Stenocercus pectinatus (Duméril and Bibron)

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 143-144

Stenocercus pectinatus (Duméril and Bibron)

Proctotretus pectinatus Duméril and Bibron, 1837:292 . Syntypes: MNHN 6868 , 6868A from ‘‘ Chili ̕̕; Burt and Burt, 1930:22; Burt and Burt, 1931:287; Burt and Burt, 1933:42; Peters and Donoso-Barros, 1970:241; Cei, 1986:277.

Liolaemus (Proctotretus) pectinatus Fitzinger, 1843:74 .

Ptygoderus pectinatus Gray, 1845:216 .

Proctotretus splendidus Girard, 1857:198 . Syntypes: ANSP 8546, MNHN 0074, USNM 5695, 565026, ‘‘Patagonia [Argentina].̕̕; ANSP 8546 erroneously listed as holotype by Malnate (1971:360); USNM 5695 herein designated as lectotype . Synonymy fide Boulenger, 1885 a:159.

Saccodeira pectinata Boulenger, 1885 a:159 ; Koslowsky, 1898:183.

Stenocercus pectinatus Frost, 1992:43 ; Cei, 1993:308.

Diagnosis.—Among species of Stenocercus that lack posthumeral and postfemoral mite pockets and have imbricate scales on the posterior surface of thighs (i.e., S. azureus , S. doellojuradoi , S. dumerilii , S. pectinatus , S. quinarius , S. sinesaccus , S. squarrosus and S. tricristatus ), those species formerly assigned to ‘‘ Proctotretus ̕̕ (i.e., S. azureus , S. doellojuradoi and S. pectinatus ) are unique in having posteriorly projected preanals that form a denticulate border, and two longitudinal rows of lorilabials between the anterior portion of the subocular and the corresponding supralabials. S. pectinatus can be distinguished from S. azureus by having notched and smooth ventrals and gulars (unnotched and strongly keeled in S. azureus ). It can be distinguished from S. doellojuradoi by having a distinct antehumeral fold, and the mental usually in contact with the first pair of sublabials. In addition, S. pectinatus is unique among species of Stenocercus in having four instead of five phalanges in Finger IV, which makes this finger shorter than Finger III.

Description.—(1) Maximum SVL in males 69 mm (n = 11); (2) maximum SVL in females 66 mm (n = 16); (3) vertebrals 31–37; (4) paravertebrals 37–49; (5) scales around midbody 33–46; (6) supraoculars 4–6; (7) internasals 4–5; (8) postrostrals 4–5; (9) loreals 1–3; (10) gulars 16–22; (11) subdigitals on Finger IV 7–12; (12) subdigitals on Toe IV 16–23; (13) posthumeral mite pocket absent; (14) postfemoral mite pocket absent; (15) parietal eye always visible through interparietal cornea; (16) scales on occipitoparietal region small, keeled, imbricate; (17) projecting angulate temporals absent; (18) row of enlarged supraoculars occupying most of supraocular region absent; (19) scales on frontonasal region imbricate anteriorly; (20) preauricular fringe present; (21) antehumeral fold present; (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 present; (27) ventrals smooth, imbricate; (28) scales on posterior surfaces of thighs keeled, imbricate; (29) inguinal granular pocket absent; (30) inguinal groove absent; (31) preanals projected; (32) tail not compressed laterally in adult males; (33) tail length 52–59% of total length; (34) caudal whorls per autotomic segment two; (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 adult males absent; (41) dark patches on ventral surface of thighs in adult males absent; (42) postxiphisternal inscriptional ribs not in contact midventrally, Patterns 1B, 1C, 2C, 2D, and 3.

Color in life.—Dorsal background grayish brown and green; dorsum between dorsolateral crests with three longitudinal series of dark brown marks posteriorly bordered with white; dorsum of head with broad, brown interorbital bar, as well as brown occipitoparietal marks and one or two large brown patches on frontonasal region; ventral surfaces whitish cream; gular region in males with bright-orange transverse band ( Cei, 1986, 1993).

Natural History.—Among southwestern populations in Provincia Buenos Aires, Argentina, eggs are probably laid around December ( Gallardo, 1970).

Distribution.— Stenocercus pectinatus occurs between 40 ° S–25 ° S in the Atlantic lowlands of Argentina marking the southern limit of the distribution of Stenocercus ( Figs. 1 , 11 ). This species is known from elevations of 0– 1100 m in Provincias Buenos Aires, Córdoba, La Pampa, Patagonia, Río Negro, San Luis, and Santa Fe ( Avila, 1999; Cardinale and Vignolo, 1996).

Figures

FIG. 1.—Distribution of Stenocercus in South America.

FIG. 11.—Distribution of six species of Stenocercus in South America.