Rondonops xanthomystax, Colli, Guarino R., Hoogmoed, Marinus S., Cannatella, David C., Cassimiro, José, Gomes, Jerriane Oliveira, Ghellere, José Mário, Sales Nunes, Pedro M., Pellegrino, Kátia C. M., Salerno, Patricia, Souza, Sergio Marques De & Rodrigues, Miguel Trefaut, 2015

Colli, Guarino R., Hoogmoed, Marinus S., Cannatella, David C., Cassimiro, José, Gomes, Jerriane Oliveira, Ghellere, José Mário, Sales Nunes, Pedro M., Pellegrino, Kátia C. M., Salerno, Patricia, Souza, Sergio Marques De & Rodrigues, Miguel Trefaut, 2015, Description and phylogenetic relationships of a new genus and two new species of lizards from Brazilian Amazonia, with nomenclatural comments on the taxonomy of Gymnophthalmidae (Reptilia: Squamata), Zootaxa 4000 (4), pp. 401-427 : 414-418

Rondonops xanthomystax , sp. nov.

( Figs. 7–8 )

Holotype. MZUSP 98085 (field number MTR 12977); adult female; from left bank of Rio Abacaxis, São Sebastião, Borba (4°18'32"S, 58°38'11"W), Amazonas, BRAZIL; leg. M. T. Rodrigues, J. Cassimiro, S. M. Souza and J. M. Ghellere, 12 January 2007.

Paratypes. BRAZIL: AMAZONAS: Nova Olinda do Norte: Igarapé-Açu, right bank of Rio Abacaxis (4°20'39"S, 583°8'06"W): MZUSP 99243, 6 January 2007; Borba: São Sebastião, left bank of Rio Abacaxis (4°18'32"S, 58°38'11"W): MZUSP 99244–99246, 99248, 12–25 January 2007; Borba: Palhalzinho, left bank of Rio Abacaxis (4°18'06"S, 58°38'01"W): MZUSP 99247, 25 January 2007. All by the same collectors as for the holotype. PAR: Itaituba (5°27'19.22"S, 57°4'14.09"): MPEG 31109, leg. Team UFPA /Herpetologia, 31 August 2013; Jacareacanga (6°06'2241"S 57°36'19.91"W): MPEG 31103, 31107, 31110, leg. Team UFPA /Herpetologia, 30 September 2012, 27 January and 24 August 2013; (5°27'15.84"S, 57°4'41.02"W): MPEG 31104, leg. Team UFPA /Herpetologia, 13 October 2013; (5°48'03.1"S 57°24'23.4"); MPEG 31105–06, leg. Team UFPA / Herpetologia, 8 October 2013; (5°44'18.7"S 57°21'18.8"W): MPEG 31108, leg. Team UFPA /Herpetologia, 11 January 2013.

Etymology. The specific epithet is a noun derived from xanthos (Latin transliteration of the Greek ξανθός: yellow) and mustax (Latin transliteration of the Greek Μύσταξ: upper lip or moustache) ( Liddell & Scott 1889). The name refers to the yellow (in life) upper lip of this species, which strongly differs from that of its congener, where it is strongly mottled with dark brown.

Diagnosis. Body robust; tail up to 2.7 times longer than body. Limbs pentadactyl, slender; first finger lacking claw. Ear openings and eyelids distinct. Frontonasal single; prefrontals, frontal, frontoparietals, parietals and interparietal present; parietals longer than wide. Collar fold absent. Three pairs of chin shields; third pair reduced. Three supraoculars, anteriormost smallest. Dorsals (including nuchals) in 26–30 rows; nuchals multistriate, wide, imbricate, disposed in two longitudinal and 5–8 transverse regular rows; posterior of forearm insertion becoming progressively narrower, mucronate, with broad and flat keels, and then lanceolate, strongly keeled, imbricate, and mucronate. Occipitals absent. Ventrals very wide, smooth, imbricate, in two regular longitudinal and 15–18 transverse rows, identical in size and shape to nuchals. Scales around midbody 25–28; subdigital lamellae of finger IV and toe IV, respectively 13–17 and 20–26. Males with a continuous series of 19–24 pores, with no gap between preanal and femoral pores; femoral and preanal pores absent in females. Rondonops xanthomystax differs from R. biscutatus by having two longitudinal rows of 5–8 multistriate nuchals (6–10, smooth); scales on sides of neck keeled (smooth); 13–17 and 20–26 infradigital lamellae under finger IV and toe IV, respectively (11–15 and 16– 20); relatively longer fingers and toes. In R. xanthomystax , a wide black stripe covers all of the lateral surface of the head above the upper part of supralabials and extends from nasal to the insertion of the forearm, where it merges with the flank colour; below the black stripe, a bright orange-yellow colour covers the larger part of supralabials, infralabials, and ventral parts of head and throat. In R. biscutatus , the lateral dark stripe is absent and supralabials are strongly mottled with dark brown.

Description of the holotype ( Fig. 7 ). Adult female, in good state of preservation. Snout-vent-length 67 mm; tail regenerated, total length 68 mm, length of intact portion 62 mm. Rostral broad, wider than high, contacting first supralabials, nasals and frontonasal. Frontonasal heptagonal, wider than long, contacting rostral, nasals, loreal, and prefrontals. Prefrontals slightly wider than long, in broad contact at midline and contacting frontonasal, loreal, first and second supraoculars and frontal. Frontal hexagonal, with posteriorly, slightly convergent lateral margins, longer than wide, slightly wider anteriorly; anteriorly indenting prefrontal and, posteriorly, frontoparietals. Frontoparietals pentagonal, as wide as prefrontals, in broad contact, strongly indented by interparietal, in contact with second and third supraoculars and parietals. Interparietal longer than wide, slightly longer than and as wide as frontal, as long as and narrower than parietals. Parietals heptagonal; bordered laterally by three enlarged temporals (the second being largest), anteriorly by third supraocular and frontoparietal, medially by interparietal, and posteriorly by first row of nuchals. Posterior margin of parietals and interparietal rounded, contacting first row of nuchals. Three supraoculars; first smallest; second largest, forming a large suture with frontal, narrowly contacting frontoparietal and prefrontal; third supraocular larger than frontoparietals, in broad contact with frontoparietal, parietal and temporal. Nasal dorsal to first supralabial, large, slightly longer than high; nostril in middle of lower part of nasal, indenting suture with first labial. Loreal posterior to nasal, narrower and diagonally oriented; contacting nasal, frontonasal, prefrontal, first supraocular, first superciliary, preocular, frenocular, and first supralabial and second supralabials. Frenocular small, ventral to preocular, followed posteriorly by six suboculars, mostly elongate and about the same size; sixth subocular longest, almost square, followed by postocular. Seven supralabials; fourth below center of eye; fifth largest, contacting posterior suboculars; seventh supralabial smallest, contacting granules surrounding anterior margin of ear. Three superciliaries on right, four on left; first longest (right), deeper anteriorly, longer than first supraocular, contacting first and second supraoculars, loreal, preocular, second superciliary and upper eyelid; second superciliary smallest, contacting second supraocular (left) or second and third supraoculars (right). Enlarged quadrangular scale follows third superciliary and contacts postocular. Central part of lower eyelid with semitransparent, undivided disc surrounded by small, slightly pigmented, granular, smooth scales and twelve strongly pigmented palpebrals. Temporals smooth, juxtaposed, irregular in size and shape, largest temporal closer to ear and about the same size of sixth supralabial. Ear opening surrounded by series of very small, juxtaposed, rounded tuberculate granules; external auditory meatus shallow; tympanum distinct, subovoid. Scales on sides of neck in about 13 irregularly transverse series between ear and arm level; those next to ear small, smooth, rhomboid, almost juxtaposed, becoming gradually larger, more elongate, mucronate, keeled and imbricate near arm. Neck scales close to nuchals sharply keeled. All head scales smooth and juxtaposed, with many scattered sensorial pits.

Mental broad, wider than long. Postmental heptagonal, wider than long, contacting first and second infralabials. Three pairs of enlarged chinshields, in broad contact along midline; first smaller than second, contacting second and third infralabials on right side; second chinshield largest, contacting third and fourth infralabials on right side; third pair reduced, small, narrow, chevron-like, laterally contacting a scale that is slightly longer than wide; third pair of chinshields slightly smaller than fifth supralabial, separated from fifth infralabial by elongate scale. Six infralabials; first and second fused on left side; on the right, third and fourth infralabials largest, about the same size. Gulars enlarged, wider than long, smooth, imbricate, rounded posteriorly, in two longitudinal and seven transverse rows; scales in first row smaller. Interbrachial region distinct, with seven smooth, strongly imbricate scales; central one subtriangular, laterally contacting larger scales; external interbrachials smaller, longer than wide. Collar fold absent.

Nuchals large, wider than long, multistriate, imbricate, rounded posteriorly, in two identical longitudinal and six regular transverse rows between parietal area and just before insertion of the arm. Occipitals absent. Dorsals becoming progressively narrower, imbricate, mucronate, lanceolate, with strong central keel and several lateral striae, variable in position, just anterior to insertion of arm, continuing in this fashion to hind limbs; keels appearing gradually, broad and flat anteriorly, becoming thin, high and sharp posteriorly. Twenty-eight transverse rows of dorsals between parietals/interparietal and posterior level of hind limbs; six anterior rows corresponding to striate, enlarged series. Scales on flanks strongly keeled, mucronate and imbricate, slightly smaller, and more diagonally disposed than dorsals; flank scales from the row bordering ventrals smooth, wider, more imbricate and posteriorly rounded. Axilla with distinctive area with small, smooth and rounded granules. Twenty-five scales around midbody. Ventrals smooth, imbricate, wider than long, rounded posteriorly, in two longitudinal and 16 transverse rows from interbrachials (not included) to preanals. Five preanal scales; central scale rhomboidal (posterior part wider), not reaching preanal border, the latter being formed by two enlarged scales in broad median contact and two smaller external paramedials. Preanal and femoral pores absent. Caudal scales elongate, lanceolate, keeled, strongly imbricate, smaller than midbody dorsals; smaller on regenerated part of tail.

Forelimbs with large, smooth, imbricate scales, except on ventral part of forearm where they are much smaller, rounded, slightly imbricate, and on ventral part of upper arm where they are smaller than scales on corresponding dorsal parts. Anterior and ventral parts of hind limbs with irregularly large, smooth, imbricate scales, identical to those on corresponding parts of forelimbs, except for some on posterior dorsal part that are keeled. Scales on posterior part of hind limbs granular, juxtaposed, becoming larger, imbricate and keeled on dorsal part of tibia and femur. Carpal and tarsal scales large, imbricate, smooth; supradigital lamellae smooth, imbricate. Palmar and plantar surfaces with smooth, small, tuberculate granules. Fingers and toes relatively long and slender. Proximal and middle part of finger IV cylindrical, distal part laterally compressed. Proximal two-thirds of the 17 subdigital lamellae of finger IV single, flat to slightly bulbous, broad; distal scales single and smooth; divided lamella rarely present. Toe IV laterally compressed over its entire length; 23 subdigital lamellae single, narrow, with blunt ventral keel, or proximally a pointed tubercle on each lamella; middle part of finger with irregularly divided, paired scales, the distal scales being single. Toes and fingers clawed, except finger I; relative sizes: 1 <2 = 5 <3 = 4 and 1<2 <5 <3 <4, respectively.

Dorsal surfaces of body, flanks and tail dark brown; dorsal part of head paler, olive-brown with scattered dark brown punctuate spots ( Fig. 8 ). Lateral parts of head with a wide black stripe covering the entire lateral surface above the upper part of supralabials and extending from the nasal to arm level, merging there with flank colour. Below it, a bright orange-yellow bright colour covering most parts of supralabials, infralabials and ventral parts of head and neck. Ventral parts of body cream-yellow, strongly mottled, with irregular black pigmentation concentrated in anterior and central part of scales. Ventral parts of tail dark brown near its tip. Tail dark brown dorsally, slightly lighter ventrally. Limbs dark brown dorsally, irregularly mottled with cream-yellow; ventrally, cream-yellow, immaculate.

Variation and sexual dimorphism. Variation in morphology is summarized in Table 1. The holotype (67 mm) is the largest specimen in the type series. The sexes can be readily separated by the absence of preanal and femoral pores in females. In addition, females have higher numbers of ventrals than males ( Table 1, t = 3.025, df = 11.816, P = 0.011).

deviation and range (in parentheses). Tail length statistics refer to intact tails only.

Variables Rondonops biscutatus Rondonops xanthomystax

Females (24) Males (36) Total (60) Females (10) Males (5) Total (15)

Snout-vent length (mm) 50.46 ± 8.06 53.94 ± 8.04 52.55 ± 8.16 54.8 ± 13.23 52.8 ± 16.33 54.13 ± 13.77 (26–61) (28–66) (26–66) (27–67) (30–66) (27–67)

Tail length (mm) 101.56 ± 28.67 125.6 ± 41.79 110.14 ± 34.44 127.40 ± 48.67 114.33 ± 53.2 122.5 ± 46.99 (47–140) (68–170) (47–170) (52–165) (64–170) (52–170)

Dorsals (incl. nuchals) 30.29 ± 1.27 29.14 ± 1.29 29.60 ±.39 28.50 ± 0.97 27.40 ± 1.14 28.13 ± 1.13 (27–32) (26–31) (26–32) (27–30) (26–29) (26–30)

Nuchals in double row 8.29 ± 0.75 8.06 ± 1.09 8.15 ± 0.97 6.10 ± 0.74 7.00 ± 0.71 6.40 ± 0.83

(7–9) (6–10) (6–10) (5–7) (6–8) (5–8)

Fourth finger lamellae 13.00 ± 1.00 12.92 ± 1.05 12.95 ± 1.02 16.33 ± 0.71 15.40 ± 1.52 16.00 ± 1.11 (11–15) (11–15) (11–15) (15–17) (13–17) (13–17)

Fourth toe lamellae 18.13 ± 1.01 17.61 ± 0.80 17.81 ± 0.92 22.67 ± 1.50 21.40 ± 1.34 22.21 ± 1.53 (16–20) (16–19) (16–20) (21–26) (20–23) (20–26)

Gulars 6.71±0.46 6.72 ± 0.51 6.72 ± 0.49 6.90 ± 0.32 6.80 ± 0.45 6.87 ± 0.35

(6–7) (6–8) (6–8) (6–7) (6–7) (6–7)

Infralabials 6.33±0.48 6.5 ± 0.51 6.43 ± 0.50 6.30 ± 1.06 6.80 ± 0.45 6.47 ± 0.92

(6–7) (6–7) (6–7) (4–8) (6–7) (4–8)

Pores — 19.81 ± 1.28 — — 22.2 ± 2.05 —

— (17–22) — — (19–24) —

Scales around midbody 25.29 ± 0.81 26.14 ± 1.29 25.80 ± 1.19 26.11 ± 1.05 26.00 ± 1.00 26.07 ± 1.00 (24–26) (23–30) (23–30) (25–28) (25–27) (25–28)

Suboculars 4.79±0.41 4.86 ± 0.64 4.83 ± 0.56 5.30 ± 0.48 5.00 ± 0.00 5.20 ± 0.41

(4–5) (3–7) (3–7) (5–6) (5–5) (5–6)

Superciliaries 3.00±0.00 2.97 ± 0.17 2.98 ± 0.13 3.10 ± 0.32 3.20 ± 0.45 3.13 ± 0.35

(3–3) (2–3) (2–3) (3–4) (3–4) (3–4)

Supralabials 6.96±0.46 7.00 ± 0.24 6.98 ± 0.34 6.70 ± 0.48 7.00 ± 1.22 6.80 ± 0.77

(6–8) (6–8) (6–8) (6–7) (5–8) (5–8)

Supraoculars 3.00±0.00 3.00 ± 0.00 3.00 ± 0.00 3.00 ± 0.00 3.00 ± 0 3.00 ± 0.00

(3–3) (3–3) (3–3) (3–3) (3–3) (3–3)

Ventrals 18.12 ± 1.65 16.28 ± 1.28 17.02 ± 1.69 16.56 ± 0.88 15.40 ± 0.55 16.14 ± 0.95 (15–20) (14–18) (14–20) (15–18) (15–16) (15–18) Distribution, habitat and natural history. Rondonops xanthomystax is known from the forests of the middle Rio Abacaxis, Amazonas, and of the upper Rio Tapajós, in southwestern Pará, Brazil ( Fig. 6 ). Seven specimens were obtained in two adjacent municipalities: Borba and Nova Olinda do Norte, on opposite sides of the Rio Abacaxis, Amazonas. All specimens were collected in primary terra firme forest, characterized by open understory, high abundance of palm trees, dense leaf litter and frequent large trees with more than 80 cm diameter and up to 40 m, like the Brazil nut Bertholletia excelsa ( Fig. 8 ). One adult and two juveniles were collected by hand around 11:00 AM when foraging in sunny spots among the leaf litter. Three were taken from pitfall traps ( Fig. 8 ) consisting of a set of four 30-liter buckets, arranged in a Y, separated by 4 m long drift fences, for a total effort of 175 traps x day. One specimen was collected on a small glue trap about 1.7 m high on the trunk of a diagonallyoriented fallen tree, approximately 50 cm in diameter. Six specimens from Rio Tapajós were collected in pitfall traps in terra firme forest, but MPEG 31107 and 31110 (both from Jacareacanga) were collected in riparian areas. Of the 10 females collected two were gravid, the holotype (MZUSP 98085) and MPEG 31106, each with one egg.

Figures

FIGURE 6. Geographic distribution of Rondonops biscutatus (triangles) and R. xanthomystax (circles). 1,2: Borba and Nova Olinda do Norte, 3: Novo Progresso, 4: Alta Floresta, 5: Guajará-Mirim, 6: Pimenta Bueno, 7: Alta Floresta d'Oeste, 8: Cerejeiras, 9: Itaituba, 10: Jacareacanga. AM: Amazonas, MT: Mato Grosso, PA: Pará, RO: Rondônia.

FIGURE 7. Rondonops xanthomystax, holotype, MZUSP 98085, adult female, SVL 67 mm. (A) Lateral view of head; (B) ventral view of the head; (C) dorsal view of the head.

FIGURE 8. (A) View of a flooded forest near Igarapé-Açu, right bank of Rio Abacaxis, Nova Olinda do Norte, Amazonas Brazil; (B) terra firme forest at Igarapé-Açu; (C) holotype of Rondonops xanthomystax in life. (D) Closer view of the same specimen.