Stenocercus nigromaculatus Noble, 1924

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 137-138

Stenocercus nigromaculatus Noble

( Fig. 20 )

Stenocercus nigromaculatus Noble, 1924:112 . Holotype: MCZ 17975 , a male from ‘‘ Huancabamba , Province of Piura [Departamento Piura], Peru ̕̕; Burt and Burt, 1931:288; Burt and Burt, 1933:43; Peters, 1967:35; Fritts, 1974:59.

Diagnosis.— Stenocercus nigromaculatus differs from all other species of Stenocercus except S. angel , S. chota , S. festae , and S. guentheri 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 and black patches on the ventral surface of thighs in adult males. In addition, S. nigromaculatus is smaller in size, with males reaching up to 77 mm SVL ( S. angel = 87 mm, S. chota = 97 mm, S. festae = 102 mm, S. guentheri = 96 mm) and females up to 64 mm SVL ( S. angel = 76 mm, S. chota = 65 mm, S. festae = 79 mm, S. guentheri = 73 mm).

Description.—(1) Maximum SVL in males 77 mm (n = 16); (2) maximum SVL in females 64 mm (n = 19); (3) vertebrals 43–60; (4) paravertebrals 52–71; (5) scales around midbody 45–60; (6) supraoculars 4–7; (7) internasals 2–4; (8) postrostrals 3–6; (9) loreals 2–4; (10) gulars 18–24; (11) subdigitals on Finger IV 14–20; (12) subdigitals on Toe IV 22–31; (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 always visible through interparietal cornea; (16) scales on occipitoparietal region small, keeled or multicarinate, 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) preauricular fringe present; (21) antehumeral fold present; (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 smooth or 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 66–70% 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 81% of adult males; (41) dark patches on ventral surface of thighs in 81% of adult males; (42) postxiphisternal inscriptional ribs not in contact midventrally, Patterns 1B, 2A, and 2B.

Color in life.—Dorsum greenish brown with one pair of light dorsolateral stripes that are more conspicuous in females (these stripes fade posterior to shoulder in males); longitudinal series of dark brown transverse bars over vertebral line (less conspicuous in females, usually as a series of spots); black vertical bar on shoulder in males; throat with indistinct pale brown mottling; venter yellowish or greenish, slightly iridescent; in males, black midventral stripe extending to ventral aspect of hind limbs; pink suffusion on ventral aspect of tail ( Noble, 1924).

Natural History.—This species has been observed basking and foraging in rows of Agave plants and around bases of shrubs ( Fritts, 1974), as well as in rock-walls or piles of rocks ( Noble, 1924).

Distribution.— Stenocercus nigromaculatus occurs north of the western Cordillera of the central Andes in Peru between 6 ° S–5 ° S ( Fig. 19 ). This species occurs in the valley of Río Huancabamba (Atlantic drainage) at elevations of 1900–2300 m in Departamento Piura ( Fritts, 1974).

Figures

FIG. 20.—Eight species of Stenocercus. (A) S. marmoratus (AMU); (B) S. melanopŋgus (PVE); (C) S. modestus (MLU); (D) S. nigromaculatus (WED); (E) S. nubicola (PVE); (F) S. ochoai (WED); (G) S. orientalis (PVE); (H) S. ornatissimus (MLU).

FIG. 19.—Distribution of six species of Stenocercus in Ecuador and Peru.