Phymaturus videlai, Scolaro, José Alejandro & Pincheira-Donoso, Daniel, 2010

Scolaro, José Alejandro & Pincheira-Donoso, Daniel, 2010, Lizards at the end of the world: Two new species of Phymaturus of the patagonicus clade (Squamata, Liolaemidae) revealed in southern Patagonia of Argentina, Zootaxa 2393, pp. 17-32 : 23-24

Phymaturus videlai sp. nov.

( Figures 4 b, d, f)

Type material. Holotype: MLP-R.5438, adult male, collected in rocky outcrops (700 masl), near Buen Pasto town, at about 85 km northwest of Sarmiento (45°04'11"S, 69°25'25"W), Chubut Province, Argentina. Collected by J.A. Scolaro and O.F. Tappari, 15 November 2008.

Paratypes: MLP-R. 5439, adult female; MLP-R. 5440, juvenile female; JAS-DC 1149, adult male; JAS-DC 1146 adult male; JAS-DC 1150, adult female and JAS-DC 1199, juvenile female. All specimens have the same data of collection as the holotype.

Etymology. The species is named after Argentinean herpetologist Fernando Videla, who, for many years, accompanied José M. Cei in the field. They both conducted field research in several previously unexplored regions of the Argentinean Andes. As a result, he has made important contributions to the knowledge and diffusion of the herpetofauna of Argentina. We suggest the vernacular English name “Videla rockys’ lizard” and the Spanish name “Lagarto de Videla” for this species.

Diagnosis. As in many other species of the patagonicus clade, Phymaturus videlai can be distinguished from other species of this lineage by features of the colour pattern and the geographical distribution ( Figs. 1– 4 ). The coloration of this species is characterized by irregular and small blackish spots spread over the dorsal surface, whose fusion results in a peculiar pattern. This pattern exhibits moderate sexual differences that, remarkably, can also be observed among juveniles, which suggests that sexual dichromatism might not necessarily be a secondary sexual trait in this species. From most species of the patagonicus clade, except P. castillentis , P. indistictus and P. patagonicus , P. v i d e l a i is strongly isolated geographically, as shown in map of figure 3. From these three geographically related species, P. v i d e l a i can be distinguished by the coloration features described below ( Figs. 1 , 2 , 4 ), and by divergence in morphological traits detailed in the first part of the results section above. The species is a member of the patagonicus group of the genus.

Description of the holotype. A medium-sized lizard; snout-vent length (SVL) 91.4 mm; tail 100.1 mm; head length 18.5 mm; head width 16.4 mm; eye-nose distance 6.1 mm; forelimb length 33.3 mm; hindlimb length 45.7 mm; axilla-groin distance 50.3 mm (55.0% of SVL); fourth finger length 10.1 mm; fourth toe length 13.3 mm; scales in dorsal surface of the head 20; scales around midbody 206; ventral scales between mental and precloacal pores 163; scales between rostral and frontal 15; supralabial scales 9-8; infralabial scales 8-9; subdigital lamellae on fourth finger 24; subdigital lamellae on fourth toe 30; precloacal pores 10; cephalic scales granular and rounded, almost smooth; supraorbital semicircles with large bulky scales, with a small subpentagonal and rounded azygous; no distinct enlarged supraoculars; eight imbricate upper ciliar scales; subocular fragmented in 3-3 almost rectangular scales, slightly shorter than eye diameter, separated from supralabials by 2–3 irregular rows of lorilabials; preocular separated from lorilabial row by two scales; temporals smooth irregularly quadrangular, in 11–12 rows from auditive opening to the subocular; external auditory meatus enlarged, almost ellipsoidal transversally, without enlarged scales on its anterior border and with tiny granular scales on the posterior border; rostral wider than high, separated by one small scales from each nasal; nasal scale with a big central nostril, surrounded by eight small scales; nasals separated by four small irregular scales; parietals irregular and smooth with evident interparietal, surrounded by nine scales; nuchals granular in 5–6 irregular rows; post-auricular folds evident with interposed transversal folds with round, smooth and almost granular scales; mental subpentagonal of almost similar wide, but higher than rostral, surrounded by six irregular rectangular scales; two rows of 7–8 bilateral postmentals decreasing behind; dorsal scales small, round and juxtaposed; middorsal scales slightly enlarged decreasing smaller and granular toward ventro-laterals; ventrals larger than dorsals, almost pentagonals, imbricate and smooth; two gular folds with rounded, smaller scales; 75 gulars between auditory meatus; caudal scales quadrangular regularly imbricate in verticiles, on dorsum, proximally larger and smooth, centrally keeled or spined, distally more rectangular and completely keeled, but ventrally slightly keeled; scales in forelimbs round and smooth in the upper side, triangular slightly spined in the lateral region, granular and rounded in the lower side; on the hindlimbs scales are dorsally slightly spined, subtriangular, smooth and bifid towards lateral region, larger imbricate and flat in the lower side; infracarpals and infratarsals with round margins, becoming trifid at the base of the fingers and toes. Subdigital lamellae of fingers keeled; strongly curved, long claws (> 3 mm). Orange precloacal glands.

Coloration. Coloration in P. v i d e l a i is characterized by an irregular pattern of black or blackish-brown small spots spread over the dorsal surface, on a pale-brown background. The fusion of many of these spots often creates larger blackish spots with a variety of shapes. Often, these spots fuse to form black asterisks on the back of the neck and head. The patterns of fusion are also highly variable, sometimes forming series of small longitudinal stripes on the middle zone of the back, sometimes forming irregular and slightly transversal stripes, and sometimes appearing more intensely fused on the sides of the body and on the vertebral area, which creates the effect of two poorly delimited longitudinal and parallel pale-brown stripes extended from the head to the base of the tale. Sexual dichromatism is visible, although not remarkable as seen in other species of the group. Interestingly, juveniles can show signals of sexual dichromatism, as seen in adults. On the ventral surface, there is intense orange pigmentation, from the ventral neck to the tail, including hindlimbs as well. Figure 4 (b, d, f) shows colour patterns of both sexes in this species.

Morphological variation. The sample analysed comprises 4 adult males, 4 adult females, and 4 juveniles (1 male, 3 females). Because of the small sample analyzed, we only provide preliminary information on the magnitude of morphological variation observed in this species. There are slight differences in body size between the sexes, females being larger than males in SVL (mean SVL in females = 82.1 mm, range = 75.2– 94.9 mm, SD = 11.1; mean SVL males = 91.1 mm, range = 89.5–92.3, SD = 1.43). Axilla-groin distance also differs between sexes, being longer in females, as would be expected. Variation in other traits is as follows: head length = 15.2–19.1 mm, representing 20.2–21% of SVL; head width = 13.1–16.4 mm, representing 17.2–17.9% of SVL; tail length = 79.1–105.2 mm, representing 1.05–1.10 times of SVL; forelimb length = 28.1–33.9 mm, representing 35.7–36.8% of SVL; hindlimb length = 38.7–45.7 mm, representing 50.0–51.5% of SVL; axilla-groin distance in females = 43.2–55.3 mm, representing 54.8–58.3% of SVL; axilla-groin distance in males = 43.4–50.3 mm, 55.0–56.8% of SVL. Variation in meristic traits ranged as follows (means and SD in Table 1 ): scales around midbody 192–220, dorsal head scales 17–21, ventrals 152–164, precloacal pores 9–14 (restricted to males), subocular scales fragmented in 2–4 units, scales surrounding interparietal 8– 10, scales contacting mental 6, scales between rostral-interparietal 13–16 (see Table 1 for additional details on variation).

Geographic distribution. Phymaturus videlai is known from the type locality ( Fig. 3 ).

Natural history. Phymaturus videlai occurs in isolated rocky outcrops, at elevations over 700 m. The physiognomy of the geographical zone where this species is found shows highlands of basaltic origin with abundant gravel and effusive rocks strongly eroded. The dominant landscape is the barren steppe, with shrubby, low herbaceous coverage, and with high percentage of bare soil. The biotope is similar to that described above in the Natural History of P. castillensis . The dominant vegetation is composed by low shrubby, cushion bushes and sparse large clumps, but with more abundant presence of a mean cushion-grass steppe ( Stipa papposa “coirón”, Poa ligularis “coirón poa ”) ( León et al. 1998).

Even though the ecology of this species remains largely unknown, preliminary field observations revealed that, as recorded in the rest of the species of the genus Phymaturus , P. v i d e l a i is predominantly herbivorous. The reproduction of P. v i d e l a i is viviparous; we observed two captive females giving birth to two fully developed offspring each, early on February 2009. Other reptile species coexisting with Phymaturus videlai are the same mentioned above for the previous species.

Figures

FIGURE 1. Phymaturus species of the patagonicus clade, showing the remarkable diversity of patterns of coloration known within this lineage. Phymaturus agilis (a, male; b, female), P. calcogaster (c, male; d, female), P. ceii (e, male; f, female), P. excelsus (g, male; h, female), P. indistinctus (i, male; j, female), P. manuelae (k, male; l, female), and P. nevadoi (m, male; n, female). (Photos: all J. A. Scolaro, except P. nevadoi, by J. M. Cei).

FIGURE 2. Phymaturus species of the patagonicus clade (continued from figure 1). Phymaturus patagonicus (a, male; b, female), P. payuniae (c, male; d, female), P. somuncurensis (e, male; f, female), P. spectabilis (g, male; h, female), P. spurcus (i, male; j, female), P. tenebrosus (k, male; l, female), and P. zapalensis (m, male; n, female). (Photos: J. A. Scolaro).

FIGURE 3. Geographic distribution of all known members of the Phymaturus patagonicus clade. Note nonoverlapping geographical ranges of most species. Localities are indicated by numbers, and represent Phymaturus nevadoi (1), P. payuniae (2), P. zapalensis (3), P. tenebrosus (4), P. manuelae (5), P. spurcus (6), P. excelsus (7), P. spectabilis (8), P. agilis (9), P. ceii (10), P. somuncurensis (11), P. calcogaster (12), P. patagonicus (13), P. indistinctus (14), P. v i d e l a i sp. nov. (15), and P. castillensis sp. nov. (16). The wide and scattered geographical distribution shown for P. patagonicus has been considered as the result of several cryptic different species recognized until today as polymorphisms within this species, and many of them are currently under study in order to establish their status within Phymaturus.

FIGURE 4. Adult males and females of the two new species of Phymaturus of the patagonicus clade proposed in this study. Phymaturus castillensis holotype male (a) and paratype female (c) in dorsal view, and adult paratype male (e) in ventral view. All specimens from the type locality. Phymaturus videlai paratype male (b) and paratype female (d) in dorsal view, and female paratype (f) in ventral view. All from the type locality. (Photos: J. A. Scolaro, November 2008).