Phymaturus castillensis, 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 : 21-23

Phymaturus castillensis sp. nov.

( Figures 4 a, c, e)

Centrura patagonica patagonica Cei (1986: 182–183).

Type material. Holotype: MLP-R. 5441, adult male, collected in rocky outcrops (500 m asl) of Sierra del Castillo in La Juanita farm (45°08'30"S, 69°10'31"W), adjacent to Provincial Road 24, at 58 km north of Sarmiento town, Chubut Province, Argentina. Collected by J.A. Scolaro, O.F. Tappari and A. Marcus, 29 November 2008.

Paratypes: MLP-R 5442, adult male; MLP-R. 5443, adult female; MLP-R 5444 adult female; JAS-DC 1234 adult male; JAS-DC 1219 adult female. The same data as detailed for the holotype.

Etymology. The species name refers to the terra typica where this species is restricted.

Diagnosis. Phymaturus castillensis can be distinguished by a peculiar colour pattern similar to the colour patterns observed in females of some species of the patagonicus clade ( Fig. 4 a, c). However, from most species, except P. v i d e l a i, P. indistictus and P. patagonicus , P. castillensis is considerably isolated geographically by hundreds of kilometers ( Fig. 3 ). From these three geographically closer species, P. castillensis can be differentiated by its pattern of coloration ( Figs. 1 , 2 , 4 ) as well as the morphological differences detailed in the previous paragraph. In this new species there are no dichromatic differences between the sexes. The new species is a member of the patagonicus group, distinguished from the flagellifer group in having flat imbricate superciliaries rather than being rectangular and non-overlapping; slightly spiny and non-rugose caudal scales in verticilles (as seen among members of the flagellifer group). However, it has also the subocular scale not fragmented and separated from supralabials by two rows of lorilabials, as in most species of the patagonicus group, but not seen in the majority of members of the flagellifer group.

Description of the holotype. A medium-sized lizard; snout-vent length (SVL) 93.0 mm; tail 110.5 mm; head length 19.5 mm; head width 17.3 mm; eye-nose distance 7.0 mm; forelimb length measured from to the insertion of the limb into the body wall to the end of the claw of the fourth finger, 33.3 mm; hind limb length measured from to the insertion of the limb into the body wall to the end of the claw of the fourth toe, 50.8 mm; axilla-groin distance 46.5 mm (50.0 % of SVL); fourth finger length 11.2 mm; fourth toe length 17.0 mm; scales in dorsal head 19; scales around midbody 215; ventral scales between mental and precloacal pores 169; scales between rostral and frontal 14; supralabial scales 9-8; infralabial scales 9-8; subdigital lamellae on fourth finger 23; subdigital lamellae on fourth toe 28; precloacal pores 11; cephalic scales subpentagonals, smooth; supraorbital semicircles with large bulky scales, rounded, without azygous, incomplete posteriorly on both sides; no distinct rounded supraoculars; 7–8 imbricate and enlarged upper ciliaries; subocular scales rectangular, almost irregular but not fragmented, shorter than eye diameter, separated from supralabials by 2-2 irregular rows of lorilabials; preocular in contact with first lorilabial row; canthal separated from nasal by two scales; temporals smooth and rounded irregularly coniform, in 8–9 scales from auditive opening to the subocular; external auditory meatus enlarged, subellipsoidal longitudinally, with 5–6 very protruding or conically enlarged scales on its anterior border; diminute granular scales on posterior border; rostral undivided, wider than higher, separated by one row of medium scales from nasals; nasal large and surrounded by seven small scales; nasals separated by three small irregular scales; nostril rounded and large, over the centre of nasal scale; parietals irregular and rough with evident interparietal, surrounded by eight scales; nuchals strongly conical organized in 12–14 irregular rows; post-auricular folds very developed with smooth conical scales; mental subpentagonal shorter than width, but higher than rostral, in contact with six irregular rectangular scales; two rows of 5–6 bilateral postmentals decreasing behind; dorsal scales smooth, conics, small and juxtaposed; mid-dorsal scales slightly rounded and smooth, decreasingly smaller and strongly conical toward the flanks; ventro-laterals and ventrals larger than dorsals, almost pentagonal, imbricate and smooth; two gular folds with rounded, small scales; 73 gulars between auditory meatus; caudal scales quadrangular and regularly imbricate in verticiles, proximally large, conical and smooth on dorsum, or slightly keeled, distally more rectangular and strongly keeled; scales on forelimbs subtriangular and smooth in the upper side, granular, rounded and subconical in the under side; scales in hind limbs strongly conical and slightly keeled in the dorsum but larger subpentagonal, imbricate and flat in the under side; in the femoral region, small granular scales in the lower side; infracarpals and infratarsals with round margins, becoming keeled to the base of fingers and toes. Subdigital lamellae of fingers keeled; fourth toe and finger claws very developed, almost 2.5 mm of long. Eleven 11 orange-reddish precloacal glands on the scales of the cloacal region.

Coloration. Colour pattern is similar in both sexes. The general pattern is characterized by two longitudinal series of pale-brown spots on a darker brownish dorsal background. These two parallel series of clear spots are conspicuous between the parietal area of the head and the base of the tail, where disappear gradually on the dorsal tail background. On the neck and fore-back, several black scales result in a partially blackish background. Similarly intense black spots are found on the pre- and post-humeral areas. On the ventral surface, the background colour varies from brick-red to intense orange. Colour pictures of males and females are shown in figures 4a, c, e.

Morphological variation. The sample analyzed comprised 16 adult males and 14 adult females (for means and SD see Table 1 ). Analyses show slight size differences between the sexes, females being larger (in SVL) than males (mean SVL in females = 89.1 mm, range = 81.1–94.2 mm, SD = 4.0; mean SVL males = 88.0 mm, range = 78.4–93.0, SD = 2.5). Axilla-groin distance in females ranged 42.7–52.5 mm (mean = 48.6 mm, SD = 3.6, representing 50.8–55.7% of SVL); in males ranged = 42.4–49.7 mm (mean = 46.5; SD = 2.1, representing 49.6–56.4% of SVL). In both sexes, head length ranged 15.4–19.7 mm, representing 18.3–21.4% of SVL. Head width ranged 14.2–17.3 mm. Eye-nostril distance ranged 5.2–7.0 mm. Tail length ranged 99.2– 113.7 mm, representing 1.18–1.30 times of SVL. Forelimb length ranged 29.7–36.4 mm. Mean of hindlimb length in males was 49.6 mm, but in females ranged 43.6–51.9 mm (mean = 48.4 mm). Scales around midbody ranged 190–225 in both sexes combined. Dorsal head scales ranged 18–21. Ventrals ranged 152– 180. Precloacal glands observed only in males, and ranged 8–11. Subocular scales fragmented in 1–2 parts. Two rows of lorilabials between suboculars and supralabials. Scales surrounding interparietal 6–9. Scales contacting mental 4–6. Scales between rostral-interparietal 13–16. Fourth finger subdigital lamellae number 22–25. Fourth toe subdigital lamellae number 23–30.

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

Natural history. The biotope of P. castillensis is located in the arid Patagonic Phytogeographic Province, Central District, Erial subdistrict, in an ecotonal zone with the district of Subarbustive Steppe of the Argentinean Sierra ( León et al. 1998). The predominant landscape is characterized by steppes only partially covered (<50% of the surface) by small bushes and herbaceous coiron vegetation and graminea. In these Patagonian environments, the dominant bush species are Nassauvia ulicina and Chuquiraga aurea , primarily. In the Sierra del Castillo and in the areas of escorial, the predominant vegetations consists primarily of higher bushes (~ 1.70m) of the species Colliguaya integerrima , and others such as Schinus polygamus , Lycium chilense , Berberis heterophylla, Nardophhyllum obtusifolium, Chuquiraga spp ., Verbena ligustrina and scarce graminea grasses such as Stipa spp . and Poa ligularis .

Phymaturus castillensis selects rocky microhabitats in areas where other Liolaemidae ( Liolaemus elongatus , L. bibroni , L. kingii , L. fitzingeri ), Leiosauridae ( Diplolaemus bibronii , D. darwinii , Leiosaurus bellii , Pristidactylus nigroiugulus ) and Phyllodactylidae ( Homonota darwinii ) species have been recorded. However, since P. castillensis is restricted to the rocky outcrops, few individuals of these other species can be found in direct coexistence with it. In addition, the colubrid snakes Philodryas patagoniensis and Philodryas trilineata , and the viperid Bothrops ammodytoides , are common elements of the reptile fauna at the same locality, and along with the Leiosaurids, they are likely to predate on the new Phymaturus species.

Our field and lab observations reveal that P. castillensis is viviparous, as observed in all the other species of the genus. In captivity, two females gave birth to one and two fully developed offspring early on February 2009 (7th–9th), respectively. In the field, this species is often found eating plants, as also observed in most members of the genus.

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).