Stenocercus marmoratus (Duméril and Bibron)

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 133-135

Stenocercus marmoratus (Duméril and Bibron)

( Fig. 20 )

Trachycyclus marmoratus Duméril and Bibron, 1837:356 . Holotype: MNHN 2513 , a juvenile from ‘‘province de Rio-Grande ̕̕ (restricted to Pampa Ruiz , between Valle Grande and El Pescado , Provincia de La Laguna, east of Chuquisaca, [Departamento Chuquisaca], Bolivia, by d̕ Orbigny [1847].)

Heterotropis (Trachycylus) marmorata Fitzinger, 1843:71 .

Stenocercus marmoratus Boulenger, 1885 a: 132 ; Burt and Burt, 1933:43; Fritts, 1974:57; Etheridge, in Peters and Donoso-Barros, 1970:256; Torres et al., 2000:129.

Stenocercus difficilis Werner, 1910:23 . Holotype: ZMH specimen destroyed in WWII, a male from ‘‘Cochabamba [Departamento Cochabamba], Bolivia̕̕; Burt and Burt, 1933:43. Synonymy fide Etheridge in Peters and Donoso-Barros, 1970:256.

Diagnosis.—Among species of Stenocercus with imbricate scales on the posterior surface of thighs, S. marmoratus and S. roseiventris are unique in having caudal scales with strongly projected mucrons. S. marmoratus is distinguished from S. roseiventris (character states in parentheses) by having a low and discontinuous vertebral crest (conspicuous and continuous), granular temporals (keeled and imbricate), lateral body scales half the size of dorsal body scales (laterals and dorsals similar in size), a prominent ventrolateral fold (fold inconspicuous or absent), 44–59 (X = 52.00) scales around midbody (55–82, X = 69.80), and by lacking a preauricular fringe (present).

Description.—(1) Maximum SVL in males 83 mm ( Torres et al., 2000); (2) maximum SVL in females 77 mm (n = 7); (3) vertebrals 44–66; (4) paravertebrals 51–68; (5) scales around midbody 44–59; (6) supraoculars 4–8; (7) internasals 2–4; (8) postrostrals five; (9) loreals 2–4; (10) gulars 23–30; (11) subdigitals on Finger IV 12–21; (12) subdigitals on Toe IV 16–23; (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 inconspicuous or absent; (21) antegular, antehumeral, gular, longitudinal, oblique, postauricular, and neck folds present (but see Torres et al., 2000); (22) lateral nuchals less than half the size of dorsal nuchals; (23) posterior gulars cycloid, smooth, slightly imbricate, not notched; (24) lateral and dorsal body scales similar in size; (25) anteriormost and posteriormost 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 present; (31) preanals not projected; (32) tail not compressed laterally in adult males; (33) tail length 56–60% of total length; (34) caudal whorls per autotomic segment two; (35) caudals strongly 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, Pattern 1B.

Color in life.—Dorsum grayish brown with dark brown cross bands and white or yellow blotches; white or yellow dorsolateral stripe, continuous or discontinuous, extending from subocular region to approximately midbody; flanks and sides of neck with white or yellow blotches; dark brown or black vertical bar anterior to fore limb in some specimens; throat charcoal with cream spots in some males; venter uniform cream, orange in some males (based on Torres et al. [2000] and a photograph taken by A. Muñoz.)

Natural History.—Females of S. marmoratus probably lay eggs twice a year. This species prefers rock outcrops and hides in crevices or underneath rocks ( Torres et al., 2000).

Distribution.— Stenocercus marmoratus is known from the eastern Cordilleras of the central and southern Andes between 24 ° S– 16 ° S ( Fig. 13 ). This species occurs at elevations of 1000–3350 m in Provincia Salta, Argentina, as well as Departamentos Chuquisaca, Cochabamba, Santa Cruz, and Tarija in Bolivia ( Cruz et al., 1996; Torres et al., 2000).

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. 13.—Distribution of seven species of Stenocercus in South America. Question mark indicates possible distribution of S. tricristatus.