Stenocercus angel Torres-Carvajal, 2000

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 83-85

Stenocercus angel Torres-Carvajal ( Fig. 7 )

Stenocercus angel Torres-Carvajal, 2000:9 . Holotype: QCAZ 3733 , a male from ‘‘ 8 km NE El Angel on road to Tulcán, 00 ° 40'N, 77 ° 52'W, Provincia Carchi, Ecuador.̕̕

Stenocercus guentheri (part) Castro and Granados, 1993:296.

Diagnosis.— Stenocercus angel differs from all other species of Stenocercus except S. chota , 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. angel 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. angel ( Torres-Carvajal, 2000) . S. angel can be distinguished from S. chota by lacking (1) a distinct black midventral stripe in most adult males (polymorphic), and (2) large black spots on gular region of juveniles and females ( Torres-Carvajal, 2000). Moreover, some adult males of S. angel have a dark green dorsum, a condition not present in S. chota (dorsum brown).

Description.—(1) Maximum SVL in males 87 mm (n = 21); (2) maximum SVL in females 76 mm (n = 9); (3) vertebrals 39–56; (4) paravertebrals 51–75; (5) scales around midbody 49–68; (6) supraoculars 4–6; (7) internasals 1–4; (8) postrostrals 3–6; (9) loreals 2–3; (10) gulars 19–27; (11) subdigitals on Finger IV 13–22; (12) subdigitals on Toe IV 20–28; (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 76% 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 or slightly keeled, 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 weakly compressed laterally in adult males; (33) tail length 59–69% 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 in 14% 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 57% of adult males; (41) dark patches on ventral surface of thighs in adult males absent; (42) postxiphisternal inscriptional ribs not in contact midventrally, Pattern 2A.

Color in life.—Dorsal background dark brown in females and juveniles, dark brown or dark green in adult males; several transverse brown bars over vertebral line, from neck to base of tail; gular region black or bluish green in adult males; ventral surface of body, tail, and limbs with irregular yellow and green spots in some adult males, and yellowish-brown with scattered brown flecks in females; ventral aspect of pelvic region, base of tail, and thighs yellow in some male specimens.

Natural History.—Clutch size in S. angel is two eggs ( Castro and Granados, 1993; Torres-Carvajal, 2000). Weight of two eggs deposited on 4 April 1987 was 1.3 g and 1.4 g, respectively; field observations suggest remarkable territoriality in this species ( Castro and Granados, 1993). In Ecuador, S. angel has been found in mesic environments (paramo) usually basking on the ground near the base of the spiny bromeliad Puya, which is used by this species as shelter ( Torres-Carvajal, 2000).

Distribution.— Stenocercus angel occurs in the northern Andes between 0 ° 30'N–1 ° 30'N ( Fig. 8 ). This species is known from elevations between 2400–3560 m in southern Colombia (Departamentos Cauca and Nariño; Castro and Granados, 1993) and northern Ecuador (Provincia Carchi; Torres-Carvajal, 2000).

Figures

FIG. 7.—Eight species of Stenocercus. (A) S. angel (LAC); (B) S. angulifer (FAY); (C) S. apurimacus (WED); (D) S. azureus (SCA); (E) S. boettgeri (MLU); (F) S. boliƲarensis (FCA); (G) S. caducus (LSI); (H) S. chlorostictus (MLU).

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