Stenocercus rhodomelas (Boulenger)

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 150-151

Stenocercus rhodomelas (Boulenger)

Liocephalus rhodomelas Boulenger, 1899:455 . Syntypes: BM 1946.8.29.77–80 , from ‘‘ Oña [Provincia Azuay], Ecuador.̕̕

Leiocephalus rhodomelas Burt and Burt, 1933:29 .

Ophryoessoides rhodomelas Etheridge, 1966: 88 ; Peters, 1967:28; Etheridge, in Peters and Donoso-Barros, 1970:214.

Stenocercus rhodomelas Fritts, 1974:63 ; Torres-Carvajal, 2000:29.

Diagnosis.— Stenocercus rhodomelas is distinguished from other species of Stenocercus except S. ornatus and S. percultus by having imbricate scales on the posterior surface of thighs, smooth ventrals, deep posthumeral and postfemoral mite pockets, and keeled dorsal head scales. Of these species, S. rhodomelas is unique in lacking an antehumeral fold (weakly to moderately developed in S. percultus and S. ornatus ). In addition, only adult males of S. rhodomelas and S. percultus have the gular region extensively covered in black. However, the black patches on the ventral surfaces of hind limbs characteristic of S. rhodomelas adult males are absent in S. percultus .

Description.—(1) Maximum SVL in males 93 mm (n = 24); (2) maximum SVL in females 73 mm (n = 28); (3) vertebrals 43–55; (4) paravertebrals 49–61; (5) scales around midbody 43–58; (6) supraoculars 3–6; (7) internasals 2–4; (8) postrostrals 3–6; (9) loreals 2–3; (10) gulars 17–21; (11) subdigitals on Finger IV 14–21; (12) subdigitals on Toe IV 22–30; (13) posthumeral mite pocket present as a deep depression; (14) postfemoral mite pocket distinct with slit-like opening; (15) parietal eye always visible through interparietal cornea; (16) scales on occipitoparietal region small, keeled or wrinkled, juxtaposed; (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, 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 strongly compressed laterally in adult males; (33) tail length 60–66% 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 always present; (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 always present; (41) dark patches on ventral surface of thighs in adult males always present; (42) postxiphisternal inscriptional ribs not in contact midventrally, Patterns 2A and 2B.

Color in life.—Dorsum dark brown with scattered pink, cream, or black scales and a black V-shaped mark between fore limbs; some vertebrals yellow in males; shoulder with black blotch; labials and rostral black in most specimens; gular region with large black patch in males and brown scattered flecks in females; throat pink and pectoral region with black patch extending posteriorly as a midventral stripe in males; ventral surfaces of pelvic region and hind limbs black in males; black ventral triangular mark pointing posteriorly on base of tail in some males; ventral surface of tail pink proximally and cream distally in males ( Torres-Carvajal, 2000).

Natural History.— Fritts (1974) observed this species on large rocks and on the ground at the base of cacti in xeric areas with sparse vegetation. I have seen this species on the ground near small shrubs.

Distribution.— Stenocercus rhodomelas occurs in southern Ecuador (northern Andes) between 3 ° 30'S–3 ° S on the western slopes of the western Cordillera, as well as the Saraguro inter-Andean basin ( Fig. 8 ). This species occupies the upper valley of Río Jubones (Pacific drainage) at elevations of 730–2100 m in Provincias Azuay and Loja. S. rhodomelas is sympatric with S. simonsii (Azuay) and possibly S. festae and S. iridescens ( Fritts, 1974; Torres-Carvajal, 2000).

Figures

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