Enyalioides microlepis O'Shaughnessy 1881

Enyalioides microlepis (O'Shaughnessy 1881)

Proposed standard English name: small-scaled woodlizards

Proposed standard Spanish name: lagartijas de palo microescamadas

Enyalius microlepis O’Shaughnessy (1881:238). Syntypes: BMNH 60.6.16.8 (RR 1946.8.5.76), 58.7.25.17 (RR 1946.8.5.57), 80.12.8.36-36a (RR 1946.8.9.5-6) from “Sarayacu, [03º00'N, 78º09'W, 400 m, Provincia Pastaza], Ecuador.” Enyalioides microlepis Boulenger (1885:115); Burt & Burt (1930:10; 1931:267; 1933:24); Peters & Donoso-Barros (1970:115).

Diagnosis. This species can be distinguished from other species of Enyalioides by the combination of the following characters: enlarged projecting scales on dorsum (except vertebrals), flanks, or limbs absent; dorsal scales in a transverse row between dorsolateral crests at midbody more than 40; and ventrals strongly keeled. Among other species of Enyalioides occuring east of the Andes, E. microlepis is similar morphologically to specimens of E. cofanorum that lack the projecting dorsal scales characteristic of that species. E. microlepis differs from those specimens of E. cofanorum (character states in parentheses) in lacking conspicuous dorsolateral crests between hind limbs (always conspicuous), and in having a maximum SVL of 127 mm in males (107 mm) and 116 mm in females (109 mm).

Description. (1) dorsal head scales conical or multicarinate, strongly projecting dorsally; (2) posterior superciliaries not enlarged relative to adjacent scales; (3) scales on lateral edge of skull roof just posterior to superciliaries more projecting than adjacent scales; the projection is more pronounced in adults; (4) one or two enlarged pretympanic scales present; (5) gular scales conical or multicarinate, strongly projecting ventrally; (6) dorsal and lateral neck scales similar in size, mostly granular or conical; (7) vertebrals larger than adjacent dorsals, forming distinct raised middorsal crest that extends onto tail as a pair of crests; (8) nuchal region with continuous and usually (92.9%) paired middorsal crest; (9) dorsals distinctly keeled and homogeneous in size; (10) continuous longitudinal row of raised, enlarged scales between dorsals and flank scales present; (11) scales on flanks keeled, usually (78.6%) homogeneous in size; (12) ventrals keeled; (13) fore limb scales keeled dorsally and ventrally; (14) hind limb scales keeled dorsally and ventrally; scattered enlarged scales absent; dorsal scales of pes homogeneous in size; (15) caudals heterogeneous, increasing in size posteriorly on each segment (6–8 scales in lateral view), not modified as conspicuous spines (Fig. 3); (16) tail compressed laterally. Meristic and morphometric characters are presented in Table 1.

Coloration in life (Fig. 4). Adult males (QCAZ 8223): dorsal surface and sides of head yellowish brown with scattered dark brown irregular marks; labials yellowish cream with brown margins; dorsum and flanks creamish brown with a dense dark brown reticulation; sides of neck same as flanks, with a bright white blotch posterodorsal to tympanum; dorsal aspect of limbs cream with dark greenish brown flecks; chin and lateral parts of gular region with cream and light brown scales; narrow black gular patch extending anteriorly from gular fold to level of temporal region; light blue patch surrounding the black gular patch and extending to level of eyes anteriorly and to ventral part neck sides laterally; ventral surface of body and limbs cream with a few greenish brown flecks on limbs; tail cream with scattered brown marks ventrally, and with faint alternate brownish cream and dark brown transverse bands laterally and dorsally; iris yellowish brown with golden ring around pupil (color photograph).

Adult females (QCAZ 8284): dorsal surface and sides of head dark brown; most loreals and suboculars brownish cream; dorsum and flanks yellowish brown with a dense dark brown reticulation forming a longitudinal series of eight yellowish brown blotches between dorsum and flanks; dark brown reticulation breaks apart on ventral aspect of flanks; sides of neck with a bright white blotch posterodorsal to tympanum; dorsal aspect of limbs dark brown with yellowish brown spots; posterior aspect of gular region light gray; chin, anterior and lateral aspects of gular region, and ventral surface of body, limbs, and tail cream with a few scattered brown flecks; tail with alternate narrow yelowish brown and wide dark brown transverse bands laterally and dorsally; iris golden brown with golden ring around pupil (color photograph).

Natural history. This species has been found under logs, or sleeping head-up on sticks or horizontally on branches less than 1 m above the ground (F. Ayala field notes, 2008).

Distribution. Enyalioides microlepis occurs east of the Andes in southern Colombia, Ecuador, and northern Peru (Fig. 7) at elevations between 100–1000 m. This species is known to occur in sympatry with E. laticeps and E. praestabilis in eastern Ecuador. However, this species also might be sympatric with both E. laticeps and E. praestabilis east of the Andes in southern Colombia and northern Peru.

Remarks. As noted by Wiens & Etheridge (2003), several authors have confused Enyalioides microlepis with E. oshaughnessyi (Peters & Donoso-Barros 1970; Almendáriz 1992; Torres-Carvajal 2001). Besides the differences noted in the diagnoses provided in this manuscript, the latter species is restricted to the western slopes of the Andes and adjacent Pacific lowlands in Colombia and Ecuador, whereas E. microlepis occurs in the upper Amazon basin in Colombia, Ecuador, and Peru.