Tropidurus lagunablanca, André Luiz G. Carvalho, 2016

André Luiz G. Carvalho, 2016, Three new species of the Tropidurus spinulosus group (Squamata: Tropiduridae) from Eastern Paraguay, American Museum Novitates 3853, pp. 1-44 : 7-15

Tropidurus lagunablanca , n. sp.

Figures 2 A–F, 3A–F

Holotype: CZPLT-H 402 (adult male; 23° 48 ′ 43.20 ″ S 56° 17 ′ 40.92 ″ W, WGS84 system; ~207 m above sea level; geographic coordinates not specified in the CZPLT catalog, estimated based on field observations of the restricted local distribution of the species in the type locality in September 2013), collected at Reserva Natural Laguna Blanca, Santa Rosa del Aguaray, San Pedro, Paraguay.

Paratypes: AMNH-R 176291 (juvenile male), AMNH-R 176292 (adult female), collected at Reserva Natural Laguna Blanca, Santa Rosa del Aguaray, San Pedro, Paraguay (23° 48 ′ 43.20 ″ S 56° 17 ′ 40.92 ″ W, WGS84 system; ~207 m above sea level) by André L. Gomes de Carvalho, Frederick Bauer, Nicolás Martínez, Viviana Espínola, and Marcelo Dujak in 7 September 2013. AMNH-R 176293 (adult female), collected at Reserva Natural Laguna Blanca, Santa Rosa del Aguaray, San Pedro, Paraguay (23° 48 ′ 43.20 ″ S 56° 17 ′ 40.92 ″ W, WGS84 system; ~207 m above sea level) by André L. Gomes de Carvalho, Rodrigo Ayala, and Johanna López in 29 September 2013. CZPLT-H 157, CZPLT-H 406, CZPLT-H 409, CZPLT-H 461 (adult males), CZPLT-H 405 (juvenile male), collected at Reserva Natural Laguna Blanca, Santa Rosa del Aguaray, San Pedro, Paraguay. MNHNP 11463 (adult male), collected at Laguna Blanca, San Pedro, Paraguay, by Norman J. Scott in 18 February 2010. MNHNP 11755 (juvenile male), MNHNP 11756 (subadult male), collected at Reserva Natural Laguna Blanca, Santa Rosa del Aguaray, San Pedro, Paraguay (23° 48 ′ 43.20 ″ S 56° 17 ′ 40.92 ″ W, WGS84 system; ~207 m above sea level), by André L. Gomes de Carvalho, Rodrigo Ayala, and Johanna López in 29 September 2013.

Morphological diagnosis: Tropidurus lagunablanca , n. sp., may be distinguished from all congeners by the following combination of characteristics: (1) adult large and robust, reaching 113.09 and 94.59 mm SVL in males and females, respectively; (2) iris golden brown; (3) strongly projecting, serrate vertebral crest in males, reduced in females; (4) 1–2 canthals; (5) preocular not contacting canthal; (6) two rows of circumorbitals; (7) moderate tufts of neck spines; (8) high number of scales around midbody (100–113 in males and 107–114 in females); (9) sexes not extraordinarily dimorphic in body proportions, scutellation, and color pattern; (10) bright yellow lips in males; (11) orange coloration on the neck, posterior and lateral head (small greenish-blue spots, usually 2–3 scales in size, distributed frontally), extending posteriorly to form a vertebral stripe in males; (12) dorsum and flanks with gray background decorated with numerous greenish-blue light specks one scale in size or smaller, and irregular dark spots; (13) venter of head with dark and/or burnt orange spots, never exhibiting dark bars on the chin connected with a dark medial patch; (14) creamy yellow flash marks on the underside of the thighs and precloacal flap; (15) arboreal habits.

Comparison with Other Species: Tropidurus lagunablanca , n. sp., is likely to be confounded with T. tarara , n. sp., but differs from that species by having males with orange coloration on the neck and posteriormost and lateral parts of the head, and greenish-blue spots 1–3 scales in size decorating the head frontally; the orange coloration of the neck extends posteriorly forming a vertebral stripe composed of circular blotches of variable sizes somewhat similar to, but not as circular as the ones on the head (males of T. tarara , n. sp., exhibit orange coloration as blotches or spots over the whole head and neck, and orange vertebral stripe formed by circular or irregular blotches of variable sizes). In both species, a dark, reticulated pattern is found on the head and neck, delimiting individual orange or orangey cream circular blotches (and greenish-blue spots in the frontal head of males of T. lagunablanca , n. sp.). Females of T. lagunablanca , n. sp., have higher number of ventrals (88–89 in T. lagunablanca , n. sp.; 77–82 in T. tarara , n. sp.), gulars (73–77 in T. lagunablanca , n. sp.; 59–69 in T. tarara , n. sp.), scales around midbody (107–114 in T. lagunablanca , n. sp.; 95–104 in T. tarara , n. sp.), lamellae under fourth finger (20–21 in T. lagunablanca , n. sp.; 16–19 in T. tarara , n. sp.), and lamellae of four toe (26–27 in T. lagunablanca , n. sp.; 21–25 in T. tarara , n. sp.).

Tropidurus lagunablanca , n. sp., differs from T. teyumirim , n. sp., by having larger body size (89.35–113.09 mm SVL in males and 75.48–94.59 mm SVL in females of T. lagunablanca , n. sp.; 67.82–94.41 mm SVL in males and 61.41–80.79 mm SVL in females of T. teyumirim , n. sp.) and cream or creamy yellow flash marks on the underside of the thighs and precloacal flap (orange-yellow in T. teyumirim , n. sp.). Tropidurus lagunablanca , n. sp., may still be distinguished from T. guarani and T. teyumirim , n. sp., by having males with a strongly projecting, serrate vertebral crest (low in the latter forms) and bright yellow lips (lips not as intensely colored in yellow and presenting stronger black bars in the later forms), orange coloration of the neck extending posteriorly to form a well-marked vertebral stripe, and venter of head decorated with tiny dark and/or burnt orange spots (vertebral stripe absent or lightly pigmented in orange, and chin decorated with intense black bars oriented lateromedially, connecting with a dark medial patch posteriorly in the latter forms).

Tropidurus lagunablanca , n. sp., could be confused with T. xanthochilus both of which have intense yellow lips and a strongly projecting, serrate dorsal crest. However, the new species differs from the latter form by having much lower number vertebrals (56–64 in males and 67–87 in females of T. lagunablanca , n. sp.; 80–87 in males and 105–118 in females of T. xanthochilus ), cream or creamy yellow flash marks on the underside of the thighs and precloacal flap (orange-yellow in T. xanthochilus ), and iris golden brown (dark in T. xanthochilus ).

Tropidurus lagunablanca , n. sp., is distinguished from T. spinulosus by presenting moderate tufts of spines laterally on neck (strongly projecting in T. spinulosus ), dorsal background and flanks gray, scattered with greenish-blue light specks restricted to one scale or smaller (greenishblue light specks absent in T. spinulosus ), and higher number of scales around midbody (100–113 in males and 107–114 in females of T. lagunablanca , n. sp.; 77–98 in males and 82–95 in females of T. spinulosus ). Tropidurus lagunablanca , n. sp., may be easily differentiated from T. callathelys and T. melanopleurus by presence of a gray background and lacking pronounced sexual dimorphism and dichromatism (males of T. callathelys are dark olive and females have a dark dorsal background and a flame scarlet head; males of T. melanopleurus have an intense orange head and complex dorsal coloration, with marked black background with light blotches anteriorly, transitioning into gray background with vivid green-yellow spots. Females have a brown head, black dorsal background laterally decorated with 4–6 red, cream, and green bands). Tropidurus lagunablanca , n. sp., is also distinguishable from T. callathelys and T. melanopleurus by having males with extremely serrate black and white vertebral crest, with touches of greenish blue (strongly serrate but very white, contrasting against the dark olive background in T. callathelys ; low and similar in color to background in T. melanopleurus ). The new species may also be differentiated by having two rows of circumorbital scales (one in T. callathelys and T. melanopleurus ) and by lacking contact between preocular and canthal (preocular and posteriormost canthal in contact in T. melanopleurus ). Unlike T. callathelys , T. guarani , T. melanopleurus , and T. teyumirim , n. sp., T. lagunablanca , n. sp., is arboreal (the former species are saxicolous).

Description of holotype: Large species of Tropidurus , body and limbs robust, SVL 109.33 mm; head triangular, length 27% of SVL and width 71% of head length; skull slightly depressed medially, not particularly elevated at level of the orbits; rostrum not shortened relative to most other species of the T. spinulosus group; scales of frontonasal region slightly elevated, not imbricating posteriorly; one to several diminutive scale organs present on head scales; rostral not tall, about 2 times as high as first supralabial, not tumescent, contacting first supralabials, first lorilabials, and three postrostrals; 2/1 postrostrals; nasal single, slightly higher than adjacent scales, separated from rostral by postrostral-lorilabial contact; 6/6 enlarged supralabials followed by a series of smaller scales that reach the rictus oris, never contacting subocular; nostril elliptical, occupying about 45% of nasal, positioned posteriorly, directed dorsolaterally; 2/2 canthals, anteriormost canthal separated from supralabials by 1/1 rows of loreals and 2/2 rows lorilabials; 6/6 enlarged, imbricate, diagonally oriented, laminate superciliary scales; 1/1 dorsally keeled, subretangular preoculars contacting 4/5 loreals; 1/1 dorsally keeled, elongate suboculars; palpebrals granular, second row with scales tumescent, subconical, bearing a scale organ on top; 2/2 main rows of supraoculars, the largest ones several times larger than the smallest; posteriormost enlarged supraoculars occupying whole width of the supraocular area; 2/2 rows of small, angulate circumorbitals, similar in size or slightly larger than the smallest supraocular scales; 1/1 rows of semilaminate scales separating supraorbitals and superciliaries; 1/1 rows of short, laminate scales separating superciliaries and palpebrals; interparietal enlarged, subcordiform, 14% wider than long; parietal eye visible, positioned medially on the posterior limit of the first third of the interparietal scale; temporals unkeeled, angulate, tumescent, slightly imbricate posteriorly, noticeably larger than lateral neck scales and smaller than parietals, upper temporals slightly larger than lower temporals; one row of occipitals separating interparietal from dorsals; ear opening shaped like inverted keyhole, canal deep, largest diameter of meatus about 25% of meatus to snout distance; tympanum semitranslucent; preauricular fringe with a lower cluster of 5/5 spines; width of mental about 70% of the width of rostral; mental extending posteriorly to the level of two thirds of the adjacent infralabials; 6/6 enlarged infralabials followed by a series of small scales that reach the rictus oris; 3/3 enlarged postmentals; 1/1 postmentals in contact with first infralabial; first postmentals in contact with one another; 6/7 sublabials in contact with enlarged infralabials; 80 gulars, imbricated posteriorly; 3/3 nearly aligned and evenly spaced tufts of keeled, mucronate spines located between the dorsal margin of the ear and dorsal limit of the oblique neck fold, largest spines up to eight times larger than lateral neck spines; additional smaller clusters of heavily mucronate scales present on the lateral neck.

Vertebral crest present, extremely serrate, extending to the end of the first half of tail (tail regrown), vertebral spines much larger anteriorly, before nuchal collar, reaching twice the size of the posterior ones; 57 vertebrals; 120 paravertebrals; 100 scale rows around midbody; 86 ventrals; dorsals large, moderately keeled, imbricate, mucronate, up to about 20% larger than scales on the flanks; small, nonmucronate scales in the axillary region, growing in size and mucronation along the flanks; ventrals smooth, nonmucronate, imbricate, smaller than dorsals; flash marks on the underside of the thighs formed by 7/7 rows of glandular scales; 19 cloacal scales, precloacal flap with 8 rows of glandular scales similar to the ones on the underside of the thighs; supracarpals and supratarsals subtriangular, smooth or keeled, bearing a scale organ on the distal end of the scale; infracarpal and infratarsal scales smooth, slightly mucronate; digits thin, cylindrical, slightly compressed laterally; supradigital lamellae smooth, subtriangular to subrhomboidal, scale organ positioned on the distal end of the scales; infradigital lamellae tricarinate, 21/20 under fourth finger, 26/27 under fourth toe, medial keel larger and more projected than lateral; ungual similar to subdigital lamellae, nearly smooth; claws long, curved; pre- and postaxial scales of brachium moderately keeled or nearly smooth, slightly mucronate or presenting a scale organ on the distal end; preaxial thigh scales moderately keeled or smooth, slightly mucronate, postaxial ones heavily keeled and mucronate; 26/26 crus scales, keeled, mucronate; rictal fold present; nuchal and suprauricular folds absent; postauricular and longitudinal neck folds present, antegular fold heavily marked, bearing a deep mite pocket ventrolaterally, coated with diminutive granular scales; supernumerary antegular fold present; oblique neck fold well marked; gular fold incomplete medially, extending dorsally to form a heavily marked antehumeral fold; axillary and inguinal mite pockets absent; tail cylindrical, slightly compressed; caudal verticils absent; scales of tail keeled, mucronate, imbricate, up to three times larger than dorsals, caudal crest formed by serrate, laterally deflected, expanded scales.

Coloration in life: There are no notes of coloration in life of the holotype.

Coloration in preservative: Coloration of the head, neck, and vertebral area pale orangish cream or cream; light areas in these regions contoured with dark, reticulated pigmentation defining circular blotches and spots of variable sizes; lateral head and neck with coloration similar to dorsal head, but decorated with moderately larger circular light blotches. Coloration of the head and neck extends posteriorly to form a well-defined vertebral stripe composed of continuous light blotches of variable sizes present middorsally. Lips pale cream, bearing four complete or interrupted dark bars extending downwards. Ventral side of head pale cream, with faded, coarsely defined, dark-pigmented bars marginally on chin. Dorsal background dark gray, decorated with numerous light, greenish-blue speckles one scale in size or smaller, and dark blotches and spots of variable sizes. Four evenly spaced pairs of irregular, interrupted dark bars on dorsum (the anterior one rhombic in shape), with lateral tips extending towards the upper flanks. Flanks background gray, similar to dorsum, slightly lighter, decorated with numerous light, greenish-blue speckles one scale in size or smaller, and multiple small dark spots; dark spots on flanks slightly smaller than dorsolateral ones, occasionally forming an anastomosed pattern. Dark nuchal collar incomplete dorsally and U-shaped dark mark located between the back of the head and nuchal collar, both well marked.

Ventral ground coloration cream; chest and area between gular and antegular folds pigmented in black; lateral limits of the venter contact a thin, bluish area along the lower flanks, between the axillary and inguinal regions. Fore- and hind limbs with coloration similar to flanks, grading into an orangey cream background towards the dorsum of manus and pes. Light, greenish-blue speckles and dark spots present on limbs; distal regions of forelimbs, manus, and pes with thin dark stripes, more evident on digits. Ventral surface of forelimbs, hind limbs, manus, and pes cream, similar to venter of body and tail. Femoral and precloacal glandular flash marks pale creamy yellow. Tail with coloration similar to dorsum, slightly lighter; posterior half of tail grading into dull orangish cream; small dark spots scattered dorsally and on upper flanks of tail forming an anastomosed pattern; lower limits and ventral surface of the tail cream.

Measurements of the holotype (in mm): SVL: 109.33: TL: 143.65; BH: 15.35; BW: 32.82; HH: 14.33; EOS: 24.95; HL: 30.13; HW: 21.70; AL: 17.30; FAL: 15.14; HDL: 20.97; THL: 21.74; SL: 19.79; FOL: 30.30; AGD: 46.31.

Etymology: The epithet lagunablanca , an indeclinable word, refers to the type locality of the new species, the Reserva Natural Laguna Blanca, located in Santa Rosa del Aguaray, Department of San Pedro, Paraguay.

Distribution, natural history, and conservation status: Tropidurus lagunablanca , n. sp., is currently known exclusively from the type locality, the Reserva Natural Laguna Blanca, Department of San Pedro, Paraguay (figs. 1, 3G). Inside the reserve, the local range of the new species is apparently restricted to an area no larger than ~120,000 m2. Tropidurus lagunablanca , n. sp., was sighted only on large trees around the main house of the biological station, and very few specimens were observed in natural patches of sandy Cerrado woodland on the northern section of Laguna Blanca (J.P. Brouard, personal commun.; fig. 3H). Large sandy Cerrado fragments and the semideciduous Atlantic Forest that once covered the surroundings of Laguna Blanca were mostly converted into agricultural zones, with the result that natural landscapes that presumably harbored larger populations of T. lagunablanca , n. sp., no longer exist. For that reason, I support its classification under the category “critically endangered” according to the rules proposed by IUCN (2001). Additional fieldwork is needed to allow for a proper assessment of the distribution range of T. lagunablanca , n. sp., and molecular studies focused on the identification of genetic bottlenecks and determination of population viability are highly advisable.

Tropidurus lagunablanca , n. sp., is an arboreal species, very similar in habit to T. tarara , n. sp., and T. spinulosus . Feeding strategies and dietary preferences of T. lagunablanca , n. sp., have not been studied, but individuals from the Reserva Natural Laguna Blanca have been observed feeding on termites and wasps from nests located on the trees used by the species. Some individuals were also sighted hunting insects on the ground by quickly running down the tree trunks and, in just a few seconds, returning to their original position on the trees after having succeeded in capturing insects on the ground. Tropidurus lagunablanca , n. sp., is heliophilous and the frequency of specimen encounters apparently depends on environmental temperature and amount of sunlight. On a overcast day of fieldwork during my second visit to the Reserva Natural Laguna Blanca, I observed a much reduced number of active specimens, and their positions on the trees seemed determined by the distribution of patches of sunlight. Detailed assessments of ecological parameters, distribution limits, and population size of T. lagunablanca , n. sp., have never been performed, and should be prioritized due its critically endangered conservation status.

Figures

FIGURE 2. Holotype of Tropidurus lagunablanca, n. sp. (CZPLT-H 402). A – C. Dorsal, lateral, and ventral views of the head. D – F. Dorsal, lateral, and ventral views of the body.