Review of the Taxonomy of the Spiny-Tailed Lizards of Arabia (Reptilia: Agamidae: Leiolepidinae: Uromastyx)
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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. ������� ������ ��� � ����� ����� ������ ������� ������ (Leiolepidinae: Uromastyx :��������� :�������) ���� ��������� ����� ����� (Leiolepidinae :��������� :�������) Uromastyx ���� �� ����� � ������� ������ ��� � ������ ���� :���� .U. yemenensis � U. benti, U. leptieni, U. ornata, U. thomasi, Uromastyx aegyptia ���� ������ ����� � � ����� .Uromastyx leptieni ����� ������� ������ ����� ����� ����� ����� ������ ��� ������ ������ ����� ���� 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- 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. [email protected] 436 T.M. WILMS & W. BÖHME netic synapomorphies, butterfly agamas of the genusLeiolepis are considered to be the closest living relatives of spiny-tailed lizards and both genera are therefore placed in the subfamily Leiolepidinae (synonym: Uromastycinae) (PETERS 1971, MOODY 1980, BÖHME 1988, SCHMITZ et al. 2001, AMER & KUMAZawa 2005). Lizards of the genus Uromastyx occur in the desert belt of the Old World between 5°N and 35°N. Their range covers an enormous land mass, including northern Africa, the Middle East, Arabia, Iran, Iraq, Afghanistan, Pakistan and north-western India (Fig. 1). Today, 17 species are recognised, of which six species (with three additional subspecies) are native to Arabia (Kingdom of Saudi Arabia, Yemen, Sultanate of Oman, United Arab Emirates, Qatar and Kuwait (WILMS 2001, 2005; WILMS & SCHMITZ 2007). The species of spiny-tailed lizards currently known to occur in Arabia are: Uromastyx aegyptia (Forskål, 1775), U. leptieni Wilms & Böhme, 2000, U. benti (Anderson, 1894), U. ornata von Heyden, 1827, U. yemenensis Wilms & Schmitz, 2007 and U. thomasi Parker, 1930. They rep- resent three different phylogenetic groups, with species compositions listed below (WILMS 2001, WILMS & SCHMITZ 2007). Uromastyx habitats are generally characterised by high temperatures, low precipitation, sparse vegetation and marked seasonal changes (Plates 1-2). However, in the coastal regions of south and south-western Arabia (Asir and Hejaz Mountains, Hadramaut and Dhofar), Uromastyx habitats are more mesic because of the influence of the summer monsoon, resulting in high air moisture and elevated precipitation. These habitats are often well vegetated. Uromastyx species are mostly found on firm soil or on rock surfaces that provide shelter in the form of cracks and crevices. They also need, at least for part of the year, a sufficient amount of vegetation as a food source. Uromastyx live mainly in rocky desert and semi-desert habitats that are covered with rocks, scattered stones or gravel. Large continuous dune areas (erg) with drifting sand do not offer suitable habitats and represent range barriers. However, this does not prevent Uromastyx from travelling a few kilometres across sand from one gravel plain to another. Most species are digging, ground-dwelling animals, while some species live in rocky or mountainous areas and retreat into cracks and crevices. Some species have even been observed climbing acacia trees (U. aegyptia, U. dispar, U. ocellata and U. or- nata). Uromastyx are opportunistic herbivores, which means, that they feed mainly on plants and to a lesser extent on animals. By far the largest part of the diet is leaves, flowers, sprouts and seeds of various plant species. Spiny-tailed agamas are strictly diurnal. MATERIALS AND METHODS Morphological sampling The taxonomy presented in the present paper is based on a revision of the genus Uromastyx (WILMS 1998; WILMS & BÖHME 2000 a, 2000 b, 2000 c; WILMS & SCHMITZ 2007), in which a total of 625 specimens have been examined, including 180 specimens of Arabian species. The specimens are kept in museum collections indicated by the following abbreviations: BMNH British Museum of Natural History, London, UK (now: The Natural History Museum, London, UK, NHM) MHNG Muséum d’histoire naturelle de la Ville de Genève, Geneva, Switzerland MNHNP Muséum national d’Histoire naturelle, Paris, France MTD Staatliches Museum für Tierkunde, Dresden, Germany Review of the taxonomy of the spiny-tailed lizards of Arabia 437 Fig. 1: Distribution range of the genus Uromastyx (after WILMS 2001). MZUF Università di Firenze, Museo Zoologico “La Specola”, Florence, Italy NHMW Naturhistorisches Museum Wien, Vienna, Austria SMF Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt a.M., Germany ZFMK Zoologisches Forschungsmuseum Koenig, Bonn, Germany ZMB Museum für Naturkunde der Humboldt-Universität zu Berlin, Germany ZMH Zoologisches Institut und Zoologisches Museum der Universität Hamburg, Germany ZSM Zoologische Staatssammlung München, Munich, Germany Lists of examined specimens have been published by WILMS & BÖHME (2000 a, 2000 b, 2000 c), WILMS et al. (2002) and WILMS & SCHMITZ (2007). To obtain new information on the morphology and ecology of Uromastyx leptieni, data were collected by Thomas Wilms and Brien Holmes at a site near Abu Dhabi International Airport (United Arab Emirates) between 11 June 2005 and 16 July 2005, including morphometric and meristic data of 82 live specimens. These specimens were subsequently released in the course of a translocation project, during which a total of 213 specimens were translocated (TOURENQ 2005, C. Drew pers. comm.). 438 T.M. WILMS & W. BÖHME Plate 1: Habitat of Uromastyx thomasi at Ras Hilf, Masirah Island, Oman. Photo: T. Wilms. Plate 2: Habitat of Uromastyx aegyptia microlepis in Mahazat as-Sayd, Saudi Arabia. Photo: F. Krupp. Characters For each museum specimen the following data were routinely recorded: – snout-vent-length (SVL) – tail length – head width, measured between the anterior margins of the ear openings – head length, measured from the tip of the snout to the anterior margin of the ear opening on the left side – tail width between the 4th and 5th whorl – maximum tail width at the 5th whorl – number of scales around mid-body – number of scales between gular and inguinal fold (= ventrals) – number of gular scales (from the mental scale to a line between the anterior margins of the ear openings) Review of the taxonomy of the spiny-tailed lizards of Arabia 439 – number of scales from the mid of the lower end of the ear opening to the mental scale (left and right) – number of scales between supralabial and enlarged subocular scale – number of scales around the 5th whorl – number of tail whorls – number of scales beneath the 4th toe on the left side – number of preanofemoral pores on either side – number of enlarged scales at the anterior margin of the ear opening – number of scales from the upper to the lower end of the left ear opening (approximately three scale rows before the anterior margin of the ear opening) – number of scales from the upper end of the left ear opening to the first enlarged subocular scale – intercalary scales between the whorls (presence or absence) – presence or absence of enlarged tubercular scales at the flanks and on the dorsum With the exception of the number of scales around the mid-body, the same measurements and scale counts as in museums specimens were taken from the 82 live Uromastyx leptieni. Statistical analyses The statistical packages Excel 2000, SPSS (10.0) and R 2.2.1 (R DEVELOPMENT CORE TEAM 2005) were used to run the analyses. Two multivariate procedures were selected to evaluate data and to explore relationships within the Uromastyx aegyptia group (sensu WILMS & BÖHME 2000 a). Hierarchical cluster analysis Hierarchical cluster algorithms find successive clusters using previously established clusters and thus grouping similar objects together. Because of the many different methods to calculate dis- tances in a given matrix and the large number of clustering algorithms this method is much more subjective than the ordination techniques such as PCA (RASTEGAR-POUYANI