Stenocercus simonsii Boulenger, 1899

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 154-155

Stenocercus simonsii Boulenger ( Fig. 21 )

Stenocercus simonsii Boulenger, 1899:454 . Syntypes: BM 1946.8.11.73–74 , from ‘‘ Oña , 6500 ft (= 1981.2 m), [Provincia Azuay] Ecuador ̕̕; Burt and Burt, 1933:44; Peters, 1967:35; Etheridge, in Peters and Donoso-Barros, 1970:257; Fritts, 1974:64; Torres-Carvajal, 2000:31.

Diagnosis.— Stenocercus simonsii differs from all other species of Stenocercus except S. bolivarensis , S. carrioni , S. chlorostictus , S. crassicaudatus , S. empetrus , S. eunetopsis , and S. torquatus in having granular scales on the posterior surface of thighs, two caudal whorls per autotomic segment, mucronate caudal scales, and a distinct longitudinal row of enlarged vertebral scales. Of these species, only S. crassicaudatus , S. simonsii , and S. torquatus have granular dorsal scales on neck (imbricate, and smooth or keeled in remaining species). S. simonsii differs from S. crassicaudatus (character states in parentheses) by having a distinct black antehumeral collar that is incomplete middorsally (collar absent or faint). It is distinguished from S. crassicaudatus and S. torquatus by having fewer scales (79–102, X = 94.20) around midbody (97– 121, X = 108.87 in S. crassicaudatus ; 102– 137, X = 116.96 in S. torquatus ), and fewer (59–98, X = 73.75) vertebrals (83–97, X = 89.80 in S. crassicaudatus ; 83–115, X = 98.86 in S. torquatus ).

Description.—(1) Maximum SVL in males 88 mm ( Cadle, 1991); (2) maximum SVL in females 79 mm ( Cadle, 1991); (3) vertebrals 59–98; (4) paravertebrals 94–118; (5) scales around midbody 79–102; (6) supraoculars 6–9; (7) internasals four; (8) postrostrals 5–7; (9) loreals 2–4; (10) gulars 36–57; (11) subdigitals on Finger IV 24–28; (12) subdigitals on Toe IV 28–37; (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 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 on frontonasal region juxtaposed anteriorly; (20) preauricular fringe present; (21) antegular (continuous medially), antehumeral, gular, longitudinal, oblique, postauricular, and supra-auricular neck folds present; (22) lateral and dorsal nuchals similar in size; (23) posterior gulars cycloid, smooth, slightly 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 smooth, imbricate; (28) scales on posterior surfaces of thighs granular; (29) inguinal granular pocket present; (30) inguinal groove present; (31) preanals not projected; (32) tail not compressed laterally in adult males; (33) tail length 57–63% of total length; (34) caudal whorls per autotomic segment two; (35) caudals 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 1A, 1B, and 2B.

Color in life.—Dorsum grayish-green, light gray, or greenish brown with black transverse blotches; antehumeral region with black vertical bar; white stripe from subocular region to shoulder in some specimens; limbs and tail with alternating black and white transverse bars in some specimens; chin and gular region pale yellowish green in males, with scattered brown or black spots in females; gular fold black interiorly in males; ventral surfaces of body, limbs, and base of tail orange-yellow in males, yellowish beige in females ( Fritts, 1974; Torres-Carvajal, 2000).

Natural History.—This species is confined to rock piles and rock walls ( Fritts, 1974).

Distribution.— Stenocercus simonsii is known from the northern Andes in the western Cordillera and Saraguro inter-Andean basin in southern Ecuador ( Fig. 9 ). This species inhabits the upper valley of Río Jubones (Pacific drainage) at elevations of 1980–2500 m in Provincias Azuay and Loja (4 ° S–3 ° S). S. simonsii is sympatric with S. festae and S. rhodomelas in Azuay.

Figures

FIG. 21.—Eight species of Stenocercus. (A) S. ornatus (OTC); (B) S. percultus (MLU); (C) S. praeornatus (WED); (D) S. puŋango (LAC); (E) S. quinarius (CNO); (F) S. roseiƲentris (WED); (G) S. santander (MPR); (H) S. simonsii (WED).

FIG. 9.—Distribution of six species of Stenocercus in Ecuador.