Alopoglossus meloi, Ribeiro-Júnior, 2018

Ribeiro-Júnior, Marco Antônio, 2018, A new species of Alopoglossus lizard (Squamata, Alopoglossidae) from the Southern Guiana Shield, northeastern Amazonia, with remarks on diagnostic characters to the genus, Zootaxa 4422 (1), pp. 25-40 : 26-33

Alopoglossus meloi sp. nov.

( Figs. 1 , 2 , 3A , 4 , 5 ; Table 1)

Alopoglossus angulatus Ávila-Pires (1995: 308) .

Holotype. MPEG 24372 ( Figs. 1 , 2 ), an adult male, collected on 29 January 2007 by E. Pereira and team, at Porto Trombetas, Aramã Plateau (1°52'25"S, 56°24'55"W), Terra Santa municipality, State of Pará, Brazil. Field number R138.

Paratypes. Brazil: State of Amazonas: CZPB-RP 0 0 27, adult female, collected on 22 September 2011 by A. Almeida, D. Oliveira, L. Frazão, S. Marques and T. Hrbek, at São José do Jatobá Village, Igarapé do Tabocal, eastern Jatapú River, São Sebastião do Uatumã (1°55'53"S, 58°15'21"W), field number CZPB-2940 ; MHNCI 13588 , adult female, collected on June 2009 by F. Oliveira, at Saracá-Taquera National Forest , Oriximiná (1°44'11"S, 56°24'36"W) ; MPEG 29381, adult female, collected on 0 5 October 2009 by R. Ávila, at Marajatuba, Urucará (2°22'47"S, 57°38'42"W), field number M3 R74. State of Pará: MPEG 15348 , MPEG 16201 , adult female and young respectively, collected on 0 6 December and 11 December 1988 by M. Hoogmoed, T. Ávila Pires and R. Rocha, at Cruz Alta, 6 km south of Trombetas River, Oriximiná (1°30'56"S, 56°45'51"W), field number TCAP 1153 and TCAP 1213 ; MPEG 28271 , adult male, collected on 29 June 2008 by R. Pinto and team, at Porto Trombetas, Saracá-Taquera National Forest , Saracá Plateau, Oriximiná (1°41'20"S, 56°29'35"W), field number R 212 ; MPEG 19880, adult male, collected on 10 October 2001 by U. Galatti and J. Bernardi, at Porto Trombetas, Saracá Mine, in a reforestation area, Oriximiná (1°40'41"S, 56°23'57"W), field number TROMBE 058; MPEG 24373, adult female, collected on 0 5 February 2007 by E. Pereira and team, at Porto Trombetas, Greig Plateau, Terra Santa (1°50'39"S, 56°31'42"W), field number R 201.

Referred specimens. 14 specimens from Brazil ( Appendix ).

Diagnosis. AlopogloSSuS meloi sp. nov. is distinguished from all other species in the genus AlopogloSSuS by the combination of the following characters: (1) scales on sides of neck keeled, imbricate (at least posterior ones phylloid); (2) four pairs of chin shields (well-developed fourth pair); (3) third pair of chin shields irregularly trapezoidal (heptagonal), separated from gulars by large scales; (4) scales on sides of neck in 6–8 transverse rows; (5) gulars smaller, but similar in shape to dorsals, pointed, imbricate, phylloid (except the first transverse row is smooth, almost rounded); (5) keeled temporal scales; (6) ventrals smooth to feebly keeled, mucronate and imbricate, with posterior margin bluntly pointed; (7) total number of femoral pores 20–23 in males.

Comparisons with other species. AlopogloSSuS meloi sp. nov. differs from A. atriventriS , A. buckleyi , A. copii , A. embera , A. feStae , A. lehmanni , and A. viridicepS (in parenthesis) in having scales on sides of neck similar in shape to dorsals, nongranular, keeled, imbricate (granular in A. atriventriS and A. buckleyi ; mostly granular in A. embera , A. feStae , A. lehmanni , and A. viridicepS ; conical with apparent bare skin between conical scales in A. copii ). It also differs from A. embera , A. feStae , and A. viridicepS in having gulars not in two longitudinal rows (vs. a double longitudinal row of widened gular scales); from A. lehmanni in having dorsal scales rhomboidal, in oblique rows (vs. dorsal scales hexagonal with parallel lateral edges, in transverse rows). AlopogloSSuS meloi sp. nov. differs from A. angulatuS (in parentheses) in having four pairs of chin shields (vs. three pairs), and third pair of chin shields irregularly trapezoidal, separated from gulars by large scales (vs. third pair of chin shields with rounded posterior margins, in direct contact with gulars or separated from them by a row of small, rounded or granular scales) ( Fig. 3 ).

Description of the holotype. Body cylindrical, rounded snout, neck almost as wide as head and anterior part of body, limbs well developed, tail longer than body ( Fig. 1 ). Measurements (mm): SVL = 57.5; AGL = 27.9; HD = 7; HW = 9.5; HL = 12.7; NL = 8.8; FL = 17.5; HLL = 33.2; ShL = 10.8; TL = 98 (1.69 times SVL).

Rostral hexagonal, in broad contact with frontonasal, but also contacting first supralabial and nasal. Viewed dorsally, the rostral is about three times as wide as high. Frontonasal pentagonal, wider than long (wider posteriorly), anteriorly in contact with rostral, laterally with nasal, and posteriorly with prefrontals. Prefrontals irregularly pentagonal, wider than long, with a short medial suture; laterally in contact with nasal, loreal, and first supraocular; posteriorly in contact with frontal. Frontal hexagonal, longer than wide (distinctly wider anteriorly), with lateral margins slightly concave; laterally in contact with first, second and third supraoculars; posteriorly in contact with frontoparietals. Frontoparietals irregularly pentagonal, longer than wide (wider posteriorly), with a wide medial suture; laterally in contact with third and fourth supraoculars; posteriorly in contact with interparietal and parietal. Interparietal pentagonal, lateral borders parallel to each other, about twice as long as wide. A pair of irregularly hexagonal parietals, wider than, and as long as, interparietal; laterally in contact with fourth supraocular, first and second supratemporals. Parietals and interparietal forming a slightly undulating (almost straight) posterior head margin. Occipitals absent. Four supraoculars, first smallest, contacting frontal, prefrontal, loreal, first superciliary, and second supraocular. Second supraocular largest, wider than long, contacting frontal, first and third supraoculars, and first and second superciliaries. Third supraocular slightly smaller than second, contacting frontoparietal, frontal, second and fourth supraoculars, and third superciliary. Fourth supraocular in contact with frontoparietal, third supraocular, third, fourth and fifth superciliaries, and first supratemporal. On the right side, a small triangular scale between second and third supraoculars, and second and third superciliaries. Five superciliaries, all elongated except fifth (irregularly triangular); first widest, contacting loreal, first and second supraoculars, and second superciliary; second in contact with first and third superciliaries, and second supraocular; third in contact with second and fourth superciliaries, and third and fourth supraoculars; fourth in contact with third and fifth superciliaries, and third and fourth supraoculars; fifth in contact with fourth superciliary, fourth supraocular, and first supratemporal. One small preocular between first superciliary, loreal, and frenocular. Three suboculars; first longer than wide, contacting frenocular, third supralabial, and second subocular; second similar in size with the first, contacting first and third suboculars, and third and fourth supralabials; third longer, about four times longer than wide, contacting second subocular, fourth, fifth and sixth supralabials, and the lower postocular. Two postoculars on the right side, and one on the left; lower postocular on the right side slightly larger than upper postocular; postocular on the left side longer, about four times longer than wide. Lower eyelid with semitransparent disc of four large palpebrals. Nasal semidivided, irregularly pentagonal, longer than wide. Nostril in the lower part of nasal, directed lateroposteriorly. Loreal rectangular, contacting nasal, prefrontal, first supraocular, first superciliary, and frenocular. Frenocular irregularly pentagonal, contacting loreal, nasal, second and third supralabials, and first subocular. Eight supralabials, fourth, fifth and sixth under the orbital region; sixth the tallest (dorsoventrally); first, fourth and fifth about twice as long as the others. One post-supralabial. Temporals irregularly polygonal, subimbricate, slightly keeled. Two large, slightly keeled supratemporal scales. Ear-opening vertically oval, with anterior margin denticulate. Tympanum recessed into a short auditory meatus. Except for supratemporals and temporals, all dorsal and lateral head scales smooth and juxtaposed.

Mental trapezoidal, about twice wider than long, with convex anterior margin. Postmental heptagonal, wider than long. Four pairs of chin shields; first pair as long as wide; second pair wider than long (wider posteriorly); third pair the largest, wider than long (wider anteriorly); fourth pair the smallest, wider than long. First two pairs of chin shields in broad contact medially and with first, second, third and fourth infralabials; third pair irregularly trapezoidal (heptagonal), in broad contact from each other medially and with fourth infralabial anteriorly, separated from gulars by large scales; fourth pair in contact from each other medially and with gulars posteriorly. One small granular scale between third and fourth pairs of chin shields, and one granular small scale between fourth pair of chin shields and gulars. Six infralabials, longer than wide; sixth the smallest; second, third, and fourth about twice as long as first; fourth the tallest (dorsoventrally); suture between third and fourth below centre of eye. One small post-infralabials. Gulars in eight transverse rows, smaller, but similar in shape to dorsals, pointed, imbricate, phylloid, except those forming first transverse row, which are smooth and have an almost rounded posterior margin; medial gulars smooth to feebly keeled; lateral gulars feebly keeled; gulars not differentiated in size toward collar. Posterior row (collar) with seven scales similar in size to preceding rows. No gular fold. Scales on nape similar in shape to dorsals; anteriormost nape scales smaller than dorsals. Three transverse rows of granular scales posteriorly to ear-opening. Scales on sides of neck distinctly smaller than dorsals, keeled, imbricate, phylloid; in seven transverse rows; anterior scales similar in shape to posterior ones but shorter. Area around shoulder with scales much smaller than, but similar in shape to neck scales.

Dorsal scales rhomboid, strongly keeled and mucronate, imbricate, and disposed in oblique rows; 24 scales along a middorsal line from parietals to the posterior level of hind limbs. Scales on flanks similar to dorsals. Twenty scales around midbody. Ventral scales feebly keeled, mucronate and imbricate, with posterior margin bluntly pointed; 15 transverse rows and four longitudinal rows between collar and preanals. Four smooth scales in preanal plate; two laterals distinctly smaller than, and separated by, medials; two medials irregularly hexagonals, preceded by four irregular scales. A continuous well separated series of femoral pores on each side; two pores on each side are in preanal position; total number of pores 23, ten on the right side and 13 on the left side; each pore between two scales.

Limb scales rhomboid, imbricate, sharply keeled, and mucronate dorsally; feebly keeled ventraly; tuberculate on ventral side of upper arms and posterior aspect of thighs. Five clawed digits on each of the four limbs. Lamellae under fingers single, transversely enlarged, and smooth; 15–16 under fourth fingers; lamellae under toes divided, 21 under fourth toe. Scales on tail keeled, slightly mucronate, imbricate; in transverse and in 12 longitudinal rows; proximally wider than long in the two paravertebral rows, longer than wide in other rows. Keels mostly sharp on tail (except on ventral rows where they are lower and broader), forming distinct longitudinal ridges (four dorsals, two laterals on each side, and four ventrals).

Dorsal surface of head, back, and tail light brown; head homogeneously light brown; from nape and along the middorsal, a median series of small dark brown spots, which merge between the hind limbs and the base of tail to form a dark brown band; posteriad this level, alternated dark brown and cream bands along the tail. A dashed, dark brown line extending posteriorly from the nostril to the tail dorsolaterally, passing through forelimbs dorsally, flanks dorsolaterally, and hind limbs dorsally (rather inconspicuous on flanks). A stripe slightly lighter than dorsal aspect of body bordering dorsolaterally the previous line from the posterior corner of eye to the tail. Lateral aspect of head and neck light brown, becoming gradually cream ventrally; a dashed cream line extending from the supralabials under the eye to the anterior surface of hind limbs, passing through the lower part of ear-opening and neck, forelimbs dorsally, and flanks ventrolaterally (rather inconspicuous on neck; bordered by a dashed darkbrown line on flanks). Flanks and lateral aspect of tail light brown (slightly darker than dorsal aspect of body), with some dark brown spots, becoming cream ventrally. Forelimbs light brown dorsally; hind limbs light brown with some small dark brown spots. Ventral aspect of body completely cream, with some small, irregular dark brown spots on preanal plate and tail.

Coloration in life (based on photographs of adult females). CZPB-RP 0 0 27 ( Fig. 4A ): Dorsal and lateral surfaces of head bright dark brown with blackish spots. Dorsal surface of body, limbs, and tail, dull dark brown with blackish spots; tail with alternated amber and blackish bands. A dorsolateral amber stripe from posterior corner of eye to anterior part of body. Neck slightly lighter than dorsal aspect of body, becoming gradually cream ventrally. Flanks, lateral surfaces of limbs and tail dull dark brown with blackish spots, becoming gradually cream ventrally on flanks and limbs. Iris vividly orange.

MHNCI 13588 ( Fig. 4B ): Dorsal surface of head bright amber with blackish spots; anterior surface of body bright orange, becoming gradually amber toward base of tail, with blackish spots. On the posterior dorsal surface of body, between the hind limbs and the base of tail, the dark spots merge to form a large blackish band. Dorsal surface of forelimbs orange; hind limbs amber. Dorsal surface of tail amber with orange and blackish spots. Lateral surface of head, neck, and anterior surface of flanks orange, becoming gradually amber posteriorly. Lateral surface of hind limbs and tail amber with small blackish spots. Iris vividly orange.

Variation. In MPEG 19880 there are five supraoculars. In MPEG 28271 there are seven superciliaries on one side and five on other. In MPEG 29381 there is a single elongated postocular on one side (twice as high) and two on other side; in MPEG 28271 and CZPB-RP 0 0 27 there are three postoculars on one side and two on other side. Post-supralabial usually absent, single if present. Third pair of chin shields in broad contact medially or separated from each other by 1–3 small granular scales. Fourth pair of chin shields in broad contact medially or separated from each other by 1–2 small granular scales; in direct contact with gulars or separated from them by a row of small scales. In MPEG 24373 there are nine gulars in transverse rows; in MHNCI 13588 there are seven. In CZPB- RP 0 0 27 ventral scales are smooth. Preanal and femoral pores are absent in females. In males, a continuous well separated series of femoral pores on each side; two pores on each side are in preanal position; total number of pores 20–23; each pore between two scales. In MPEG 19880 dorsal surface of tail is light brown with small irregular dark brown spots. In MPEG 19880, 24373, and 28271, the dashed cream line from the supralabials under the eye to the anterior surface of hind limbs is bordered on flanks by a dashed dark brown line. In females, the dashed cream line from the supralabials under the eye to the anterior surface of hind limbs is rather inconspicuous. In MPEG 24373 the ventral aspect of the tail and the preanal plate are completely cream. Table 1 present a summary of the variation in meristic characters and measurements, compared with its most similar species in morphology, AlopogloSSuS angulatuS .

Distribution and habitat. AlopogloSSuS meloi is distributed in the Southern Guiana Shield, northeastern Amazonia (north of the Amazon, east of Uatumã, and west of Paru rivers), in the states of Pará and Amazonas, endemic to Brazil ( Fig. 5 ). This region is encroaches into the Amazon Low Plateaus Sub-region (IBGE 1992; Salomão et al. 2012) characterized by the presence of many natural open vegetation enclaves (northern Amazonian savannas), which form with terra firme forest a mosaic of open and dense vegetation ( Ferraz 1993; Oliveira et al. 1999; Ribeiro-Júnior 2015a; Ribeiro-Júnior & Amaral 2016a, 2016b, 2017). Despite the presence of the savannas, the dense and dry (semideciduous) forests are predominantly found in the region ( Ávila-Pires et al. 2010; Aleixo et al. 2011).

The information available about the habitat of AlopogloSSuS meloi is quite poor and consists solely of museum data (except for CZPB-RP 0027; see below). The type series and referred specimens were encountered in the leaf litter, found predominantly in a more open, dry forest, compared with typical Amazonian dense forest. All specimens collected in the Trombetas–Nhamundá Interfluvium (west of Trombetas River, in the State of Pará; MPEG 15348, 16201, 19880, 24372–73, 28271) were found in plateaus; MPEG 19880 was collected in a reforestation area. Within this region there is significant mining of bauxite on plateaus, which influences the landscape and creates a mosaic of upland forest amid small and medium tributaries of the Trombetas River with heterogeneous reforestation and mining zones ( Ferraz 1993; Faria & Alvin 2013). MPEG 29381 and CZPB-RP 0 0 27 were collected in the Nhamundá–Uatumã Interfluvium (west of Trombetas River, in the State of Amazonas); MPEG 29381 in a forested area between two large patches of savannas, not interconnected; CZPB-RP 0 0 27 in a highly dissected terra firme terrain, in a region with also seasonally inundated meadows and patches of dense campina forest (see Oliveira et al. 2014). All other specimens were collected in the Trombetas–Paru Interfluvium (east of Trombetas River); MZUSP 53791–94, 54357–54358 were collected in a low, open forest, in an area under influence of fluvial regime of Erepecu Lake; MZUSP 78 122, 78207–08 were collected in a dry forest surrounded by patches of savanna and deforested areas. MHNCI 13588 and 13950 were collected in lowland dense forest, near water.

Etymology. The specific epithet is a noun in the genitive case honoring André Renato de Melo Teixeira, for his great contribution motivating and supporting the present study. I have a special debt of gratitude for his help, tenderness, and encouragement.

Figures

FIGURE 1. Dorsal (A) and ventral (B) views of the holotype of Alopoglossus meloi sp. nov. (MPEG 24372). Bar represents 10 mm.

FIGURE 2. Dorsal (A), ventral (B), and lateral (C) views of the head and neck of the holotype of Alopoglossus meloi sp. nov. (MPEG 24372). Bar represents 10 mm.

FIGURE 3. Ventral view of the head of the holotype of Alopoglossus meloi sp. nov. (A) (MPEG 24372) and the neotype of Alopoglossus angulatus (B) (RMNH 15200), showing differences in number and shape of the chin shields.

FIGURE 4. Living specimens of Alopoglossus meloi: (A) CZPB-RP 0027, from São José do Jatobá Village, São Sebastião do Uatumã (1°55'53"S, 58°15'21"W), State of Amazonas, Brazil─photo Sérgio Marques Souza; (B) MHNCI 13588, from Saracá- Taquera National Forest, Oriximiná (1°44'11"S, 56°24'36"W), State of Pará, Brazil─photo Sérgio Augusto Abrahão Morato.

FIGURE 5. Distributional records of the examined species of Alopoglossus angulatus and A. meloi. Symbols with a central dot refer to type-localities. Green: Amazonia; dotted line: limits of the Guiana Shield based on Hammond (2005: 38, Fig. 2.8) and Kok et al. (2006: 56, Fig. 9).