FAUNA OF ARABIA 23: 435–468 Date of publication: 15.07.2007 Review of the taxonomy of the spiny-tailed lizards of Arabia (Reptilia: Agamidae: Leiolepidinae: Uromastyx) Thomas M. Wilms and Wolfgang Böhme A b s t r a c t : Currently six species of the genus Uromastyx (Reptilia: Agamidae: Leiolepidinae), representing three phylogenetic lineages, are known to occur in Arabia: Uromastyx aegyptia, U. benti, U. leptieni, U. ornata, U. thomasi and U. yemenensis. The present paper gives an overview of the taxonomy of these lizards and presents new data on the morphology and ecology of Uro- mastyx leptieni. Authors’ addresses: Thomas M. Wilms, Reptilium – Terrarien- und WüstenZoo, Werner-Heisenberg-Str. 1, 76829 Landau, Germany; e-mail: thomasmwilms@ yahoo.de Wolfgang Böhme, Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 160, 53113 Bonn, Germany; e-mail: W.Boehme. ZFMK@uni-bonn.de Authors’ addresses: Thomas M. Wilms, Reptilium – Terrarien- und WüstenZoo, Werner-Heisenberg-Str. 1, 76829 Landau, Germany; e-mail: thomasmwilms@ yahoo.de Wolfgang Böhme, Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 160, 53113 Bonn, Germany; e-mail: W.Boehme. ZFMK@uni-bonn.de INTRODUCTION Spiny-tailed agamas are small to medium-sized, ground- or rock-dwelling lizards. Most species reach a maximum length of 25-50 cm, and only species of the Uromastyx aegyptia group can reach a total length of up to 70 cm or more. The animals have a bulky, depressed body and strong, short limbs. The tail is covered by spiny scales, arranged in distinct whorls. The tympanum is visible. None of the species has a nuchal or dorsal crest or a gular pouch or fan. Only a transverse fold at the throat is present (gular fold). Body scales are small and mostly homogenous, but some species have enlarged tubercular scales on the body and/or limbs. The main diagnostic character of the genus is the highly specialised tooth-like bony structure replacing the incisor teeth in the upper jaw in adults. This transformation of the premaxillary bone to a tooth-like structure is an autapomorphy of the genus Uromastyx, convergent in Sphenodon, which has also a convergently acrodont dentition. Owing to morphological, ethological and ge- ������� ������ ��� � ����� ����� ������ ������� ������ ) ������� : ��������� : Leiolepidinae: Uromastyx ( ���� ��������� ����� ����� ���� : ����� ���� ������� ������ ��� � � ���� �� ����� Uromastyx ) ������� : ��������� : Leiolepidinae ( � ����� � ���� ������ ����� Uromastyx aegyptia U. benti, U. leptieni, U. ornata, U. thomasi, � U. yemenensis . ����� ������� ������ ����� ����� ����� ����� ������ ��� ������ ������ ����� ���� Uromastyx leptieni .