Stenocercus orientalis Fritts, 1972

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 140

Stenocercus orientalis Fritts

( Fig. 20 )

Stenocercus orientalis Fritts, 1972:14 . Holotype: KU 134466 , a male from ‘‘ Chachapoyas, 2340 m, Departamento Amazonas, Perú ̕̕; Fritts, 1974:60.

Diagnosis.— Stenocercus orientalis is distinguished from other species of Stenocercus except S. chrysopygus , S. cupreus , S. latebrosus S. modestus , and S. ornatissimus by having granular scales on the posterior surface of thighs, conspicuous antehumeral and oblique neck folds, a distinct mite pocket under oblique neck fold, and by lacking a vertebral crest. Of these species, S. orientalis is unique in having prominently keeled dorsal head scales.

Description.—(1) Maximum SVL in males 79 mm (n = 17); (2) maximum SVL in females 66 mm (n = 17); (3) vertebrals 44–58; (4) paravertebrals 48–62; (5) scales around midbody 46–59; (6) supraoculars 5–6; (7) internasals 3–5; (8) postrostrals 4–7; (9) loreals 2–3; (10) gulars 20–26; (11) subdigitals on Finger IV 16–21; (12) subdigitals on Toe IV 21–30; (13) posthumeral mite pocket present as one or more vertical folds or ridges; (14) postfemoral mite pocket distinct with slit-like opening; (15) parietal eye always visible through interparietal cornea; (16) scales on occipitoparietal region small, keeled, imbricate; (17) projecting angulate temporals absent; (18) row of enlarged supraoculars occupying most of supraocular region absent; (19) scales on frontonasal region weakly imbricate anteriorly; (20) no preauricular fringe present; (21) antehumeral and oblique neck folds present; (22) lateral nuchals less than half the size of dorsal nuchals; (23) posterior gulars cycloid, smooth, slightly imbricate, notched; (24) lateral and dorsal body scales similar in size; (25) vertebrals and adjacent paravertebrals similar in size; (26) dorsolateral crest absent; (27) ventrals smooth, imbricate; (28) scales on posterior surfaces of thighs granular; (29) inguinal granular pocket absent; (30) inguinal groove absent; (31) preanals not projected; (32) tail not strongly compressed laterally in adult males; (33) tail length 65–69% of total length; (34) caudal whorls per autotomic segment three; (35) caudals not spinose; (36) dark brown stripe extending anterodorsally from subocular region to supraciliaries absent; (37) dark patch extensively covering gular region of females absent; (38) dark patch extensively covering gular region of adult males absent; (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, Patterns 1B and 2C.

Color in life.—Dorsum brown with dark brown or black blotches, occasionally forming chevrons in males; light lateral stripe extends posteriorly from subocular region to dorsal aspect of tympanum and continues dorsolaterally to approximately the level of fore limb insertion; gular region and venter beige in males and grayish beige in females; ventrally, pelvic region and thighs yellow in males ( Fritts, 1972).

Natural History.—This species has been found in open areas at the bases of shrubs ( Fritts, 1972, 1974).

Distribution.— Stenocercus orientalis is known from the eastern Cordillera of the central Andes in northern Peru (6 ° S–5 ° S). This species occurs in the valley of Río Utcubamba (Atlantic drainage) at elevations between 2200–2900 m in Departamento Amazonas ( Fig. 19 ).

Figures

FIG. 20.—Eight species of Stenocercus. (A) S. marmoratus (AMU); (B) S. melanopŋgus (PVE); (C) S. modestus (MLU); (D) S. nigromaculatus (WED); (E) S. nubicola (PVE); (F) S. ochoai (WED); (G) S. orientalis (PVE); (H) S. ornatissimus (MLU).

FIG. 19.—Distribution of six species of Stenocercus in Ecuador and Peru.