A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS Author Torres-Carvajal, Omar Department of Vertebrate Zoologŋ, National Museum of Natural Historŋ, Smithsonian Institution, Washington, DC 20560, USA & Escuela de Biología, Pontificia UniƲersidad Católica del Ecuador, AƲenida 12 de Octubre ŋ Roca, Apartado 17 - 01 - 2184, Quito, Ecuador Torreso@si.edu text Herpetological Monographs 2007 2007-12-28 21 1 76 178 https://doi.org/10.1655/06-001.1 journal article 10.1655/06-001.1 14384794 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 ).