Stenocercus fimbriatus Avila-Pires, 1995

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 117-119

Stenocercus fimbriatus Avila-Pires ( Fig. 18 )

Stenocercus fimbriatus Avila-Pires, 1995:151 . Holotype: TCWC 41795 , a male from ‘‘ Mishana , Iquitos Region, Departamento Loreto, Peru ̕̕; Cadle, 2001:184.

Ophryoessoides aculeatus (part) Dixon and Soini, 1975:32, 1986:37.

Diagnosis.—Among species of Stenocercus with strongly keeled ventrals and laterally oriented nostrils, S. fimbriatus is similar to S. aculeatus , S. angulifer , S. caducus , S. prionotus , and S. scapularis in having a distinct posthumeral mite pocket. Of these species, only S. caducus , S. fimbriatus , and S. prionotus lack a postfemoral mite pocket. S. fimbriatus can be distinguished from S. prionotus and S. caducus by lacking an axillary flap covering the antehumeral mite pocket ( Cadle, 2001), and by having a row of enlarged, projecting scales on the dorsal aspect of thighs ( Avila-Pires, 1995). In addition, dorsal head scales in S. fimbriatus are smooth or wrinkled, whereas these scales are strongly keeled in S. caducus and S. prionotus .

Description.—(1) Maximum SVL in males 74 mm ( Cadle, 2001); (2) maximum SVL in females 91 mm ( Cadle, 2001); (3) vertebrals 37–52; (4) paravertebrals 42–52; (5) scales around midbody 39–51; (6) supraoculars 4–6; (7) internasals 4–7; (8) postrostrals 4–7; (9) loreals 2–6; (10) gulars 17–25; (11) subdigitals on Finger IV 12–16; (12) subdigitals on Toe IV 19–27; (13) posthumeral mite pocket present as a deep depression; (14) postfemoral mite pocket absent; (15) parietal eye not visible through interparietal cornea; (16) scales on occipitoparietal region large, smooth or wrinkled, weakly imbricate; (17) projecting angulate temporals absent; (18) one row of enlarged supraoculars occupying most of supraocular region; (19) scales on frontonasal region imbricate anteriorly; (20) preauricular fringe inconspicuous or absent; (21) neck folds absent; (22) lateral and dorsal nuchals similar in size; (23) posterior gulars rhomboidal, projected posteriorly, strongly keeled and imbricate, not notched; (24) lateral and dorsal body scales similar in size; (25) vertebrals larger than adjacent paravertebrals; (26) dorsolateral crest present; (27) ventrals keeled, 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 61–68% 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 always present; (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 continuous midventrally, Patterns 6A and 6B (KU 212628 identified as S. aculeatus in Torres-Carvajal [2004 a] corresponds to S. fimbriatus .)

Color in life.—Dorsum golden brown with thin, dark brown V-shaped marks arranged longitudinally from neck to tail, and one pair of black spots between fore limbs; dorsal and lateral aspects of head and neck golden brown with a thin, dark brown interorbital bar and a dark brown stripe extending anterodorsally from subocular region to supraciliaries; flanks and limbs dark brown or black; cream line between comisure of mouth and base of fore limb; cream vertical line between insertion of fore limb and dorsolateral crest; gular region with short, oblique, cream lines starting on labials; venter walnut brown to vinaceous pink (more intense in males) with light spots; iris orange brown ( Avila-Pires, 1995; Dixon and Soini, 1975, 1986).

Natural History.— Stenocercus fimbriatus takes advantage of its cryptic coloration to escape predators by ‘‘freezing̕̕ when against a background of dead leaves becoming difficult to see ( Avila-Pires, 1995; Dixon and Soini, 1975, 1986).

Distribution.— Stenocercus fimbriatus occurs in the western Amazon basin and eastern slopes of the central Andes between 10 ° S–4 ° S ( Fig. 11 ). This species is known from altitudes of 300–1000 m in Brazil (Estados Acre and Amazonas) and Peru (Departamentos Huánuco, La Libertad, Loreto, Madre de Dios, and Ucayali). Lehr and von May (2004) erroneously reported S. fimbriatus for Departamento Junín based on a specimen of S. scapularis (MTD 45664). Similarly, Langstroth (2005) reported this species for Bolivia based on the assumption that specimens collected in Tumi Chucua (Bolivia: Beni), and identified as S. aculeatus by Fugler (1986), corresponded to S. fimbriatus ; these specimens (USNM 280246–51) are actually paratypes of S. prionotus ( Cadle, 2001) . S. fimbriatus is sympatric with S. prionotus (Peru: Loreto) and S. roseiventris (Peru: Loreto, Madre de Dios).

Figures

FIG. 18.—Eight species of Stenocercus. (A) S. fimbriatus (JCA); (B) S. formosus (MLU); (C) S. guentheri (LAC); (D) S. humeralis (OTC); (E) S. imitator (PVE); (F) S. iridescens (RWM); (G) S. lache (JMR); (H) S. limitaris (PVE).

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