Phymaturus williamsi, Lobo, Fernando, Laspiur, Alejandro & Acosta, Juan Carlos, 2013

Lobo, Fernando, Laspiur, Alejandro & Acosta, Juan Carlos, 2013, Description of new andean species of the genus Phymaturus (Iguania: Liolaemidae) from Northwestern Argentina, Zootaxa 3683 (2), pp. 117-132 : 122-124

Phymaturus williamsi sp. nov.

Holotype: MCN 2820. Male. Quebrada vallecito, 40 km W of Calingasta town, Calingasta department, San Juan province. 31º11’21’’ S; 69º42’15.1’’ W, 3000 m asl. A. Laspiur, R. Acosta & J. C. Acosta cols. 11/05/2008.

Paratypes:.MCN 2808-10, 2812-14, 2815, 2816-17, 2821. Same data as holotype. MCN 3259-65. Quebrada Vallecito, 40 km W of Calingasta town, Calingasta department, San Juan province. 31º11’21’’S; 69º42’15.1’’W, 3000m asl. A. Laspiur & J. C. Acosta cols.

Diagnosis. Phymaturus williamsi belongs to the palluma group because it shares their well-known apomorphies with all the other members: square, non-imbricate superciliaries, rugose dorsal scales of the tail, usually a fragmented subocular, and subocular and supralabials separated by two or more scale rows. This new taxon belongs to the Puna subclade of the palluma group ( Lobo & Quinteros 2005b) because it shows the typical dorsal “spray” pattern (southern palluma group members show a dorsal reticulated pattern). Within the Puna subclade, P. williamsi differs from all other species in its particular character combination; P. williamsi shows the dorsum of neck homogeneous melanic, not interrupted in the midline as in P. antofagastensis , P. laurenti and P. punae . Phymaturus williamsi lacks enlarged scales posterior to the cloacal opening which are present in P. laurenti and P. aguanegra . Tarsal scales are strongly keeled in P. williamsi but slightly keeled in P. laurenti . Phymaturus williamsi exhibits an “aggregate” dorsal pattern, unlike the homogeneous spray of most Puna species; a similar condition is only found in P. antofagastensis (Fig. 12D in Lobo & Quinteros 2005b). Phymaturus williamsi lacks enlarged scales on the anterior margin of the antehumeral fold and in the centre of chest, as in P. antofagastensis and P. laurenti . Flank coloration in females is absent in P. williamsi but is present in P. antofagastensis (yellow), P. laurenti and P. mallimaccii (orange). A light-gray vertebral stripe, which is absent in P. antofagastensis and P. laurenti , is present in P. williamsi ; a dark gray vertebral stripe can be present in individuals of P. aguanegra . Females of P. williamsi lack white transversal stripes on the dorsal pattern, as in females of P. antofagastensis and P. laurenti (not all individuals). Phymaturus williamsi exhibits a tricolor dorsal pattern, with two types of brown and a scattered ferriferous oxide spotting; this pattern is not found in any other species of the group, with the exception of P. aguanegra and P. paihuanense . A scapular spot is mostly absent (only one subadult male with a vanishing spot) in P. williamsi as in most of Puna species, with the exception of P. mallimaccii . Preocular scale is in contact with canthal scale in P. williamsi , whereas it is separated by a smaller scale in P. antofagastensis , P. aguanegra , P. laurenti , and P. punae . Rostral scale can be divided in P. williamsi but is always undivided in P. aguanegra , P. laurenti , and P. mallimaccii . P. williamsi shows the largest number of scales counted around midbody within the Puna subclade (x= 213.4; 186–235); the remaining species show a mean below 200 scales. Neither males nor females of P. paihuanense exhibit head melanism (present in P. williamsi ); males of this species show enlarged scales on the anterior margin of the antehumeral fold (absent in P. williamsi ). Phymaturus williamsi differ of P. damasense in the presence of non-projected scales in the anterior border of auditory meatus (present in P. damasense ) and color pattern of males and females.

Description of holotype. Male. SVL 103.0 mm. Head length 18.4 mm. Head width 18.2 mm. Head height (at parietal) 10.4 mm. Axilla-groin 51.4 mm (49.8 % of SVL). Tail length (complete, not regenerated) 97.7 mm (0.95 times SVL). Body moderately wide, trunk width: 40.0 mm (38.9 % of SVL). Twenty-four smooth dorsal head scales. Four, three (three times), two (two times) organs in postrostrals. Nasal bordered by nine scales, not in contact with rostral. Canthal separated from nasal by two scales. Loreal region flat. Eleven enlarged supralabial scales, none in contact with subocular. Eleven enlarged infralabials. Auditory meatus oval with three-four small conical projecting scales on the anterior margin. Auricular scale absent. Ten convex, juxtaposed temporals. Rostral undivided. Mental subpentagonal, in contact with seven scales. Interparietal bordered by 10 scales. Frontal region without an azygous scale. Supraorbital semicircles inconspicuous. No distinctly enlarged supraoculars. Twelve imbricate flat superciliaries. Subocular fragmented in three scales, separated from supralabials by one to two rows of lorilabials. Thirteen to 15 lorilabials, 12 contacting subocular on the right side. Preocular scale separated from lorilabial row by three scales. Scales of throat round, flat, and juxtaposed. One hundred and three gular scales between auditory meata. Lateral nuchal folds well developed, with granular scales over longitudinal fold. Antehumeral pocket well developed. Seventy-five scales between auditory meatus and shoulder. In ventral view, gular fold not well developed and posterior gular folds present with their anterior margins without enlarged scales on their borders. Enlarged scales in the centre of chest absent. Dorsal scales round, smooth, juxtaposed. Forty dorsal scales along midline of the trunk in a distance equivalent to head length. Scales around midbody: 220. Middorsal scales not enlarged compared to those on flanks. Ventral scales larger than dorsals. Ventral scales between mental and precloacal pores: 199. Eight precloacal pores in an undivided row with two supernumerary pores. Brachial and antebrachial scales smooth with rounded posterior margins. Supracarpals laminar, round, smooth. Subdigital lamellae of fingers with three keels. Number of subdigital lamellae of fingers I: 11; II: 13; III: 22; IV: 23; V: 15. Claws moderately long. Supradigital lamellae convex, imbricate. Infracarpals and infratarsals with round margins and 2–3 keels. Supracarpals and supratarsals smooth, with round posterior margins. Subdigital lamellae of toes I: 11; II: 17; III: 22; IV: 27; V: 20.

Pattern of body and limbs ( Figs. 4 and 5 ): This species exhibits an aggregate pattern of brown spots similar to that of P. antofagastensis (Fig. 12D in Lobo & Quinteros 2005b). Dorsum of neck and head is more melanic than in P. aguanegra individuals. In this species a vertebral line is usually conspicuous, dividing the dark coloration of neck ( Fig. 5 ).

Coloration in life ( Fig. 5 ): The general coloration varies between brown-orange to light yellow; as in P. aguanegra , this dorsal coloration exhibits the characteristic ferric oxide shade.

Variation: Based on 20 adult specimens (10 males and 10 females). SVL 95.4–104.5 mm (x = 100.2; SD = 3.1) for adult specimens only. Head length 16.3–18.4% (x = 17.4%; SD = 0.1) of SVL. Tail length 0.86–1.05 (x = 0.92; SD = 0.06) times SVL. Scales around midbody 186–235 (x = 213.4; SD = 13.0). Dorsal head scales 22–27 (x = 24.0; SD = 1.4). Ventrals 169–209 (x = 191.1; SD = 11.4). Scales surrounding interparietal 8–10 (x = 8.8; SD = 0.9). Scales of neck along longitudinal fold from posterior border of auditory meatus to shoulder 64–89 (x = 76.1; SD = 7.4). Gulars 82–110 (x = 95.2; SD = 7.7). Scales between rostral and frontal 9–14 (x = 10.6; SD = 1.6).

Etymology. We name this new species in honour of our Argentine colleague and friend Jorge Williams, in recognition of his effort and dedication for the development of herpetology in our country.

Distribution. Only known from its type locality.

Figures

FIGURE 5. Patterns of coloration in life of Phymaturus williamsi sp. nov. A and B: Males; C and D: Females.

FIGURE 4. A. Dorsal view of the holotype specimen of Phymaturus williamsi (MCN 2820); B. Ventral view of the same specimen. SVL: 103 mm.