Stenocercus chota Torres-Carvajal, 2000

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 98-100

Stenocercus chota Torres-Carvajal ( Fig. 14 )

Stenocercus chota Torres-Carvajal, 2000:13 . Holotype: QCAZ 3768 , a male from ‘‘ Panamerican hwy 5 km E Chota, 00 ° 28'N, 78 ° 01'W, Valle del Chota , Provincia Imbabura, Ecuador. ̕̕

Diagnosis.— Stenocercus chota differs from all other species of Stenocercus except S. angel , S. festae , S. guentheri , and S. nigromaculatus by having imbricate scales on posterior surface of thighs, smooth ventrals, a posthumeral mite pocket consisting of a shallow depression with a wide opening (more distinct in adult specimens), small scales on occipitoparietal region, and supraoculars of similar size. Of these species, S. nigromaculatus is unique in having an antehumeral fold. S. chota differs from S. festae and S. guentheri in adult males lacking a distinct, black transverse band on ventral surface of neck, which is variably present in adult males of those two species. In addition, S. guentheri has more scales around midbody than S. chota ( Torres-Carvajal, 2000) . S. chota can be distinguished from S. angel by having a distinct black midventral stripe in most adult males (polymorphic), and large black spots on gular region of juveniles and females ( Torres-Carvajal, 2000). In addition, the dorsum of adult males in S. chota is generally brown, whereas some adult males of S. angel have a dark green dorsum.

Description.—(1) Maximum SVL in males 97 mm (n = 17); (2) maximum SVL in females 65 mm (n = 20); (3) vertebrals 39–50; (4) paravertebrals 55–74; (5) scales around midbody 45–59; (6) supraoculars 4–6; (7) internasals 2–4; (8) postrostrals 4–5; (9) loreals 2–4; (10) gulars 18–25; (11) subdigitals on Finger IV 14–20; (12) subdigitals on Toe IV 23–31; (13) posthumeral mite pocket present as a shallow depression with a wide opening; (14) postfemoral mite pocket distinct with slit-like opening; (15) parietal eye visible through interparietal cornea in 92% of specimens; (16) scales on occipitoparietal region small, keeled or multicarinate, and juxtaposed or subimbricate; (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) preauricular fringe present; (21) neck folds absent; (22) lateral and dorsal nuchals similar in size; (23) posterior gulars rhomboidal, smooth, imbricate, not notched; (24) lateral and dorsal body scales similar in size; (25) vertebrals larger than adjacent paravertebrals; (26) dorsolateral crest absent; (27) ventrals smooth, imbricate; (28) scales on posterior surfaces of thighs keeled, imbricate; (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 60–65% 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 82% of adult males; (41) dark patches on ventral surface of thighs in 12% of adult males; (42) postxiphisternal inscriptional ribs not in contact midventrally, Pattern 2A.

Color in life.—Dorsum grayish brown to dark brown with or without transverse dark irregular bars arranged longitudinally from neck to base of tail; white and dark brown spots scattered over dorsum and flanks in males; yellow blotch on axillary region in some males; limbs with dark brown reticulations dorsally; loreal and subocular regions white or cream; gular region reddish cream or dark brown in males and cream with large black spots in females; venter light blue, slightly orange on the sides, with black midventral stripe in some males; venter in females cream; pelvic region, base of tail, and thighs in some males bright yellow ventrally; iris bronzed green or bronzed red.

Natural History.—Females lay two eggs; gravid females and neonates have been collected during June–July ( Torres-Carvajal, 2000). This species has been collected in undisturbed areas, as well as very disturbed areas such as sugar cane plantations.

Distribution.— Stenocercus chota occurs on the northern Andes in northern Ecuador ( Fig. 8 ). It is known from elevations of 1575–1940 m in the upper valley of Río Mira (Pacific drainage) in Provincias Carchi, Esmeraldas, and Imbabura. The distribution lies between 0 ° 20'N–0 ° 40'N.

Figures

FIG. 14.—Eight species of Stenocercus. (A) S. chota (LAC); (B) S. chrŋsopŋgus (MLU); (C) S. crassicaudatus (WED); (D) S. cupreus (MLU); (E) S. doellojuradoi (JAS); (F) S. dumerilii (TAP); (G) S. empetrus (RON); (H) S. festae (OTC).

FIG. 8.—Distribution of six species of Stenocercus in Colombia and Ecuador.