Acanthodactylus aureus, GUNTHER, 1903

Crochet, Pierre-André, Geniez, Philippe & Ineich, Ivan, 2003, A multivariate analysis of the fringe-toed lizards of the Acanthodactylus scutellatus group (Squamata: Lacertidae): systematic and biogeographical implications, Zoological Journal of the Linnean Society 137 (1), pp. 117-155 : 145-148

ACANTHODACTYLUS AUREUS GÜNTHER, 1903

Acanthodactylus scutellatus aureus Günther, 1903: 298 . Name-bearing type: Günther’s original description was based on ‘a considerable number of this species’. More than 30 specimens were examined from Rio de Oro (former Western Sahara) and several from Southern Algeria. The syntypes listed by Salvador (1982) are thus clearly a part of the types only: BMNH 1946.8.5.2-26, USNM 33109-33111, MNHN 1918.11- 12. The syntypes from Southern Algeria are most likely specimens of A. taghitensis , but we could not find them. It is thus important to select a lectotype which belongs to A. aureus as understood now. We select as lectotype the specimen MNHN 1918-11, an adult male from ‘Villa Cisneros’ [= Dakhla], Western Sahara. Type locality: originally Rio de Oro and Southern Algeria, restricted to ‘Villa Cisneros’ [= Dakhla], Western Sahara, by lectotype designation.

Chresonyms. Acanthodactylus inornatus aureus Günther, 1903 : Bons & Girot, 1964: 330. Acanthodactylus aureus Günther, 1903 : Salvador, 1982: 122; Arnold, 1983: 328 (part).

Distribution ( Fig. 21 ). Saharan oceanic fringe from Agadir ( Morocco) to the Cap Blanc Peninsula ( Western Sahara / Mauritania). The species is further encountered at two points in Mauritania ( Salvador, 1982) and three stations of the Senegal coast ( Böhme, 1978; Salvador, 1982). It reaches as far as 200 km inland in Western Sahara (pers. obs.). The animals from Fderik ( Mauritania) are referable to Acanthodactylus taghitensis . The Atar locality (specimen BMNH 1982.294) is wrongly positioned (far inland) in Salvador (1982) and Arnold (1983). It is in fact situated near Nouadhibou, i.e. near the coast. A. aureus is the most common lacertid on the whole oceanic side of Western Sahara.

Diagnosis. A species of variable size according to populations (reaching a maximum snout-vent length of 65 mm, mean: 53.65). Only two supralabials in contact with the subocular in 99% of the specimens, as a result of the fusion of the third and fourth (rarely the fourth and fifth) supralabials ( Table 3). Dorsal scales relatively large, not very numerous (range: 38–59, mean: 46.7; Table 2), slightly larger on the dorsum than flanks, pyramidal, and obtusely carinate (CARE code 3 or 4 in 99% of the individuals; Table 3). Fewer than two rows of supraciliary granules in 97% of the individuals ( Table 3). Generally 14 or (less often) 13 longitudinal rows of ventrals (in 77% of the specimens, range: 12–17; mean: 13.9; Table 2). Femoral pores rather numerous (range: 19–26, mean: 21.2; Table 2). Dorsal coloration distinctive, comprising dark rectangular blotches longitudinally aligned over light longitudinal lines. In old males, however, the dark blotches and the light lines can produce a mottled or even reticulate pattern. A golden yellow tone appears on the dorsum of males during reproduction. Further characterized by a concave forehead following a short but strongly acuminate snout. Supralabials sometimes uniformly greyish or purplish-blue. Easily separated from A. scutellatus , A. senegalensis , A. dumerili and A. longipes by the peculiar conformation of the supralabial scales bordering the subocular. The exceptional individuals lacking this feature can be recognized by the typical habitus of the species, resulting from its distinctive colour pattern and peculiar head profile. For distinction from A. taghitensis , see that species.

Geographical variation. None documented.

Figures

Figure 21. Geographical distribution of Acanthodactylus aureus (circles) and Acanthodactylus taghitensis (triangles). Data from Böhme (1978), Salvador (1982), Geniez & Foucart (1995), Bons & Geniez (1996), Hasi et al. (1998), Donaire et al. (2000), this study.