Enyalioides rubrigularis Torres-Carvajal et al. 2009

Torres-Carvajal, Omar, Etheridge, Richard & Queiroz, Kevin De, 2011, A systematic revision of Neotropical lizards in the clade Hoplocercinae (Squamata: Iguania), Zootaxa 2752, pp. 1-44 : 30-31

Enyalioides rubrigularis Torres-Carvajal et al. 2009

Proposed standard English name: red-throated woodlizards

Proposed standard Spanish name: lagartijas de palo gargantirrojas

Enyalioides rubrigularis Torres-Carvajal et al. (2009:61) . Holotype: QCAZ 8483, from finca de Mesías San Martín (3º51'23'S, 78º51'53''W, 1154m), near Piuntza, Provincia Zamora Chinchipe, Ecuador.

Diagnosis. Enyalioides rubrigularis is the only species of Enyalioides in which males have a bright orange or red gular region without a dark patch. It also differs from other species of Enyalioides , except for E. praestabilis , in having the following combination of characters: smooth or feebly keeled ventrals; fewer than 32 dorsal scales in a transverse line between dorsolateral crests at midbody; and projecting scales on dorsum and limbs absent. It can be distinguished from E. praestabilis (character states in parentheses) by having larger scales on the ventral surface of the thighs in males; posteromedial aspect of gular region without black patch (black patch covering gular fold and posteromedial portion of gular region in some male specimens); and usually two femoral pores (usually one).

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 slightly more projecting than adjacent scales; (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 single middorsal crest; (9) dorsals keeled and homogeneous in size; (10) longitudinal, continuous row of raised, enlarged scales between dorsals and flank scales present; (11) scales on flanks small, with a few scattered enlarged scales; (12) ventrals smooth; (13) fore limb scales keeled dorsally, keeled or smooth ventrally; (14) hind limb scales keeled dorsally and keeled or smooth ventrally; scattered enlarged scales absent, though adult males have enlarged scales on the ventral surface of thighs; dorsal scales of pes homogeneous in size; (15) caudals heterogeneous, increasing in size posteriorly on each segment (5–7 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 ). Head with green, yellow, red, or black scales in males, brown or dark olive green in females; gulars and chin scales in males orange or red, with black margins; black gular patch in males absent; light spot posterior to tympanum present; faint stripe between tympanum and scapular region in some specimens; dorsal background green or brown in various tones, commonly mottled with greenish or yellowish scales; ventral surface of body, limbs, and tail white medially and light green laterally in males, brownish cream in females; iris brown or copper; metachromatism consiting of green tones being replaced by yellow or brown tones present (Torres-Carvajal et al. 2009).

Natural history. Most individuals of Enyalioides rubrigularis have been found sleeping at night with their heads facing up on vertical stems of 2–10 cm in diameter, or horizontal stems 2–3 cm in diameter. During the day juveniles seem to stay close to holes in the ground into which they retreat if approached (Torres-Carvajal et al. 2009). Two females (SVL = 91 and 104 mm; QCAZ 8458 and 8457, respectively) collected in June 2008 in Provincia Zamora Chinchipe, Ecuador, had two enlarged vitellogenic follicles on the left side (5.83–9.55 mm X 6.83– 10.03 mm) and one (QCAZ 8458) or two (QCAZ 8457) on the right side (6.64–9.06 mm X 7.44–11.70 mm).

Distribution. Enyalioides rubrigularis occurs on the eastern slopes of the Andes and western slopes of Cordillera del Cóndor in southern Ecuador at elevations of 1100–1460 m ( Fig. 5 ). This species is not known to occur in sympatry with other Enyalioides , and it might be restricted to the upper basins of the Zamora and Nangaritza rivers.

Remarks. Sequence divergence between Enyalioides rubrigularis (unpublished data) and E. praestabilis is 0.09 (maximum-likelihood corrected distance). Given that most interspecific distance values in Hoplocercinae are above 0.15 (Torres-Carvajal & de Queiroz 2009), sequence divergence between E. rubrigularis and E. praestabilis is relatively low. Genetic distance, preliminary maximum-likelihood phylogenetic analyses, and morphological evidence suggest that these two species are sister taxa.

Figures

FIGURE 3. Caudal segments from the anterior third of the tail of ten species of Hoplocercinae in lateral view. (A) Enyalioides cofanorum, (B) E. heterolepis, (C) E. laticeps, (D) E. microlepis, (E) E. oshaughnessyi, (F) E. palpebralis, (G) E. praestabilis, (H) E. rubrigularis, (I) E. touzeti, and (J) Morunasaurus annularis. Scale bars = 5 mm. Illustration by D. Paucar.

FIGURE 4. Photographs of live lizards representing twelve species of Hoplocercinae.

FIGURE 5. Distribution of Enyalioides cofanorum (dots) and E. rubrigularis (triangles).