Acanthodactylus zagrosicus, Mozaffari & Mohammadi & Saberi-Pirooz & Ahmadzadeh, 2021

Mozaffari, Omid, Mohammadi, Sima, Saberi-Pirooz, Reihaneh & Ahmadzadeh, Faraham, 2021, A new species of Acanthodactylus Fitzinger, 1834 (Sauria: Lacertidae) from the Zagros Mountains, Iran, Zootaxa 5047 (1), pp. 17-32 : 24-28

Acanthodactylus zagrosicus sp. nov.

( Figs. 3 & 4 ; Table 2)

Acanthodactylus boskianus Rastegar-Pouyani 1999 ; Heidari et al. 2014; Šmid et al. 2014; Mozaffari et al. 2016

Holotype. ZFMK103173 . Adult male. Collected from the roadside from Gotvand to Saland (around 60 km east of Dezful city, Khuzestan Province, Iran), 32° 26´51.54˝ N, 48° 52´26.64˝ E at an elevation of 460 m a.s.l. on April 2005 by Omid Mozaffari.

Paratype. ZFMK103174 . Adult female. Collection details as the holotype .

Diagnosis. A medium to large size Acanthodactylus species with: 1) three rows of scales around 4 th toe; 2) ventral plates in 10 longitudinal rows across belly; 3) four supraoculars, the last one is sometimes divided; 4) smooth temporal and supratemporal scales; 5) strong keel on dorsal and upper caudal scales; 6) a single large and sharply keeled subocular scale; 7) subocular scale in contact with mouth or supralabials; 8) large ear opening with anterior denticulation; 9) 43–50 mid-dorsum scales; 10) 25–30 transverse scales in ventral.

Comparisons. Acanthodactylus zagrosicus sp. nov. can be differentiated from most species of the Western and scutellatus clades of Acanthodactylus due to their North African distribution. It can be distinguished from species of the Eastern clade and from those geographically close to or from Iran, as follows: from species of blanfordii group ( A. blanfordii and A. schmidti ), cantoris group ( A. arabicus Boulenger, 1918 , A. cantoris , A. gongrorhynchatus Leviton & Anderson, 1967 , A. haasi Leviton & Anderson, 1967 and A. tilburyi Arnold, 1986 ) and A. hardyi by having three rows of scales on fingers (vs. four), smooth temporal scales (instead of keeled temporal scales) and 10 straight longitudinal rows of ventral scales (vs. 12 or more). It is further distinguished from A. gongrorhynchatus by having large ear opening (instead of almost closed off by two or three scales on the anterior portion). It can be differentiated from A. grandis by having strongly keeled dorsal scales (instead of smooth or weakly keeled), 10 straight longitudinal rows of ventral scales (vs. 14–16) and three rows of scales on fingers (instead of four). Acanthodactylus zagrosicus sp. nov. can be excluded from species of the tristrami group ( A. tristrami (Günther, 1864) and A. robustus Werner, 1929 ) by having strongly keeled upper caudal and dorsal scales (instead of smooth scales on upper caudal and dorsal), having four supraocular scales (vs. two or three) and anterior denticulation in ear opening that is not present in the tristrami group’s species. This new species can be excluded from members of micropholis group ( A. micropholis and A. khamirensis ) by having less mid-dorsum scales (43–50 vs. 50–63 in A. micropholis and 56–64 in A. khamirensis ) and having four supraocular scales (vs. two or three). In addition, it also can be distinguished from A. micropholis by having strongly keeled dorsal scales (instead of smooth or feebly keeled), and from A. khamirensis by having less rows or transverse scales in ventral (25–30 vs. 32–39). Among the members of the opheodurus group, it can be differentiated from A. felicis Arnold, 1980 by having less transverse ventral scales (25–30 vs. 36–42), more straight longitudinal rows of ventral scales (10 vs. 8), smooth supratemporal scales (instead of keeled supratemporals), and it can be distinguished from A. opheodurus Arnold, 1980 by having smooth temporal scales (instead of sharply keeled temporal scales), smooth supratemporal scales (instead of very conspicuous longitudinal central keel on supratemporal), and by having less transverse ventral scales (25–30 vs. 29–36).

Regarding to its morphological characters, Acanthodactylus zagrosicus sp. nov. is similar to members of the boskianus group along with A. boskianus , A. nilsoni , and A. schreiberi . This species can be distinguished from other species of this group by smooth temporal scales and lacking longitudinal central keel on supratemporals (instead of sharply keeled temporal scales). Moreover, Acanthodactylus zagrosicus sp. nov. can be differentiated from A. nilsoni by having strongly keeled dorsal scales (instead of weakly keeled dorsal scales), less collar scales (8–9 vs. 10–12), and more longitudinal rows of ventral scales (10 vs. 8). It can be distinguished from A. schreiberi by having strongly keeled dorsal scales (instead of smooth dorsal scales) and less gular scales (25–30 vs. 31–36).

Description of Holotype. A medium to large-sized Acanthodactylus with a SVL of 75 mm and TL of 174 mm; head elongated and snout pointed; body moderately slender; Scalation ( Figs. 3 & 4 ): Rostral shield is not prominent, followed by paired supranasals, their suture very short. Frontonasal hexagonal and flat, with the length of about half of frontal; prefrontals almost hexagonal and convex, the length of the suture is almost half the length of their width; frontal elongated and deeply concave anteriorly, broader anteriorly than posteriorly; Frontoparietals suture is almost half the length of the frontal, and almost the same length at their posterior margins with the parietals. Parietals are square shaped, their length equals to their width. Interparietal is relatively large, diamond shaped, with a clear parietal foramen; its length larger than its width. Occipital scale is absent. Four supraocular scales, the two middle ones larger than the first and forth, the forth supraocular sometimes divided; the first three supraoculars in contact with frontal; six superciliary scales on each side, the first is the longest; Nostril in dorsolateral position and in contact with the supranasal, postnasal and first supralabial scale; the nasal scale developed; two loreal scales, the anterior one smaller, the posterior longer and in contact with the anterior first supraciliaries and subocular; Two suboculars, the anterior longer than posterior, keeled and wedged between the fourth and fifth upper labials, not contacting the lip; Scales in center of lower eyelid small and round. Seven supralabials, four anterior to subocular, the fourth upper labial is the longest, followed by the fifth; Two supratemporals, the anterior longer than the posterior; Temporals mostly hexagonal, small, pointed and granular, progressively larger and smoother towards the upper labials; a single smooth elongated supratemporal rests on seven temporals and in contact with a small quadrilateral smooth scale posteriorly; A small tympanic scale is present. Anterior margin of the ear opening with four moderate denticulation. Six lower labials; five pairs of submaxillary shields, first three pairs in contact along the center; 28 rounded gular scales between submaxillary shields and collar, gular fold absent.; collar rounded and made up of eight scales.

Dorsal and upper caudal scales distinctly keeled; dorsal scales are small and pointed at the nape, slightly larger and keeled at mid body between the limbs, becoming larger and flat with a keel on the tail; 50 moderate scales across mid-dorsum; Scales on lateral body are small, almost granular, pointed or slightly keeled, becoming larger and flat ventrally. 10 longitudinal and 28 transverse rows of ventral plates; two rows of 23 femoral pores that reach the knee, separated by a single scale; Three enlarged preanal plates in a longitudinal row between the anterior cloacal margin and the gap between the two series of femoral pores.

Dorsal surfaces of the limbs covered by medium sized, imbricate scales; anterior surface of the limbs covered by larger, unkeeled, imbricate scales; posterior covered with smaller granular scales. The ventral side of the forelimbs is covered with small, smooth scales; ventral surface of hind limbs covered with large flat scales. Three longitudinal rows of scales on the toes, fourth toes with 21 subdigital lamella and moderate lateral fringes; 24 scales in the fifth caudal annulus.

Description of Paratype. Variation in measurements and scalation of the paratype is presented in Table 2. The paratype agrees in general with the holotype. Size: SVL of 69 mm and TL of 165 mm. Scalation: seven supralabials, four anterior to subocular; five submaxillary shields, first three pairs in contact for half of their length; Subocular keeled and in contact with the mouth ( Fig. 3E ); four supraocular scales, the two middle ones larger than the first and the forth one sometimes divided; six superciliary scales; only one row of granules between the supraoculars and superciliaries; ear opening large and with four moderate denticulation anteriorly; temporals mostly hexagonal, smooth and without keels; a single smooth elongated supratemporal in contact with a small quadrilateral smooth scale posteriorly; 30 gular scales between submaxillary shields and collar; collar made up of eight scales; dorsal and upper caudal scales distinctly keeled; 47 small to medium scales across mid-dorsum; 10 longitudinal and 30 transverse rows of ventral plates; two rows of 23/26 femoral pores separated by a single scale that reach the knee; fourth toes with 21 subdigital lamella and moderate lateral fringes; 24 scales in the fifth caudal annulus.

Coloration. In life, dorsal side of head and body is sandy light brown to light orange with a series of darker brown spots. Four longitudinal medial light cream or milky white stripes extend from back of the head; the two external stripes starting from the upper margin of ear opening, and contact in the pelvic region, extending to dorsal tail; the two medial stripes merge into one medial stripe after the fore limbs. Along the longitudinal medial stripes are numerous irregular dark brown to black spots, mainly on the dorsal body, and slightly extending to the tail. These spots fade with age. The tail is sandy light brown with light creamy dorsal medial stripe. Venter is milky white. We did not collect juvenile forms, but our on-site observation detect that their ventral side of the tail is light pinkishred, while it is milky white in adults. In preserved specimens the coloration become pale and the light longitudinal stripes turn light gray.

Etymology. Acanthodactylus is a combination of two Greek word; “akanthodis” meaning thorny and “dachtylo” meaning finger. The words together refer to lateral fringes on hindlimb fingers. The epithet zagrosicus refers to the Zagros Mountains in western Iran, the known habitat of this species. So Zagrosian Fringe-fingered lizard is the recommended English name for this new species.

Distribution. Acanthodactylus zagrosicus sp. nov. is distributed widely in the Zagros Mountains including Kermanshah, Lorestan, Ilam and Khuzestan Provinces of Iran. They may be found in other parts of the Zagros Mountains with the same habitat; but there is no evidence yet.

Habitat and natural history notes. Acanthodactylus zagrosicus sp. nov. inhabit sandy-silty soils to gypsum and limestone deposits. The species avoids sandy habitats and prefers foothills with loose gravely soils with scattered bushes specially Astragalus sp. , Atraphaxis sp. , Pteropyrum sp. and other Xerophyte plants. The species can be found at elevations of 450–1600 m.

Figures

FIGURE 3. Morphology of Acanthodactylus zagrosicus sp. nov. (Holotype ZFMK103173(♂) and paratype ZFMK103174(♀)). (A) Holotype, dorsal view of head; (B) Holotype, ventral view of head; (C) Holotype, temporal region and supratemporal scales, right side; (D) Holotype, lateral view of head, right side; (E) Paratype, lateral view of head, right side; (F) Ventral view of hind limb and fourth toe; (G) Holotype, dorsal scales; (H) Holotype, caudal scales in fifth annulus; (I) Holotype, ventral view of hind limbs and femoral pores; (J) Paratype, Dorsal view and coloration.

FIGURE 4. Head scalation of Acanthodactylus zagrosicus sp. nov. (A) Lateral view; (B) Dorsal view.