deposition in an oxbow lake environment. The new taxon, along with a previously described catfish from Tanzania, indicate that claroteid catfishes were established in both North and East Africa in the Eocene, and, unlike North America, Europe and Asia in which modern genera of catfishes were not present in the Eocene, at least two extant catfish genera had already evolved in the fresh waters of Africa by 45–35 million years ago.

ACKNOWLEDGMENTS

Our thanks to K. Seymour, Royal Ontario Museum, D. Nelson, University of Michigan Museum of Zoology, and C. Dillman and C. Dardia, Cornell University Museum of Vertebrates, for lending comparative recent material, to the late E. L. Simons and G. F. Gunnell, Duke University Primate Center, for lending fossil material, and to E. Barnard, Natural History Museum London, for access to material in her care. Particular thanks go to T. Argyriou (handling editor), G. Arratia, and K. Claeson for the many helpful comments they provided which improved the manuscript. We also thank the chairman of the Egyptian Geological Survey and Mining Authority, as well as the Director and staff of the Cairo Geological Museum, for supporting and facilitating paleontological fieldwork in the Fayum Depression.

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Funding

Fieldwork has been supported by a number of funding agencies and grants, including US National Science Foundation grant BCS 040416164 (to E. L. Simons). This research was supported by NSERC Discovery grant 327448 to A.M.M.