Agamid lizard (Agamidae: Uromastycinae) from the lower Oligocene of Egypt

Abstract

Agamid lizards are currently found in Africa, Asia, the eastern Mediterranean region and Australia. Together with the Chamaeleonidae and some extinct basal forms, they comprise the Acrodonta, lizards with acrodont dentition. The Acrodonta have been suggested to have a Gondwanan origin, with the oldest members found in the Triassic of India. The first agamids are known from the Late Cretaceous of Asia, and the group is widely distributed in the northern hemisphere throughout much of the Paleogene. However, the fossil history of Acrodonta on the Afro-Arabian plate is extremely limited: a single jaw fragment bearing acrodont dentition, possibly attributable to Agamidae, has been reported from the Paleogene of Morocco, and material identified as agamid was reported from the Oligocene of Oman. We here add to the African record the first clear evidence of Agamidae, represented by several jaws with attached teeth from earliest Oligocene deposits of the Jebel Qatrani Formation in the Fayum Depression, Egypt. Characters of the teeth, including very rounded labial surface, shearing edges concave lingually, shearing tip crescentic and accessory cusps absent, are similar to those of Uromastyx. Species of Uromastyx currently inhabit the Saharan and Somalian regions of Africa and adjacent Arabia.

Keywords:

• Acrodonta
• North Africa
• squamate

Acknowledgements

We are grateful to K. Seymour of the Royal Ontario Museum, A. Resetar of the Field Museum, and G. Schneider and R. Nussbaum of the Zoology Museum of the Universtiy of Michigan for lending recent comparative material, to R. Nydam (Midwestern University) for helpful discussion and advice, S. Moody for providing information, and to E. Snively (University of Alberta) for assistance with scanning. Thanks to N. Dale-Skey (ICZN) for providing a copy of Opinion 565, and J.S. Nelson (U of Alberta, former ICZN member) for helpful discussions and interpreting the zoological code. We are also grateful to Biodiversity Heritage Library for providing free access to a wealth of older publications on their web site. We thank H. Hamouda and other staff of the Egyptian Geological Survey and Mining Authority for supporting and facilitating ongoing paleontological fieldwork in the Fayum Depression. The Fayum project has been funded by the National Science Foundation (grants BCS 0416164 to E.L. Simons and E. Seiffert and BCS 0819186 to E. Seiffert), the Leakey Foundation, and Gordon and Ann Getty. Research support for this project was funded by the National Sciences and Engineering Research Council of Canada (Discovery grant 327448 to A.M. Murray) and Canadian Foundation for Innovation (Leaders Opportunity Fund grant 16259 to A.M. Murray). Thanks to J.C. Rage and R. Nydam for helpful reviews that improved the manuscript. This is DPC contribution # 1158.