Liolaemus tromen, S, Abdala C., Azocar, Moreno & Paz, Bonino M. M., 2012

S, Abdala C., Azocar, Moreno & Paz, Bonino M. M., 2012, Taxonomic study and morphology based phylogeny of the patagonic clade Liolaemus melanops group (Iguania: Liolaemidae), with the description of three new taxa, Zootaxa 3163, pp. 1-32 : 7-10

publication ID	https://doi.org/ 10.5281/zenodo.246295
DOI	https://doi.org/10.5281/zenodo.6167696
persistent identifier	https://treatment.plazi.org/id/07576E4E-FFD0-FFF4-11CF-A39D8965F973
treatment provided by	Plazi
scientific name	Liolaemus tromen
status	sp. nov.

Treatment

Liolaemus tromen sp. nov.

Figs 1–4 View FIGURE 1

2007 Liolaemus hermannunezi Abdala C.S. and A. S. Quinteros, Cuad. Herp. 21 (2):119.

2009 Liolaemus hermannunezi Tulli M. J., F.B. Cruz, A. Herrel, B. Vanhooydonck , and V. Abdala, Zoology 112: 379–392.

Holotype.— FML 17735: Km 140 of provincial route 21.7 km North of Huecú, El Cholar departament, Neuquén Province, Argentina.: C. Abdala, C. Robles and R. Juárez Cols. 21/I/2006.

Paratypes.— FML 17731 – 734 and FML 17736: Same locality and date of the holotype.

FML 22386–87: near Tromen volcano, Chos Malal departament, Neuquén, Argentina. 37°04'56,8"S 70°06'15,5"W, 2189 m. Abdala, Quinteros, Scrocchii, and Stazzonelli cols. 15/ II/2007.

Diagnosis. Liolaemus tromen belongs to the L. melanops group. Within this group, the new species differenciates from L. boulengeri , L. donosobarrosi , L. goetschi , L. hermannunezi , L. inacayali , L. josei , L. loboi , L. martorii , L. melanops , L. puelche , L. rothi , L. sagei , L. senguer , L. tehuelche and L. telsen , because it shows a short antehumeral band that is not longer than the superior line of forelimbs, absent in the above-mentioned species. It also differenciates from the species belonging to the L. telsen group (except for L. rothi and L. sagei ), because L. tromen has a larger snout-vent length (SVL) of 82.5 mm versus the SVL in the species of L. telsen group (62.3 – 77.1 mm).

It is different from Liolaemus mapuche by having four scales contacting mental scale (four to six in L. mapuche ), by having a more expanded melanic ventral surface and by the absence of light blue scales on mid body and tail. It is different from L. cuyanus , because it is smaller (max SVL 82.5 mm, whereas L. cuyanus is 102 mm), four scales in contact with mental scale (six in L. cuyanus ) and by a broader ventral melanism.

The new species segregates from the Liolaemus fitzingerii group ( L. fitzingerii , L. canqueli , L. casamiquelai , L . chehuachekenk, L. fitzingerii , L. morenoi and L. xanthoviridis ), by its strong sexual dichromatism, absent in all species except for L. melanops . Moreover, it is also remarkably shorter in SVL (maximum SVL 82.5 mm in L. tromen vs. 88.4–110 mm in the other species), has a short antehumeral band, never wide or expanded and never going further than the superior line of the forelimbs. Liolaemus tromen is different from L. canqueli , L. casamiquelai , L. fitzingerii , and L. xanthoviridis because it shows evident pre and postscapular spots. Comparing it to L. melanops , L. tromen is differnt by lacking cephalic melanism, the presence of the mentioned pre and postscapular spots and males are never green in L. tromen .

Description of the Holotype. Adult male. SVL 80.2 mm. Trunk length 35.5 mm. Head longer (17.4 mm) than wide (14.0 mm). Head height 10.3 mm. Eye diameter 5.51 mm. Interorbital distance 8.4 mm. Orbit–auditory meatus distance 6.22 mm. Auditory meatus height 3.3 mm; 2.1 mm wide. Orbit–commissure of mouth distance 2.43 mm. Internares 2,74 mm. Subocular scale 4.84 mm. Femur length 15.8 mm, tibia 16.6 mm, and foot 25.1 mm. Humerus length 12.1 mm, radio length 10.5 mm, and hand 12.9 mm, base of the tail 9.19 mm, tail length 97.8 mm. Dorsal surface of the head smooth with 17 scales. Rostral wider than high, bordered by eight scales. Mental larger than rostral, trapezoidal and bordered by four scales. Nasal not in contact with rostral. Four internasals. Nasal scale surrounded by seven scales, separated from canthal scale by two scales. Four scales between frontal and supercilliaries. Eight scales between frontal and rostral. Frontal divided in four. Two postrostrals. Interparietal smaller than parietals, contacting with eight scales. Orbital semicircles complete. Five supraoculars. Preocular separated from lorilabial row by one scale. Three scales in anterior margin of auditory meatus. Twelve smooth temporals. Seven lorilabials, two of them in contact with subocular scale. Seven supralabials, none in contact with subocular. Five infralabials, second in contact, ventrally, with two scales. Six chinshields, second pair separated by two scales.

Seventy scales around midbody. Sixty-nine round, imbricate, and keeled dorsals from occiput to hind limbs. Lateral scales keeled, some keels less evident and some scales smooth. One hundred and nine, ventrals flat and imbricated scales. Thirteen scales in pigal region. Thirty-nine smooth weakly imbricate gulars. Eight precloacal pores. Antehumeral scales flat, larger in size than dorsals. Postauricular, rictal, and longitudinal folds present. Scales on the longitudinal fold granular and smooth. Fourth finger with 20 subdigital lamellae; fourth toe with 31. Infracarpals flat, imbricate, and not trifid. Infratarsals flat, imbricate, and not trifid. Teeth crown shaped, with three expanded and deep cuspids.

Color in life. Figs 1–2 View FIGURE 1 . Dorsal head light brown in Liolaemus tromen with some scales and small darker spots. Flanks in the head are lighter than dorsum and show less dark spots. Subocular scale white with dark spots.

On the trunk there is a series of eight subsquare paravertebral spots. Laterally there are two series of five lateral spots in black color and irregular shape. Dorsal background color, light brownish with yellowish, the latter is more evident on flanks of the trunk. There are no vertebral lines or dorsolateral bands. Two large and evident black scapular maculi, they are short vertical bars. The prescapular is larger than the postscapular. Antehumeral band short and wide. Fore and hindlimbs are light brownish with scarce dark spots and few dark scales. Dorsally, the tail on the proximal part is the same color as the trunk, and turns lighter at the cloaca level with more yellowish marks. The flanks of the tail are light yellow colored with very few dark spots.

Ventrally, the head is light cream without spots, but the throat, chest, belly, tail, cloaca and limbs are totally melanic. The femoral patch is light yellow. The gular melanic region extends to the neck in contact to the antehumeral band. Ventrally the tail is light yellow without spots.

Variation (based on seven specimens) Figs. 3–4 View FIGURE 3 View FIGURE 4 .

Table 2 shows variation between sexes.

Snout-vent length 61.6–82.5 mm (X = 73.9; SD = 8.5). Head length 13.2–17.4 mm (X = 15.6; SD = 1.7), width 10.9–14.0 mm (X = 12.6; SD = 1.3). Interorbit distance 6.8–9.6 mm (X= 8.4; DS= 1.0). Humerous length 9.1–12.3 (X= 11.1; DS= 1.2). Radio length 8.4–10.6 (X= 9.7; DS= 1.0). Auditory meatus height 2.1–4.2 (X= 2.9; DS= 0.6), wide 1.3–2.3 (X= 1.9; DS= 0.4). Axilla-groin distance 26.9–40.0 mm (X = 33.8; SD = 4.9). Femur length 11.5–15.8 (X= 13.7; DS= 1.5). Tibia length12.6–17.8 (X= 15.1; DS= 1.7). Tail length 77.0– 107.9 mm (X = 96.3; SD = 12.8). Midbody scales 59–70 (X =65.1; SD = 3.8). Dorsal scales, 67–75 (X = 70.1; SD = 2.7) between occiput and anterior surface of thighs. Dorsal head scales 14–18 (X = 15.8; SD =1.5). Ventrals 96–109 (X = 102.4; SD = 4.1). Scales around interparietal 6–8 (X = 7.0; SD = 0.6). Five to eight (X = 6.2; SD = 1.0) enlarged supraoculars. Ten to twelve (X =10.8; SD = 1.0), smooth temporals. Auricular, longitudinal and antehumeral fold present. Gulars 32–40 (X = 35.3; SD = 3.3). Supralabials 6–7 (X = 6.5; SD = 0.5). Infralabials 4–7 (X =5.6; SD = 1.0).

Scales around nasals 5–7 (X = 6.1; SD = 0.6). Six to eight scales between rostral and frontal (X = 7.0; SD = 0.7). Five to seven lorilabials (X = 7.0; SD = 0.9). From two to four lorilabials in contact with the subocular scale. Subdigital lamellae on fourth finger 18–22 (X = 20.3; SD =1.4); on fourth toe 25–31 (X = 26.8; SD = 2.6). Precloacal pores 7–9 in males (X= 8.0; SD=0.8), absent in females.

Noticeably, sexual dichromatism is ventral, whereas dorsally there are no differences to denote between the sexes. Head color is variable, from dark grey to dark brown, in both sexes. Some specimens show a strait dark wide line that goes from the occipital region to the eyes. This character is absent in other individuals (particularly in the Holotype, Fig. 3 View FIGURE 3 ). The dorsal background color is light brown or greyish. In males, on the medium dorso, there is a more intense yellow, also on the flanks. Remarkably, this was also observed in an adult female but lighter. Pre and postscapular bands marked and black. Antehumeral band short and generally wide. No vertebral line or dorsolateral bands. Black paravertebral spots irregularly shaped, subsquare or circular, which in females are paler with noticeable brown reddish scales in the middle of the paravertebral spots. The paravertebral spots in the middle trunk are larger, in some cases, so extended that they almost contact the lateral spots of the body. These paravertebral spots are also dark and at the midbody they tend to be Y shape. In two females, we saw white scales on the posterior margin of the paravertebral spots. Midbody flanks are spotless with a yellowish coloration. Tail coloration dorsally maintains the same color of the body, turning yellowish when it goes to the tip.

Ventrally there is an evident strong dichromatism, males show a melanic phase in the neck, chest, belly and in some individuals melanism reaches cloaca and limbs. Gular melanism in males extends to the neck, contacting to the larger prescapular spot. Background color is only visible where no melanic scales are present. Conversely, females are light colored ventrally, with some dark scales on the neck and chest. Tail is ventrally yellowish in females and yellowish to greenish in males.

Distribution. Fig. 5 View FIGURE 5 . This species is known from the type locality, 7 km N from Huecú, Department El Cholar, and the nearby Tromen Volcano, Department Chos Malal, Neuquén, Argentina. These localities are 65 km apart from each other and it is possible that several populations of the same species may be found in between these localities. There is a possibility that this species is limited to an elevation at the base of the mountains of Neuquén.

Natural History. Liolaemus tromen sp. nov was observed in an area scattered with large bushes with meteorized substrate and considerable medium to large rocks (in both localities). This species was always associated to the dominant bushes at the study sites. The type of soil is sandy, mixed with basaltic rocks. Liolaemus tromen sp nov. is sympatric to Diplolaemus sexinctus , Homonota sp., Leiosaurus belli , Liolaemus cf. elongatus , L. ceii and Phymaturus dorsimaculatus .

It is possible that like other members of the Liolaemus melanops group, Liolaemus tromen is oviparous and mainly insectivorous-omnivorous. The daily activity in adults is greater between 12:00 and 15:00 hs, when sand reaches its highest temperature. No other data on the natural history of this species is known.

Etymology. The species is named after the Tromen Volcano, Neuquén Province, Argentina. Tromen means “totora” or “cloudy or shady place” in the mapuche language.