Stenocercus dumerilii (Steindachner)

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 105-106

Stenocercus dumerilii (Steindachner)

( Fig. 14 )

Ophryoessoides dumerilii Steindachner, 1867: 33 . Holotype: NMW 16363 , a female from ‘‘Brazilien bei Pará̕̕ (restricted to surroundings of Belém, Pará, Brazil, by Cunha [1981]); Etheridge, 1966:88.

Liocephalus dumerilii Boulenger, 1885 a:170 .

Liocephalus dumerili Müller, 1912:14 .

Leiocephalus dumerilii Burt and Burt, 1933:27 ; Amaral, 1937:178; Cunha, 1961:86.

Ophryoessoides tricristatus (part) Etheridge in Peters and Donoso-Barros, 1970:215; Cunha, 1981:4.

Stenocercus dumerilii Frost, 1992:43 ; Avila-Pires, 1995:143; Cadle, 2001:184.

Diagnosis.—Among species of Stenocercus , S. dumerilii , S. quinarius , S. scapularis , S. sinesaccus , S. squarrosus , and S. tricristatus are unique in lacking caudal fracture planes. Of these species, only S. dumerilii , S. quinarius , S. squarrosus , and S. tricristatus have a pyramidal head, as well as enlarged, dorsally-projected posterior supraciliaries. S. dumerilii can be distinguished from S. tricristatus (character states in parentheses) by having distinctly pointed posterior supraciliaries (posterior supraciliaries blunt), two enlarged scales above tympanum (no enlarged scales above tympanum), tibia about as long as thigh (tibia shorter than thigh), and 41–50 (33) scales around midbody ( Avila-Pires, 1995). From S. quinarius and S. squarrosus (character states in parentheses) it can be distinguished by having a longer—53–58% of total length—tail (50–52% and 44–47%, respectively), keel on each dorsal scale prominent only distally (keel prominent throughout length of scale), 41–50 (47–56 and 46–53, respectively) scales around midbody, and a wider rostral scale ( Nogueira and Rodrigues, 2006).

Description.—(1) Maximum SVL in males 100 mm (n = 5); (2) maximum SVL in females 109 mm (n = 12); (3) vertebrals 24–30; (4) paravertebrals 33–41; (5) scales around midbody 41–50; (6) supraoculars 3–5; (7) internasals 6–7; (8) postrostrals 2–6; (9) loreals 2–4; (10) gulars 15–20; (11) subdigitals on Finger IV 12–18; (12) subdigitals on Toe IV 18–24; (13) posthumeral mite pocket absent; (14) postfemoral mite pocket absent; (15) parietal eye always visible through interparietal cornea; (16) scales on occipitoparietal region large, keeled or wrinkled, juxtaposed; (17) two projecting angulate temporals; (18) row of enlarged supraoculars occupying most of supraocular region absent; (19) scales on frontonasal region weakly 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, mucronate; (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 53–58% of total length; (34) caudal autotomic segments absent; (35) caudals not spinose; (36) dark brown stripe extending anterodorsally from subocular region to supraciliaries 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) five pairs of postxiphisternal inscriptional ribs not in contact midventrally, second pair of xiphisternal ribs not fused with xiphisternal rods.

Color in life (females only).—Dorsum brown with paired, blackish, triangular marks; blackish stripe extending anterodorsally from subocular region to supraciliaries; sides of neck with large black mark extending posteriorly to a level anterior to midbody; ventral surfaces with brown irregular pattern, iris verona brown ( Avila-Pires, 1995).

Natural History.—Food items of Stenocercus dumerilii include Arachnidae, Chilopoda, Coleoptera (adults and larvae), Diplopoda, Hemiptera, Hymenoptera , Lepidoptera (larvae), and Orthoptera ( Avila-Pires, 1995; Cunha, 1981). Females collected between January–June contained 2–6 oviductal eggs ( Cunha, 1981). A female kept in captivity laid eggs in September; incubation time and hatchling size varied between 88–112 days and 33–35 mm SVL, respectively ( Avila-Pires, 1995).

Distribution.— Stenocercus dumerilii occurs between 6 ° 30'S–0 ° in the Amazon basin in northeastern Brazil ( Fig. 13 ). It is known from Estados Pará and Maranhão at elevations of 0–100 m ( Andrade et al., 2003; Avila-Pires, 1995; Nogueira and Rodrigues, 2006).

Figures

FIG. 14.—Eight species of Stenocercus. (A) S. chota (LAC); (B) S. chrŋsopŋgus (MLU); (C) S. crassicaudatus (WED); (D) S. cupreus (MLU); (E) S. doellojuradoi (JAS); (F) S. dumerilii (TAP); (G) S. empetrus (RON); (H) S. festae (OTC).

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