*Liolaemus nazca*

2017. *Liolaemus* "Nazca" Aguilar et al.

Holotype. MUSM 31523: adult male collected in Marcona District, Nazca Province, Department of Ica, Peru, 15.120 S, 75.338 W, 466 m, on 17 January 2013 by César Aguilar, César Ramírez and Alejandro Mendoza.

Paratypes. MUSM 16100, 31520, 31526, 31541: four adult males, same data as holotype. MUSM 31,521, 31,525, 16,101: three adult females, same data as holotype. MUSM 31524, 31527, 31522: three juveniles, same data as holotype.

Referred specimens. BYU 50471–50472: two males, same data as holotype. BYU 50506–50508, BYU 50510: four females, same data as holotype.

Diagnosis. *Liolaemus nazca* belongs to the *L. montanus* group because it lacks a patch of enlarged scales on the posterior thighs. *Liolaemus nazca* forms a clade with other Pacific coast species, *L. insolitus*, *L. poconchilensis* and *L. chiribaya* sp. nov. It differs from *L. poconchilensis* in being larger (with a maximum SVL of 59.8 mm; 55.9 mm in *L. poconchilensis*) and lacking enlarged serrate ciliary scales. *L. nazca* differs from *L. insolitus* and *L. chiribaya* sp. nov. by having slightly keeled dorsal scales on the body, which become more conspicuous towards the vertebral line. *Liolaemus nazca* also differs from *L. poconchilensis* and *L. chiribaya* sp. nov. by lacking a "phrynosauroid" or "toad-like" head. *Liolaemus nazca* presents an intense orange or yellow ventral region with dark spots, in contrast to *L. insolitus* and *L. poconchilensis,* both of which have clearer ventral regions, and *L. chiribaya* sp. nov. which has two orange lateral stripes on venter.

*Liolaemus nazca* is distinguished from other Peruvian species of the *L. montanus* group by its bright green and turquoise scales on body flanks surrounded by yellow and black scales. *Liolaemus nazca* also differs from *L. aymararum*, *L. evaristoi*, *L. melanogaster*, *L. polystictus*, *L. robustus*, *L. thomasi* and *L. williamsi*

in having a smaller SVL (65.9 mm versus 70.1–103.0 mm). *Liolaemus nazca* has fewer scales around midbody (53–62) than *L. signifer* (67–110), and the number of vertebral scales (between the occiput and anterior level of hind limbs) in *L. nazca* is smaller (53–57 scales) than *L. evaristoi* and *L. signifer* (60–129 scales), and greater than those of *L. aymararum*, *L. ortizii* and *L. thomasi* (30–53). *Liolaemus nazca* di ffers from *L. etheridgei*, *L. ortizii* and *L. thomasi*, all of which have noticeably keeled scales. *Liolaemus nazca* females di ffers from *L. melanogaster*, *L. polystictus* and *L. thomasi* females by having vestigial precloacal pores. *Liolaemus nazca* males have fewer precloacal pores (3–6) than males of *L. annectens* (6–7) and *L. etheridgei* (6–9).

Description of the holotype. Adult male, SVL 64.5 mm, head length 16.3 mm, head width 13.2 mm, head height 9.5 mm, groin armpit distance 26.4 mm (39.8% SVL), foot length 16.3 mm (25.3% SVL), tail length 77.6 mm (120.3% SVL). 20 dorsal head scales (between the anterior edge of the auditory meatus to the anterior edge of the rostral); dorsal head scales smooth, occipitoparietal scales irregular and convex, frontonasal and parietal area with convex scales; scale organs more abundant in the prefrontal, internasal, lorilabial and loreal regions; supralabial region without scales organs; three organs in the left and one in the right post-rostral. Nasal scale separated from rostral, and separated from the first supralabial by one scale, right nasal bordered by eight scales; cantal separated from nasal by two scales. Six supralabials. Ten lorilabial scales, four in contact with subocular. Six infralabials. Oval auditory meatus (height 2.4 mm, width 1.0 mm) with two small scales on anterior margin. Seven smooth and convex temporal scales. Distance between orbit and auditory meatus 6.5 mm. Rostral almost three times as wide as tall (width 2.8 mm; height 1.1 mm). Mental subpentagonal, almost twice as wide as tall (width 2.7 mm; height 1.5 mm). Hourglass-shaped interparietal, with elongated posterior apex, bordered by eight scales, parietals of similar size as interparietal. Frontal quadrangular. Complete supraorbital semicircles on both sides. Semicircles formed by 13 scales. Four enlarged supraoculars. Six superciliares overlapping on both sides. Ten upper and nine lower ciliary scales. Subocular elongated, larger than eye diameter, separated from supralabials by a single row of lorilabials. Supralabials of similar size. Eight lorilabials, with double and triple rows of scale organs. Eighth, seventh, sixth and fifth lorilabials in contact with subocular. Preocular separated from the lorilabial row by two scales. Postocular as large as preocular. Mental in contact with five scales, three infralabials (on each side) and two enlarged chin scales. Chin scales forming a longitudinal row of four enlarged scales separated one from the other by seven small scales. Gular scales rounded, flat and imbricated. 24 gulars between auditory meatus. Longitudinal neck fold without keeled scales, almost half in size of dorsal scales. Antehumeral pocket and folds well developed. 36 scales between auditory meatus and shoulder (counting along the post-auricular and longitudinal neck fold), 21 scales between the auditory meatus and the neck fold. Gular fold absent. Dorsal scales imbricated, slightly keeled, more conspicuous towards vertebral line. 53 dorsal scales between the occiput and groin level. 54 scales around midbody. Dorsal scales smooth towards flanks and belly. Ventral scales slightly wider than dorsal. 65 ventral scales between mental scale and cloaca; four precloacal pores. Supracarpals smooth and laminar with oval margins. Subdigital lamellae of fingers with three keels, formula I:8; II:12; III:17; IV:17; V:10 (right hand). Supradigital lamellae smooth and imbricated. Infracarpals and infratarsals keeled and imbricated. Supratarsals smooth and angular, but slightly keeled on fourth finger. Subdigital lamellae toe formula I:8; II:13; III:17; IV:21; V:13 (right foot).

Color pattern in life. (Figure 1) Dorsal color light brown with two paravertebral series of eight dark brown spots, more or less symmetrical, between occiput and pelvis, dark brown spots bordered by lighter scales. Lateral region of the body from cheek (postocular region) to the post-cloacal zone (tail base) with patches of emerald green scales on a bright yellow background, interrupted by dark brown transverse spots. Dorsal head brown with dark black spots. Area surrounding loreal, subocular, mental and ocular scales with bright yellow background color; five dark stripes on lateral head, one projects from eye to postocular and temporal region, one to mouth corner, two through subocular and labial region, and one through preocular and nasal. Dorsal limbs light brown with dark spots not reaching phalanges. Tail with dark brown subtriangular spots, which merge towards tip of tail. Ventral head, body and tail bright orange, with dark spots on head, and some on neck and belly.

**Figure 1.** Holotype (male, SVL = 64.5 mm, MUSM 31523) of *Liolaemus nazca* in dorsal (**A**) and ventral (**B**) views.

Color pattern in preservative. Dorsal background from neck to tip of tail is brown. On dorsal head, dark spots become more evident. Ventral region presents a whitish background coloration; dark spots accentuate and become more conspicuous.

Variation. (Figures 2 and 3). Variation in selected characters is summarized in Table 1. Sexual dichromatism present. Males have two paravertebral series of 6–8 dark brown spots on dorsum surrounded or not by white scales; body flanks with emerald green spots surrounded by yellow and dark brown spots; emerald green spots are present from lower temporal region of head to first third of tail; in young specimens emerald green spots are smaller and do not reach first third of tail. Males with orange or yellow on ventral surface of body, and limbs, with small dark spots in gular region, sometimes forming reticulations. Adult females have throat, belly and base of tail orange, yellowish or whitish, with or without dark spots or reticulations on belly.

Distribution and natural history (Figure 4). *Liolaemus nazca* is only known in Nazca province, Ica department, at elevations of 450–700 m. It was found on the ground or in shallow holes on the ground, mainly in hills ("Lomas") with low shrub vegetation and sandy soil, less frequently in areas with *Tillandsia* sp. In the summer, some individuals were active as early as 7:27 and as late as 16:22; on winter no individuals were observed. Body temperature of ten specimens ranged 22.7–34.0 ◦C (substrate temperature: 22.8–44.1 ◦C; air temperature: 21.4–31.0 ◦C). It was found together with *Ctenoblepharys adspersa, Microlophus* sp. and *Phyllodactylus gerrophygus*. This species is viviparous, one female had two embryos on each side at an advanced stage of development. On the Pacific coast, *L. nazca* is the northernmost species of *Liolaemus*.


**Table 1.** Variation in selected characters among type specimens of *Liolaemus nazca*. All specimens from Museo de Historia Natural Universidad Mayor de San Marcos.

 Vestigial precloacal pores.

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