Stenocercus frittsi Torres-Carvajal, 2005

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 121-122

Stenocercus frittsi Torres-Carvajal

Stenocercus frittsi Torres-Carvajal, 2005 b:471 . Holotype: KU 134181 , a male from ‘‘ Mariscal Cáceres , 12 ° 34'S, 74 ° 57'W, 3966 m, Departamento Huancavelica, Peru.̕̕

Stenocercus variabilis Fritts (part), 1974:65. Synonymy fide Torres-Carvajal, 2005 b:471.

Diagnosis.— Stenocercus frittsi is distinguished from all species of Stenocercus except S. variabilis in having granular scales on the posterior surface of thighs, imbricate and keeled lateral body scales, a distinct row of enlarged vertebral scales, unnotched gular scales, three caudal whorls per autotomic segment, gray or brown dorsal ground color, and distinct neck folds, of which the antegular fold is not continuous medially. The main difference between S. frittsi and S. variabilis is that the former species lacks a postfemoral mite pocket (distinct, deep pocket in S. variabilis ). In addition, S. frittsi is smaller than S. variabilis (maximum SVL = 79 mm and 94 mm in males, 66 mm and 76 mm in females, respectively), and it has on average fewer scales around the midbody (60–76, X = 65.14 and 61–86, X = 71.29), as well as fewer gulars (20–28, X = 22.63 and 26–33, X = 28.29), paravertebrals (59–90, X = 70.16 and 70–81, X = 75.71), and subdigitals on Toe IV (24–29, X = 26.98 and 26–35, X = 30.00).

Description.—(1) Maximum SVL in males 79 mm (n = 23); (2) maximum SVL in females 66 mm (n = 21); (3) vertebrals 48–71; (4) paravertebrals 59–90; (5) scales around midbody 60–76; (6) supraoculars 4–6; (7) internasals 4–5; (8) postrostrals 5–7; (9) loreals 2–4; (10) gulars 20–28; (11) subdigitals on Finger IV 16–22; (12) subdigitals on Toe IV 24–29; (13) posthumeral mite pocket present as one or more vertical folds or ridges; (14) postfemoral pocket absent; (15) parietal eye not visible through interparietal cornea; (16) scales on occipitoparietal region small, smooth, juxtaposed; (17) projecting angulate temporals absent; (18) row of enlarged supraoculars occupying most of supraocular region absent; (19) scales in frontonasal region weakly imbricate anteriorly; (20) preauricular fringe present; (21) antegular, antehumeral, gular, longitudinal, oblique, postauricular, and supra-auricular neck folds present; (22) lateral nuchals less than half the size of dorsal nuchals; (23) posterior gulars rhomboidal, smooth, imbricate, not notched; (24) lateral scales reduced in size, approximately half the size of dorsal body scales; (25) vertebrals larger than adjacent paravertebrals; (26) dorsolateral crest absent; (27) ventrals in adults smooth, imbricate, not mucronate; (28) scales on posterior surfaces of thighs granular; (29) inguinal granular pocket absent; (30) inguinal groove absent; (31) preanals not projected; (32) tail not compressed laterally in adult males; (33) tail length 59–65% of total length; (34) caudal whorls per autotomic segment three; (35) caudals not spinose; (36) dark stripe extending anterodorsally from subocular region to supraciliaries absent; (37) dark patch extensively covering gular region in 48% of adult females; (38) dark patch extensively covering gular region in 44% of adult males; (39) black patch on ventral surface of neck in adult males absent; (40) dark midventral longitudinal mark such as faint line, conspicuous stripe, or extensive patch in adult males absent; (41) dark patches on ventral surface of thighs in adult males absent; (42) postxiphisternal inscriptional ribs not in contact midventrally, Pattern 2B (specimens identified as S. variabilis in Torres-Carvajal [2004 a] correspond to S. frittsi .)

Color in life.—Dorsum dark gray with extensive black reticulations in males and grayish-beige with paired dull black blotches in juveniles and females; scales on dorsal surface of head black with white centers in some males; dorsal aspect of hind limbs light gray with dark blotches; angle of jaw and posttympanic area tan in some specimens; chin white with black reticulations or entirely black in males, and light gray without reticulations in females; ventral surface of body, hind limbs, and tail pale yellow in males and light gray in females; light blue midventral stripe in some males; posterior surface of thighs and ventral aspect of tail orange in some males ( Torres-Carvajal, 2005 b). There is considerable variation in the amount of dark pigment on the chin of both males and females of S. frittsi ( Fritts, 1974; Torres-Carvajal, 2005 b).

Distribution.— Stenocercus frittsi occurs between 13 ° S–12 ° S in the eastern Cordillera of the central Andes in Peru ( Fig. 10 ). This species is known from Departamentos Ayacucho and Huancavelica at elevations of 2350– 3966 m.

Figures

FIG. 10.—Distribution of six species of Stenocercus in Peru.