Phymaturus yachanana, Avila, Luciano Javier, Pérez, Cristian Hernán Fulvio, Minoli, Ignacio & Morando, Mariana, 2014

Avila, Luciano Javier, Pérez, Cristian Hernán Fulvio, Minoli, Ignacio & Morando, Mariana, 2014, A new lizard of the Phymaturus genus (Squamata: Liolaemidae) from Sierra Grande, northeastern Patagonia, Argentina, Zootaxa 3793 (1), pp. 99-118 : 106-115

Phymaturus yachanana sp. nov.

( Figure 2 , 3 , 4 )

Phymaturus sp. 21 Morando, M., Avila, L.J., Perez, C.H.F., Hawkins, M. and Sites, Jr. J.W., 2013, Molecular Phylogenetics and Evolution, 66, 698 ( Fig.1 ).

Type material. Holotype: MLP.S 2636, adult male collected on rocky hills 1.74 km South of the Sierra Grande town, east of National Road 3 (41º37’S, 65º20’W, 270 m, datum = WGS 84), San Antonio department, Río Negro province, Argentina, on July 6, 2008 by C.H.F. Pérez and M. León collectors.

Paratypes: LJAMM-CNP 8203, 8205 (adult males), 8204 (adult female) collected on rocky cliffs of Sierra Grande hills, behind Sierra Grande town (41°36’S, 65°22’W, 429 m, datum = WGS 84), San Antonio department, Río Negro province, Argentina, on October 15, 2007 by C.H.F. Pérez and M. León collectors. LJAMM-CNP 14366-14367 (adult males) 14368 (adult female) collected on rocky cliffs on the west slope of Sierra Grande hills, behind Sierra Grande ghost town (41º36’S, 65º23’S, 387 m, datum = WGS 84), San Antonio department, Río Negro province, Argentina, on March 4, 2011 by C.H.F. Pérez, D. Udrizar & M. Carrera collectors.

Diagnosis. Phymaturus yachanana sp. nov. is a robust and medium sized member of the clade referred as the patagonicus group by Etheridge (1995), because it has flat imbricate superciliaries, non-rugose dorsal scales on tail, and subocular scale usually not fragmented. This new species is allopatric and differs from all other members of the clade in its unique dorsal pattern of mid-dorsal small white dots occupying only 1-8 scales and larger lateral dots or bands (3–27 scales) on a brown background.

Phymaturus yachanana sp. nov. can be distinguished from P. agilis , P . camilae, P. ceii , P. d e s ue t us, P. etheridgei , P. excelsus , P. manuelae , P. somuncurensis , P. spurcus , P. spectabilis and P. tenebrosus by color pattern features, lower scale count around midbody (see Table 1 ), reciprocal monophyly of 19 individuals on a cytochrome-b gene tree that included all related species ( Morando et al. 2013), and disjunct geographical distribution. Presence of sexual dichromatism differentiated Phymaturus yachanana sp. nov. from P. camilae , P. excelsus , P. somuncurensis , P. spurcus , P. spectabilis and P. tenebrosus . Ventral scale count in Phymaturus yachanana sp. nov. is lower than in P. ceii , and P. manuelae and shows some overlap with P. agilis , P . camilae, P. ceii , P. desuetus , P. etheridgei , P. excelsus , P. manuelae , P. somuncurensis , P. s p urc u s, and P. tenebrosus but with different average (see Table 1 ). Dorsal pattern of P. yachanana sp. nov. is composed of white smudges uniformly distributed (occupying 1–27 scales) scattered along trunk, a pattern never observed in P. ceii , P. somuncurensis , P. tenebrosus with a color pattern of more dispersed spots. Phymaturus etheridgei has a dorsal body background brown reddish with small black and white scales transversal black lines that is not present in P. yachanana sp. nov. Dorsal background brown and black with ocelli series in P. spectabilis and P. excelsus , is a pattern never observed in P. yachanana sp. nov. Dorsal pattern uniformly dark brown in P. s pu rc us with a background light brown is a pattern never observed in P. y achanana sp. nov. There is an irregular and discontinuous pattern of speckled black spots attenuated in two dorsolateral stripes in P. agilis that is not present in P. yachanana sp. nov. Creamy-yellow dorsal background, speckle with small black spots, elongated and half-moon, irregularly scattered in P. desuetus are never observed in P. yachanana . Phymaturus manuelae has black dorsal background whit irregular and discontinuous pattern of speckled light brown spots and sub elliptic spots in two paravertebral discontinuous lines, a pattern not present in P. yachanana sp. nov. Reticulated pattern in throat and gular zones observed in P. yachanana is not present in P. s p urc u s, P. tenebrosus , P. excelsus , P. ce i i, P. agilis , P. desuetus and P. etheridgei with throat and gular region gray.

Phymaturus yachanana can be distinguished from P. patagonicus and P. calcogaster for its different dorsal color pattern, differences in mitochondrial and nuclear genes, and allopatric distribution. Phymaturus yachanana has an average dorsal scale count lower than P. calcogaster (182 vs 221) but higher than P. patagonicus (182 vs 172). Ventral scale count is lower than in P. calcogaster (154 vs 174) and shape of femoral scales is different. Scales in the posterior part of the femur and tibial region are strongly mucronated in P. yachanana including a few with a slight keel, but only are slightly mucronated in P. patagonicus ( Fig. 5 ).

Description of the holotype. Adult male 90.9 mm (SVL). Axilla-groin distance 42.1 mm. Tail length (regenerated at the tip) 99.2 mm. Head length 16.6 mm; head width 16.5 mm; head depth 9.6 mm; snout length 6.5 mm (from anterior border of the orbit to tip of snout), horizontal diameter of the orbit 6.2 mm. Arm length 29.0 mm; tibial length 19.2 mm; foot length 26.0 mm. Upper head scales smooth, convex, bulged, pitted with scale organs in postrostral, internasals, frontonasals, and prefrontals. Rostral flat, two times wide as long (3.5 x 1.2 mm), divided into two equal parts. Three postrostrals, approximately equal in size and irregular in shape each other, with conspicuous scale organs (3, 1, 3); rostral and nasal without contact, separated by the anterior lorilabial scale and a small prenasal. Nasal scales almost rounded (1.5 x 1.8 mm). Nostril rounded, occupying almost all the nasal scale. Nasal scales in contact with ten-nine scales. Internasal, frontonasals, medium in size, irregular in shape; prefrontals and frontals, medium in size, hexagonal; supraorbital semicircles complete, 21–23 enlarged supraoculars; frontoparietals, parietals, and circumorbitals irregular in size and shape from each other. Interparietal pentagonal, only distinguishable by a large and conspicuous white cream “eye” in the middle, occupying more than half part of the scale. Twenty four dorsal head scales between rostral and nuchals. Two scales between nasal and first canthal. First canthal small, higher than wide. Posterior canthal larger, longer than wide. Posterior canthal slightly overlaps first supercilliary. Supercilliaries 8–10 (left-right) irregular flattened and elongated, on both sides, first four overlapped. Loreal region flat, three irregular scales on left side and two on right side. Upper ciliary scales in two rows, those of inner rows flat and quadrangular, those of outer row granular and compressed. Lower and upper ciliaries similar in size and shape. Palpebral scales small, irregular, slightly granular. One preocular, small, square; one elongate subocular (5.2 x 0.8 mm), unfragmented, one small postocular; a well marked longitudinal ridge along upper margin of subocular scale, less marked in preocular, and not marked in postocular. Three rows of lorilabials becoming only one in half subocular. Lorilabials convex, 10/10/1- 10 /7/4, approximately rectangular, slightly narrow than supralabials, pitted with conspicuous and numerous scale organs. Supralabials 9-8, flat. Temporal scales conical, smooth, swollen, juxtaposed, with a scale organ at the inferior side. Auditory meatus higher than wide (4.4 x 2.3 mm) with 4-3 outwardly projecting scales along anterior border; posterior border surrounded by granular scales. Mental pentagonal, wider than long (2.3 x 1.7); in contact with anterior infralabials, anterior sublabials and postmentals. Infralabials 8. Chinshields 9-7, irregular, first 3–5 slightly quadrangular, separated from infralabials by series of 1-2-3-4 irregular, first equal in size but becoming smaller to back. Only a scale organ present in some supralabials and infralabials. Gular scales round, flat, and juxtaposed. Sixty-five between auditory meatus. Ante-humeral and lateral fold well developed, rectal fold notorious, and postauricular folds few developed. Ante-humeral pocket well developed. Sixty-eight scales between auditory meatus and scapula. In ventral view, gular fold incomplete with its anterior margins delimited with enlarged scales on their borders.

Dorsal body scales rounded, smooth, juxtaposed. Forty-one dorsal scales along midline of the trunk in a distance equivalent to head length. Scales around midbody 185. Scales on flanks conical and sharp at the tip. There are 39 dorsal scales between occiput an anterior margin of hind-limb articulations. Ventral scales larger that dorsals, rhombals and moderately imbricated. Ventral scales between mental and precloacal pores 166. Scales of the cloacal apron equal in size than body scales, flat, rounded, moderately imbricate. Precloacal pores 9. Suprabrachial and ante-brachial scales smooth, rhombals, imbricated and mucronate, larger than dorsal body scales. Supracarpals laminar, round, smooth. Supradigital lamellae convex, imbricate. Infra-brachial scales small, granular, and ante-brachial scales smooth, rhombals with rounded posterior margins, larger that dorsal body scales. Subdigital lamellae with 3–4 keels (more conspicuous in proximal lamellae), 3–4 mucronate. Subdigital lamellae numbering I: 12; II: 16; III: 22; IV: 23; V: 17. Claws moderately long. Infracarpals with round margins and an obtuse keels, 3-mucronate. Supra-femorals smooth, imbricate, rhomboidal to rounded, and mucronate. Infrafemorals slightly larger and imbricate, smooth, rhomboidal. Supra-tarsals rhombals, smooth, mucronate. Postfemoral scales smaller and granular. Supra-tibials with a blunt keel, imbricate, becoming rounded distally, and mucronate. Infra-tibials larger than infra-femorals, smooth, imbricate. Infra-tarsals with 3 obtuse keels, mucronate. Sub-digital lamellae numbering I: 13; II: 19; III: 25; IV: 31; V: 21.

Caudal scales arranged in spinose annuli, scales larger than body and limbs scales, slightly keeled, imbricated, out-projecting.

Color in life. Dorsal coloration of body dark brown becoming lighter towards the cloacal region, speckled with mid-dorsal white smudges (1–8 scales), widening toward the lateral region of the body (3–27 scales), uniformly distributed. Dorsal coloration of head, limbs, and tail, light brown. Limbs and tail with white reticulate, transforming in rings toward the posterior half region of the tail. Throat, gular region, malar region and neck lateral region white with dark brown reticulate. Chest and upper belly yellow, transforming in mustard orange toward lower belly, cloacal apron and adjacent femoral region. Ventral region of forelimbs grey. Ventral region of tail white.

Color in preservative. After three years in preservative, the dorsal coloration of the head, dorsum, body flanks and tail maintained the original coloring, but the chest, belly and femoral regions lost the distinctive ventral yelloworange coloration, and turned white.

Variation. Based on five adult males ( Table 1–2 , Figure 6 ): SVL 72.1–90.9 mm. Axilla-groin distance 36.1–42.1 mm. Foot length 22.5–26.0 mm. Tibial length 15.7–19.2 mm. Arm length 23.6–29.0 mm. Head length 14.2–16.6 mm. Head width 14.1–16.5 mm. Head height 8.0– 9.8 mm. Midbody scales 160–193. Dorsal scales in a head length 38–44. Ventral scales 135–168. Supralabials 8–10. Infralabials 7–9. Scales around nasal 8–10. Third finger lamellae 19–22. Fourth toe lamellae 24–31. Precloacal pores 6–9. In two adult females ( Table 2 , Figure 6 ): SVL 86.1–94.5 mm. Axilla-groin distance 42.9–54.3 mm. Foot length 23.6–24.4 mm. Tibial length 16.9–18.1 mm. Arm length 25.0–28.0 mm. Head length 15.5–15.8mm. Head width 15.7–16.7 mm. Head height 8.7–9.9 mm. Midbody scales 187–194. Dorsal scales in a head length 35–39. Ventral scales 156–162. Supralabials 8–9. Infralabials 8–9. Third finger lamellae 20. Fourth toe lamellae 25–28. We found six lizards with four scales contacted to the mental shield and one with six.

Coloration in females differs from the males. In the female LJAMM-CNP 14368, dorsal background of body is black with four series of blotches from neck to posterior region of the scapula and three series from lumbar to pelvic region, both series, white and brown center, the rest of the dorsal surface is uniformly covered with smaller blotches of different sizes, usually white colored or white with a brown center. The blotches are transformed onto a dark reticulate towards the sides of the body, forelegs and anterior region of the tail. The hind limbs and most of the tail have light brown background with a white blotch. The coloration of the head is light brown. The ventral surface gray, gular region, throat, chest with a dark brown reticulate that fades towards the upper belly and body lateral region to the insertion member; belly center light brown, and cloacal apron and femoral region adjacent gray. Ventral tail light brown with white smudges, that towards the tip turns into rings that occupy a single scale line. The other female of the type series has the same color pattern but more blurred.

Four males have the same basic color pattern with greater or lesser degree of development of the dorsal white smudges. In the LJAMM-CNP 8205 specimen, smudges in the dorsolateral region are small bands, and in neck and scapula, three series of ocelli slightly distinguishable. The male LJAMM-CNP 14367 has a dorsal color pattern similar to females but with mustard orange color in the lower belly, cloacal and femoral adjacent region.

Etymology. The specific name, “ yachanana ”, means " with abundant iron ore " in the language of the northern Tehuelches, a native group that inhabited the region of the type locality (yacha =means iron ore, nana= abundant). This name was used for a locality near Sierra Grande hills by the Swiss naturalist and explorer Jorge Claraz during his travels to the region in the summer of 1865–1866 ( Casamiquela 1998, see p. 162). Sierra Grande hills harbor the only one iron mine of Argentina.

Geographic distribution. Phymaturus yachanana sp. nov. was collected in rocks above 270 m above sea level in the Sierra Grande region. Sierra Grande is an assemblage of small hills with a complex origin, but in the early to mid Jurassic, the region had an intense volcanic activity that gave origin to the actual rocky landscape named Marifil Volcanic Complex; later the area was occupied by marine ingressions and associated deposits formed the sedimentary landscape ( Zanettini 2008; Márquez et al. 2011). The continental climate is arid with an average annual temperature of 14 ° C and extremes of -20º C and 42º C, rainfall is between 50 and 200 mm annually with prevailing westerly winds (Busteros et al. 1998). Sierra Grande Mountains is the main and more conspicuous geographic feature in the area with about 439 m of elevation.

Natural history. Phymaturus yachanana sp. nov. is a very scarce and difficult to find species. Since the type locality is very close to a populated area, the environment has been disturbed by human activities, including cattle grazing, stone removal, quarries, or earth movements. A few years ago, the mining activities were interrupted for almost a decade but very recently the mine was reopened and new disturbances were made in the area. We hope that the description of this new species will encourage fauna authorities to implement some conservation program in this region. Little information about natural history and biology of this new species is available. Phymaturus y achanana sp. nov. was observed basking in rocky outcrops above 270 m ( Figure 7 ), usually surrounded by vegetation characteristic of the Monte Patagónico Phytogeographic District of the Monte Phytogeographic Province, characterized by Larrea spp . shrubs communities ( Roig 1998), also species of Haploppapus pectinatus , Mulinum spinosum , Nassauvia glomerulosa , Senecio megaoreinus , Adesmia patagonica , Tetraglochin alatum , Valeriana carnosa and several species of grasses ( Stipa spp .) were registered in the area. The holotype and paratypes were found by active search, basking on rocky outcrops and hiding in crevices. Phymaturus yachanana sp. nov., adopt in summer a bimodal activity pattern as environmental temperatures reach 42 ºC (Busteros et al. 1998), and in early and late activity seasons shifts to unimodal. Two individuals of the snake Philodryas trilineata were spotted in the type locality, and P. patagoniensis and Phalotris bilineatus have been cited. Homonota darwinii was the only lizard observed sharing the same microhabitat. No studies about reproduction, diet or other natural history characteristics are available, but as in other related species of Phymaturus , P. yachanana sp. nov. is probably viviparous and feeds on plant matter, and possibly some arthropods. Phymaturus yachanana sp. nov. is the only Phymaturus found completely inhabiting a region with vegetation typical of the biogeographic province of Monte. Some populations of other members of the Phymaturus patagonicus group are found in ecotonal environments between Patagonian Steppe and Monte but never completely surrounded by Monte. All other populations of Phymaturus observed between Paileman, Colorada and Chata Hills, are surrounded by typical Monte vegetation and probably could be assigned to the new species. More conclusive evidence and studies on species limits must be done to correctly identify them.

Remarks. Phymaturus yachanana sp. nov. belongs to the calcogaster species group according to a recent molecular phylogenetic study by Morando et al. (2013). Although this clade is moderately supported with the BEST species tree approach ( Fig. 6 in Morando et al. 2013), this is a method specifically designed to recover species trees (as opposed to concatenated gene trees obtained by other methods). Thus, we take this result as our best working hypothesis, including Phymaturus yachanana sp. nov. ( Phymaturus sp. 21 in Morando et al. 2013) as a member of the calcogaster group, which also includes P. calcogaster and P. patagonicus and several populations/ species awaiting detailed studies to correctly allocate them to specific level. These lineages are distributed along the eastern and southeastern rim of Somuncurá Plateau, on small and flat hills and rocky cliffs along small canyons, in Río Negro and Chubut provinces (Central Patagonia). This region includes a poorly studied set of lizard populations of Phymaturus , with extensive morphological polymorphism and their identity is still matter of study. Based on cyt-b data ( Morando et al., 2013), uncorrected genetic distances between previously morphologically described species of Phymaturus are as low as 0.81% ( P. nevadoi vs. P. payuniae ), 1.24% ( P. somuncurensis vs. P. ceii ), 1.8% ( P. manuelae vs. P. spectabilis ) for some species pairs within the patagonicus group. For species pairs within the palluma group, the smallest distances are 1.10% ( P. verdugo vs. P. roigorum , and P. vociferator vs. P. flagelliger ), 1.36% ( P. antofagastensis vs. P. mallimaccii ). Although some species pairs have even smaller values, they may be conspecific (Morando et al., op. cit). The smallest uncorrected genetic distance between the new species described here and others geographically and phylogenetically closely related of the patagonicus group are: P. yachanana vs P. calcogaster = 2.2%, P. yachanana vs P. patagonicus = 7.4%, P. yachanana vs P. tenebrosus = 2.86%, which are above the average threshold for closely related species of this genus.

Figures

FIGURE 1. Principal component analysis with residuals of continuous variables using SVL as regressor. Also shown confidence 95 % ellipses around the species’ individuals. References: B—black: Phymaturus yachanana sp nov., L—red: P. patagonicus, M—green: P. calcogaster.

FIGURE 2. Phymaturus yachanana sp. nov., dorsal and ventral view of the holotype (MLP. S 2636), from Sierra Grande Hills, San Antonio Department, Río Negro Province, Argentina.

FIGURE 3. Dorsal and ventral view of a paratype female of Phymaturus y achanana sp. nov.

FIGURE 4. Phymaturus yachanana sp. nov., dorsal and ventral view of the holotype (MLP. S 2636), in preservative.

FIGURE 5. Posterior suprafemoral scales of: (A) Phymaturus yachanana sp. nov. (MLP. S 2636) strongly mucronate; (C) P. patagonicus (LJAMM-CNP 3205) few and moderately mucronate. Supratibial and pretibial scales of: (B) Phymaturus yachanana sp. nov. (MLP. S 2636) keeled and strongly mucronate; (D) P. patagonicus (LJAMM-CNP 3205) few and moderately mucronate.

FIGURE 6. Dorsal and ventral color variation in the type series of Phymaturus y achanana sp. nov.

FIGURE 7. Type locality of Phymaturus y achanana sp. nov. Upper: general view of the area. Below: close view of the common outcrops where lizards were collected, observed basking or hiding in crevices.