Liolaemus crepuscularis, Abdala, Cristian Simón & Gómez, Juan Manuel Díaz, 2006

Abdala, Cristian Simón & Gómez, Juan Manuel Díaz, 2006, A new species of the Liolaemus darwinii group (Iguania: Liolaemidae) from Catamarca Province, Argentina, Zootaxa 1317, pp. 21-33 : 22-29

Liolaemus crepuscularis sp. nov

1993, Liolaemus ornatus (part), Etheridge, R. Boll. Mus. Reg. Sci. nat. Torino. 11 (1): 137–199. 2005, Liolaemus sp. 5. Abdala, C. S. Doctoral Thesis, UNT. 277 pp.

2006, Liolaemus sp. Mina Capillitas, Abdala C. S. & Lobo F. Cuad. Herpetol. 19 (2) 3­18

Holotype. FML 16622 ( FBC 415). Adult male, from Puesto Flores, 2 km South from Mina Capillitas, Ruta Provincial 47 (km 50 a 52), 3100 m Departamento Andalgalá, provincia de Catamarca, Argentina. Collected by C. Abdala, Quinteros S., Scrocchi G. and S. Barrionuevo. March 3, 2005.

Paratypes. FML 16623 ( FBC 414; 416–418). Three males, one female, same data as holotype.

FML 16627–29 (CSA 527–528; 530). Two males, one female, from Puesto Flores, 2 km South of Mina Capillitas, Ruta Provincial 47 (km 50 a 52), 3100 m, Departamento Andalgalá, provincia de Catamarca, Argentina. Collected by C. Abdala and S. Barrionuevo. November 12, 2004.

FML 3611. One male, two females and one juvenile, form Mina Capillitas, 2800 m, Departamento Andalgalá, provincia de Catamarca, Argentina. Collected by F. Lobo, Marcus A. and R. Montero. December 18, 1995.

MCN 1937–1939 (CSA 529; 531–532). Two males, one female, from Puesto Flores, 2 km South of Mina Capillitas, Ruta Provincial 47 (km 50 a 52), 3100 m, Departamento Andalgalá, provincia de Catamarca, Argentina. Collected by C. Abdala and S. Barrionuevo. November 12, 2004.

Etymology. The specific epithet crepuscularis refers to the brown­red mixed with blue coloration of the flanks, reminiscent of the colours of nightfall. This word derives from the Latin “crepusculum” which means “twilight.”

Diagnosis. Liolaemus crepuscularis is a member of the L. boulengeri group diagnosed by a patch of enlarged scales on the posterior thigh (Etheridge, 1995). Within this group it is a member of the L. laurenti group (Abdala, 2005), diagnosed by posterior marginal teeth with straight­side tooth crowns, a dark stripe through the eye, and marked sexual dichromatism. Tooth morphology and the dark stripe through the eye distinguish this new species from the species in the L. melanops group (Abdala, 2005) ( L. boulengeri Koslowsky , L canqueli Cei & Scolaro , L. cuyanus Cei & Scolaro , L. donosobarrosi Cei , L. fitzingerii (Dumeril & Bibrón) , L. inacayali Abdala , L. josei Abdala , L. mapuche Abdala , L. martorii Abdala , L. melanops (Bursmeister) , L. morenoi Etheridge & Christie , L. loboi Abdala , L. sagei Etheridge & Christie , L. rothi Koslowsky , L. senguer Abdala , L. tehuelche Abdala , L. telsen Cei & Scolaro and L. xanthoviridis Cei & Scolaro, and sexual dichromatism distinguishes L. crepuscularis from L canqueli , L. cuyanus , L. fitzingerii , L. martorii , L. morenoi , L. sagei , and L. xanthoviridis . The lack of cephalic melanism distinguish L. crepuscularis from L. canqueli and L. melanops , and the absence of melanic gular or antehumeral collar separates it from L. canqueli , L. cuyanus , L. mapuche , L. morenoi , L. fitzingerii and L. xanthoviridis . Liolaemus crepuscularis has four scales in contact with the mental, not six as L. cuyanus and the species of the L. wiegmannii group Etheridge ( L. arambarensis Verrastro et al, L. azarai Avila, L. lutzae Mertens , L. multimaculatus (Dumeril & Bibrón) , L. occipitalis Boulenger , L. rabinoi (Cei) , L. riojanus Cei , L. salinicola Laurent , L. wiegmannii (Dumeril & Bibrón) y L. scapularis Laurent ), or variation from four to six scales as in L. josei and L. mapuche . One row of lorilabials, not two, distinguishes the new species from the species of the L. wiegmannii group.

Liolaemus crepuscularis differs from the species of the L. anomalus group ( L. anomalus Koslowsky , L. pseudoanomalus Cei , L. ditadai Cei , and L. lentus Gallardo ) (Abdala, 2005) by having caudal autotomy, tail longer than body, head longer than wider, palpebral ‘comb’ not developed, a larger number of precloacal pores in both males and females, and the absence of pterygoid teeth.

Within the L. laurenti group (Abdala, 2005), L. crepuscularis is part of the L. ornatus group (with L. albiceps Lobo & Laurent , L. calchaqui Lobo & Kretzschmar , L. irregularis Laurent , L. ornatus and L. lavillai ). These species differs from L. abaucan Etheridge , L. chacoensis Shreve , L. darwinii Bell , L. grosseorum Etheridge , L. koslowskyi Etheridge , L. laurenti Etheridge , L. olongasta Etheridge , L. quilmes Etheridge and L. uspallatensis Macola & Castro , by having a larger number of precloacal pores in females and because of being viviparous. Within the L. ornatus group, it differs from L. albiceps and L. irregularis in having a shorter maximum snout­vent length ( L. crepuscularis mean SVL 64.0 mm in comparison to 82.5 mm of L. albiceps and 86.1 mm of L. irregularis ), and females with fewer precloacal pores (= 6.5 vs. = 7.5 y = 8.4 respectively). Liolaemus crepuscularis is distinguished from L. ornatus in having males with background coloration of dorsum light brown to ferrous red and head coloration darker than the rest of the body, paravertebral markings more rounded and never in contact, dorsolateral strips less marked, body and tail with more light blue scales, little dark brown spots on the throat, belly white or light red, and lateral fields of intense ferrous red. Liolaemus crepuscularis is distinguished from L. calchaqui in having a larger body size (maximum SVL 64.0 mm vs. 57.8 mm) and different color pattern, with rounded or quadrangular paravertebrals markings well defined, light blue scales on the lateral body and tail, and lateral fields red, a pattern not present in L. calchaqui . L. crepuscularis is distinguished from L. lavillai by the dorsal coloration (brown in L. lavillai ) and the absence of light blue scales in L. lavillai .

Liolaemus crepuscularis males have a characteristic dorsal color pattern, with dorsal field light brown or ferrous red, dorsolateral stripes with yellow and light blue scales, and dark brown prescapular spot similar in size and color to the lateral markings. This set of characters of the color pattern differentiates it from the remaining species of the L. laurenti group. The presence of the prescapular spot similar to the lateral markings distinguish L. crepuscularis from species where this mark better defined ( L. abaucan , L. darwinii , L. espinozai Abdala , L. grosseorum , L. koslowskyi and L. quilmes ) and from species where it is absent ( L. albiceps , L. calchaqui , L. irregularis , L. ornatus ). In L. crepuscularis the black antehumeral arch typical of L. darwinii , L. laurenti , L. grosseorum and L. olongasta is absent.

Description of holotype. Adult male. Snout­vent length 56.7 mm. Head 1.2 times longer (12.4 mm) than wider (10.5 mm). Head height 6.7 mm. Neck 8.5 mm. Eye diameter 3.2 mm. Orbit­auditory meatus distance 4.7 mm. Auditory meatus oval shaped (height 2.7 mm, width 1.6 mm). Orbit­comisure of mouth distance 1.4 mm, distance between nares 2.4 mm. Subocular 3.6 mm. long. Axilla­groin distance 24.5 mm, tail length 96.6 mm. Body width 13.2 mm. Humerus length 8.3 mm, forearm length 6.5 mm, manus 9.3 mm. Pygal region 6.9 mm, vent width 7.4 mm. Dorsal surface of the head scales slightly rugose, with fifteen dorsal scales. Rostral wider than higher and surrounded by six scales. Mental trapezoidal in shape, larger than rostral, and surrounded by four scales. Nasal and rostral scales not in contact. Four internasals longer than wide. Six scales surrounding nasal. Canthal scale separated from nasal by two scales, one very small in contact with nasal, one larger in contact with canthal. Five scales between rostral and supercilliares, seven between rostral and frontal. Frontal divided in four. Four postrostrals. Intreparietal in contact with seven scales, and slightly smaller than adjacent right parietal, larger than left parietal. Preocular scale separated from lorilabials by one scale. Three scales on the anterior margin of the auditory meatus, superior margin with one differentiated scale, upper anterior margin with one scale projected outwards. Eight horizontal temporals and seven verticals, unkeeled. Subocular in contact with four lorilabials, not in contact with fourth supralabial. Six supraoculars. Eight supralabials, fourth equal or slightly larger than third, fifth and sixth, without scale organs. Nine lorilabials. Five infralabials, the second in contact with two scales. Four chinshields, the second separated by two scales.

Scales around midbody: 57. Dorsal scales between occiput and groin: 65, keeled, imbricated, with round posterior margin. Twenty six rows of scales on dorsum. Ventral scales imbricated, laminar, larger than dorsals. Twenty nine gulars, imbricated, unkeeled. Without gular fold. Eight precloacal pores. Antehumeral scales subtriangular, enlarged, well differentiated. Postauricular, rictal, longitudinal and antehumeral folds well marked. Longitudinal fold scales flat, unkeeled. Subdigital lamellae of fourth finger, 15. Subdigital lamellae of fourth toe, 22. Scales of the flanks with a little apical notch. Femoral patch formed by 23 conic, pointed scales. Infracarpals and infratarsals laminar, imbricated, trifid. Tricuspid teeth, with straight crowns.

Color in life. Dorsal background color of head light brown, with dark spots irregularly distributed. Head not darker than body. Black stripe transverse to orbit. Wide black spot from the posterior margin of orbit to occiput.

Dorsal background color ferrous red, two series of well marked, black paravertebral spots in form of crescent, with yellow scales in the posterior margin of spots. Light yellow vertebral field, barely evident. Black prescapular spot well defined, anterior to it, on right side of the body there is a smaller black spot, on left side these spots are united by a small longitudinal black spot. Three diffuse spots posterior to prescapular spot. Background color of flanks equal to dorsum, with light blue, yellow and white scales distributed irregularly. Limbs grey with black spots. Forelimbs with a black stripe, similar to a bracelet. Tail light gray dorsally, paravertebral spots become diffuse and fused at base of tail, flanks with numerous light blue scales.

Ventral coloration light yellow turning to light brown with dark brown marks on throat. Forelimbs, vent, and tail same color as throat. Intense yellow colored hindlimbs, especially femoral region. Two rows of small dark grey markings on tail.

Variation. Based on 41 individuals, 23 males, 17 females.

Squamation. Dorsal surface of head slightly rugose. Nasal surrounded by 6–7 scales; 6–9 supralabials; 5–8 lorilabials in one row; 6–8 supraoculars. Frontal undivided or divided in 2, 3 or 4. Parietals larger than or equal to interparietals, surrounded by 5–9 scales. Scales between rostral and occiput 13–17 scales (= 15.6). Mental scale in contact with four scales. Infralabials 4–6. Gulars 23–30 (=25.7). Temporals unkeeled; 7–11 longitudinal temporals; 7–10 transversal. Auditory meatus always higher (= 2.5 mm) than wider (= 1.6 mm), with distinctive scales on the margins, 1–3 on anterior margin and 0–2 in posterior margin. One scale projecting outwards at posterior upper margin of auditory meatus. Neck folds well developed. Head slender, longer (= 11.5 mm) than wider (= 9.7 mm), height (= 7.5 mm). Neck narrower than head and trunk. Trunk smaller (= 22.6 mm) than half SVL (= 27.3 mm). Body slender. SVL in males and females 56–64 mm (= 54.5 mm). Humerus length (= 7.8 mm), width (= 2.8 mm). Radium length (= 7.1 mm). Manus length (= 8.0 mm). Femur length (= 9.5 mm). Scales around midbody in males and females, 56–64 (= 59.7). Dorsal scales between occiput and hindlimb 59–72 (= 65.8). Dorsal scales laminar, imbricate and keeled. Subdigital lamellae of fourth finger 13–18 (= 15.1). Subdigital lamellae of fourth toe 22–25 (=23.1), with two or three keels. Infracarpals and infratarsals scales laminar, trifid, imbricated. Femoral patch with 20–27 conic, pointed scales. Ventral scales larger than dorsals. Tail 1.5–1.7 times longer than SVL. Males with 6–9 (= 7.4) precloacal pores. Females with 5–7 (= 6.5) precloacal pores.

Coloration ( Fig. 1a ). Head light brown or grey, with small dark markings on the dorsal surface. As in all the members in the L. laurentii group, both males and females have a dark transverse stripe across the orbits (Abdala, 2005). Liolaemus crepuscularis has marked sexual dicromatism, with the males having distinctive and evident coloration characters that distinguishes it from related species. The characteristic dorsal coloration of this new species is a brown to ferrous red background coloration that in some individuals may change to yellow. Flanks usually have the same color as the dorsum; some individuals have intense yellow or light brown flanks. In most specimens the markings in the form of crescent posterior to the prescapular spot are diffuse. In females the background dorsal color is grey or light brown, paravertebral markings dark grey or dark brown, in the form of a crescent, with white scales on the posterior margin. During the reproductive season, in females, the flanks and neck turn yellow. Ventrally are usually white or light yellow on the flanks, with fewer small markings on the throat than males. Belly, vent and hindlimbs are immaculate.

Distribution ( Fig. 2 ). Liolaemus crepuscularis is known only from the type locality and near localities, always above 2800 m.

Natural History. Liolaemus crepuscularis inhabits the southwestern slopes of the Nevados del Aconquija in Catamarca, always above 2800 m. This region presents an arid climate, with annual precipitation less than 300 mm, most of which is snow. The habitat is typical of the Prepuna region (Cabrera and Willink, 1980), Festuca sp., cola de zorro ( Pappophorum sp.) and muña muña ( Satureja parvifolia ) is the dominant flora. At the site there are numerous rocks, which are used by L. crepuscularis as refuge. Liolaemus crepuscularis is sympatric with L. ramirezae , and L. capillitas . Usually L. ramirezae is associated with Festuca sp, L. capillitas with larger rocks, and L. crepuscularis with the smaller ones. At this site also is found the snake Tachymenis peruviana ,. Liolaemus crepuscularis is viviparous, but nothing more is known of its biology.

Figures

FIGURE 2. Distribution of Liolaemus crepuscularis (white circles) and members of the ornatus group, plus L. espinozai. The arrow indicates the type locality.

FIGURE 1 a. Liolaemus crepuscularis (holotype, FML 16622). Male, 56.7 mm SVL.