Stenocercus squarrosus Nogueira and Rodrigues

Stenocercus squarrosus Nogueira and Rodrigues, 2006:158 . Holotype: MZUSP 94056, a male from ‘‘ Chapada dos Gerais, Parque Nacional Serra das Confusões, 9 ° 13'S, 43 ° 29'W, Estado Piauí, Brazil.̕̕

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. Among other differences, S. squarrosus can be distinguished from S. dumerilii and S. tricristatus (character states in parentheses) by having a shorter—44–47% of total length— tail (53–58% and 68%, respectively) and more scales—46–53, X = 49.50—around midbody (41–50, X = 45.30 and 33, respectively; Nogueira and Rodrigues, 2006). It differs from S. quinarius mainly in having a shorter tail (44–47% and 50–52% of total length, respectively) and prominent dorsal, dorsolateral, and lateral crests (corresponding crests inconspicuous in S. quinarius; Nogueira and Rodrigues, 2006).

Description.—(1) Maximum SVL in males 88 mm (n = 6); (2) maximum SVL in females 88 mm (n = 6); (3) vertebrals 22–27; (4) paravertebrals 35–45; (5) scales around midbody 46–53; (6) supraoculars in holotype 4–5 (Fig. 6 in Nogueira and Rodrigues, 2006); (7) internasals 3–5; (11) subdigitals on Finger IV 13–15; (12) subdigitals on Toe IV 16–20; (13) posthumeral mite pocket absent; (14) postfemoral mite pocket absent; (15) parietal eye visible through interparietal cornea; (16) scales on occipitoparietal region large, keeled, juxtaposed; (18) row of enlarged supraoculars occupying most of supraocular region absent; (20) preauricular fringe present; (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; (32) tail not compressed laterally in adult males; (33) tail length 44– 47% of total length; (34) caudal autotomic segments absent; (35) caudals not spinose; (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.

Color in life.—Dorsum tan; dark brown stripe extending anterodorsally from subocular region to supraciliaries; gular and ventral areas light brown; tail with dark flecks; black spot on shoulder (Nogueira and Rodrigues, 2006).

Distribution.— Stenocercus squarrosus is only known from its type locality (9 ° 13'S, 43 ° 29'W) in Estado Piauí, Brazil (Fig. 13). This locality lies in a contact area between the Caatinga and Cerrado biomes (Nogueira and Rodrigues, 2006). This species is not known to occur in sympatry with other species of Stenocercus .