Homonota taragui, Cajade, Rodrigo, Etchepare, Eduardo Gabriel, Falcione, Camila, Barrasso, Diego Andrés & Alvarez, Blanca Beatriz, 2013
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publication ID |
https://doi.org/ 10.11646/zootaxa.3709.2.4 |
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publication LSID |
lsid:zoobank.org:pub:0066DBF2-80C4-4AF9-A0FE-7DD6D1E5097D |
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DOI |
https://doi.org/10.5281/zenodo.5691385 |
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persistent identifier |
https://treatment.plazi.org/id/03EA4155-5205-FF9E-FF39-062E3961AD4C |
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treatment provided by |
Plazi |
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scientific name |
Homonota taragui |
| status |
sp. nov. |
Homonota taragui sp. nov.
Figs. 2 View FIGURE 2 , 3 View FIGURE 3
Holotype. Fig. 2 View FIGURE 2 , 3 View FIGURE 3 UNNEC 11293, adult female from Paraje Tres Cerros, Cerro Nazareno (29º06'34,30"S, 56º55'51,92"W, 168 m a.s.l.), Estancia “La Higuera Cue”, General San Martín Department, Corrientes Province, Argentina, collected by R. Cajade, E.G. Etchepare, C. Falcione, and D.A. Barrasso on 21 November 2010.
Paratypes. All paratypes (21 specimens) from the same locality as the holotype, but collected in different hills and dates:
Cerro Nazareno (29º06'34.30"S, 56º55'51.92"W, 168 m a.s.l.), Estancia “La Higuera Cue”, collected by R. Cajade and E.G. Etchepare on 12 November 2010: UNNEC 11287 a juvenile, UNNEC 11289 a juvenile, UNNEC 11297 an adult female, MLP.S 5796 an adult female. Cerro Nazareno (29º06'34.30"S, 56º55'51.92"W, 168 m a.s.l.), Estancia “La Higuera Cue”, collected by R. Cajade, E.G. Etchepare, C. Falcione, and D.A. Barrasso on 21 November 2010: UNNEC 11281 an adult female, UNNEC 11283 an adult male, UNNEC 11285 an adult female.
Cerro Capará (29°06’45.68’’S, 56°55’13.10’’W, 143 m a.s.l.), Estancia “La Higuera Cue”, collected by R. Cajade, E.G. Etchepare, C. Falcione, and D.A. Barrasso on 21 November 2010: UNNEC 11277 an adult male, UNNEC 11278 an adult female, UNNEC 11279 an adult male, UNNEC 11282 an adult female, UNNEC 11284 an adult female, UNNEC 11288 a juvenile, UNNEC 11291 a juvenile, UNNEC 11292 a juvenile, UNNEC 11303 a juvenile, UNNEC 11304 a juvenile, MLP.S 5797 a juvenile.
Cerro El Chico (29°09’14.30’’S, 56°55’09.80’’W, 140 m a.s.l.), Estancia “Las Marías”, collected by R. Cajade, E.G. Etchepare, and C. Falcione on 6 May 2011: UNNEC 11294 an adult female, UNNEC 11295 an adult female, UNNEC 11296 an adult male.
Diagnosis.— Homonota taragui is a small species of Homonota (SVL= 41.86 mm; Table 1 View TABLE 1 ) that can be distinguished from other species of the genus by the following set of characters: a well-marked dorsal, reticulate, dark pattern contrasting with the lighter colored background; small, star-shaped chromatophores on the abdomen; presence of an internasal scale contacting the rostral scales; granular scales covering the post-orbital region of the head; granular scales forming smooth edges of the meatus auditory; presence of moderately keeled scales on the dorsal and lateral surface of the body; keeled scales contiguously disposed on the dorsal surface of the body; cycloid scales covering the dorsal surface of the arms; moderately keeled scales interspersed with cycloid scales covering the dorsal and anterior regions of the thighs.
Homonota taragui differs from H. andicola in the following characters: presence of keeled scales on the dorsal and lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. andicola ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. andicola ). Homonota taragui differs from H. borellii in the following characters: presence of keeled scales on the lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. borellii , Fig. 4 View FIGURE 4 ); presence of an internasal scale contacting the rostral scales (internasal scales absent in H. borellii , Fig 5 View FIGURE 5 ). Homonota taragui differs from H. darwinii in the following characters: keeled scales extended along the whole dorsal body surface (keeled scales only on the posterior half of the dorsal body surface in H. darwinii ); presence of keeled scales on the lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. darwinii ); subcaudal scales transversely rectangular (vertically rhomboid in H. darwinii , Fig 6 View FIGURE 6 ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. darwinii ). Homonota taragui differs from H. fasciata in the following characters: rows of keeled scales on dorsal surface of the body composed by moderately keeled scales disposed contiguously (composed by strongly keeled scales separated from each other in H. fasciata ); dorsal surface of the arms covered by cycloid scales (covered by keeled scales in H. fasciata ); presence of an internasal scale contacting the rostral scales (internasal scale absent in H. fasciata , Fig. 5 View FIGURE 5 ); subcaudal scales transversely rectangular (rhomboid vertically and transversely rounded in H. fasciata , Fig. 6 View FIGURE 6 ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. fasciata ). Homonota taragui differs from H. rupicola in the following characters: presence of keeled scales on the lateral surface of the body and dorsal surface thighs (keeled scales absent in H. rupicola , Fig. 4 View FIGURE 4 ); presence of an internasal scale contacting the rostral scales (internasal scale absent in H. rupicola , Fig. 5 View FIGURE 5 ). Homonota taragui differs from H. underwoodi in the following characters: presence of chromatophores on the abdomen (chromatophores on abdomen absent in H. underwoodi ); presence of keeled scales on the dorsal and lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. underwoodi ); presence of an internasal scale contacting the rostral scales (internasal scales absent in H. underwoodi , Fig. 5 View FIGURE 5 ); subcaudal scales transversely rectangular (vertically rhomboid in H. underwoodi ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. underwoodi ). Homonota taragui differs from H. uruguayensis in the following characters: rows of moderately keeled juxtaposed scales on the dorsal surface of the body (strongly keeled imbricate scales in H. uruguayensis ); dorsal surface of the arms covered by cycloid scales (covered by keeled scales in H. uruguayensis ); the post-orbital region of the head covered only with granular scales (covered with granular scales interspersed with large keeled scales in H. uruguayensis , Fig. 7 View FIGURE 7 ). Homonota taragui differs from H. whitii in the following characters: presence of keeled scales on the dorsal and lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. whitii ); presence of an internasal scale contacting the rostral scales (internasal scale absent in H. whitii , Fig. 5 View FIGURE 5 ); subcaudal scales transversely rectangular (rounded and longitudinally elongated in H. whitii , Fig. 6 View FIGURE 6 ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. whitii ). Homonota taragui differs from H. williamsii in the following characters: presence of keeled scales on the lateral surface of the body and dorsal surface of the thighs (keeled scales absent in H. williamsii ); subcaudal scales transversely rectangular (longitudinally elongated in H. williamsii , Fig. 6 View FIGURE 6 ); the auditory meatus with smooth edges formed by granular scales (serrated edges formed by conical scales in H. williamsii ).
Description of holotype.—Body short, 3.9 times as long as the head. Head subtriangular, slightly widened, snout rounded, and neck moderately defined. Eyes diameter 4.1 times smaller than head length, and the pupil vertical with irregular edges. Measurements: SVL = 41.3 mm; TL = 53.8 mm; HL = 10.3 mm; HW = 8.5 mm; ED = 2.5 mm; EOD = 0.7 mm; END = 2.9 mm; EEOD = 3.6 mm; VW = 4.3 mm. Dorsal surface of the head covered by granular scales, with notably larger scales between the eyes and snout. Rostral scales pentagonal, wider than high, with two oblique grooves extending from the nostrils to the central region of the scale where end. Seven supralabial scales and five infralabial scales present on each side of the upper and lower jaws, respectively. One internasal scale in contact with the rostral scales. Nostril bordered by the first supralabial, rostral, supranasal and two postnasal scales. Thirty supraciliary scales forming a ruffle orbit edge. Auditory meatus small, elliptical, and oblique with respect to the sagittal plane, with smooth edges formed by 16 small granular scales on each meatus. Mental scale hexagonal, longer than wide. Three postmental scales. Post-orbital region covered by granular scales. Scales of the gular region contiguous and cycloid in shape. Scales of the throat region imbricated, cycloid, and larger than the scales of the gular region. Fifty scales around the midbody. One hundred fifty-six dorsal scales. Vertebral line formed by two series of contiguous granular scales. Dorsal surface of the body with four series of moderately keeled scales on each side of the vertebral line and extended onto approximately the first 4 mm of the dorsal tail surface. First three longitudinal keeled series on each side of the vertebral line separated by two series of smaller granular scales. Third series of longitudinal keeled scales separated from lateral scales by one series of both cycloid and granular scales. Lateral scales in four contiguous series of moderately keeled scales. The fifth series of moderately keeled scales interspersed with cycloid scales at the ventral margin of the flanks. Axillar and inguinal region covered by small granular scales. Ventral scales cycloid and imbricate, with the posterior edge 3-5 lobed. Dorsal and anterior region of the arm and forearm covered with imbricate cycloid scales. Posterior and inner region of the arms covered with very small granular scales. Dorsal and anterior region of the thighs covered by keeled scales interspersed with cycloid scales, both scale types imbricate. Dorsal and anterior region of the lower leg covered by keeled scales. Ventral and posterior region of the lower leg covered by cycloid scales. Subdigital lamellae of the hands imbricate, numbering: I: 7/7; II: 10/10; III: 14/13; IV: 16/14; V: 11/12. Subdigital lamellae of the foot imbricate, numbering: I: 7/7; II: 9/9; III: 12/12; IV: 12/11; V: 9/10. Dorsal and lateral surface of the tail covered by cycloid and imbricate scales. Subcaudal scales imbricate, enlarged, and transversely rectangular. Lateral margin of the vent bordered by two smaller scales.
Coloration in vivo. Dorsal body side covered with irregular, dark brown spots with well-defined edges, which contrast sharply with the beige background, resulting in a well-marked reticulate pattern. Towards the flanks of the body, a continuous dark brown mark is extended from the posterior edge of the orbit to behind the insertion of the forelegs. Loreal regions covered with a dark spot extending from the snout tip to the anterior edge of the orbits. On the ventral body side, chest and abdomen immaculate gray; limbs, groin, neck, and head dirty brownish with dark chromatophores scattered on the scales.
Coloration in fixed specimens. On the body dorsum, the reticulate pattern tends to become black and the beige background coloration tends to become gray. On the ventral body side, the coloration remains the same, but less intense.
Variation. Based on ten adult females and four adult males ( Tables 1 View TABLE 1 , 2). UNNEC 11281 with six supralabial scales on left side and seven at right side, two postmental scales, and six infralabial scales on right side and five on left side. UNNEC 11277 with six infralabial scales on right side and five on left side. UNNEC 11297 with seven supralabial scales on left side and six on right side. UNNEC 11282 with seven supralabial scales on left side and eight on right side, two postmental scales. UNNEC 11283 with two postmental scales. UNNEC 11278 with six supralabial scales on left side and seven on right side. UNNEC 11284 with six supralabial scales on left side and seven on right side. UNNEC 11285 with two postmental scales, five infralabial scales on left side and six on right side. MLP. S. 5796 with six supralabial scales on each side, two postmental scales. UNNEC 11294 with six supralabial scales on left side and seven on right side, two postmental scales. UNNEC 11295 with six supralabial scales on left side and seven on right side, six infralabial scales on each side. UNNEC 11296 with two postmental scales, six infralabials on each side.
Etymology. The species epithet derives from the language of the South American Guarani culture, which inhabited the area currently corresponding to Corrientes Province. The term is translated as “lizard” (Vázquez de Espinosa, 1948; Sorg, 2007), but current inhabitants use it to refer to the territory of the province.
Distribution. Homonota taragui is currently only known from the hills at Paraje Tres Cerros, Corrientes Province, Argentina ( Fig. 1 View FIGURE 1 ). Field surveys around the base of the hills failed to find any specimens, suggesting that the new species is endemic in these hills.
Habitat. Rocky grasslands in which grasses and cacti are the dominant elements ( Fig. 8 View FIGURE 8 ; Parodi, 1943). Individuals are found under rocks that lay on a rocky substrate, and especially in sites where the rocks lay on large, exposed outcrops of quartz sandstone.
Reproduction. Gravid females of H. taragui where found during November and December, and the egg clutches in December. Egg clutches in the field and those laid by females in captivity consisted of a single egg ( Fig. 9 View FIGURE 9 ). This pattern is also observed in other species of the genus, such as H. borellii , H. fasciata and H. underwoodi (Gallardo, 1977; Abdala, 1997). In the field, egg clutches were laid under the rocks above cockroach droppings, and were always found with one to three adult individuals. Egg size (n = 4) were 9.82 mm ± 0.120 long (min = 9.72; max = 9.98), and had an average width of 7.7 mm ± 0.11 (min = 7.58; max = 7.86).
Other lizard species. Four other lizard species were found to occur syntopically with H. taragui , Cercosaura schreibersii, Cnemidophorus sp., Teius ocullatus , and Tupinambis merianae .
Conservation status. Individuals of H. taragui are common and easy to find on the hills of Paraje Tres Cerros. Yet, the extremely restricted range of distribution of this species indicates that it is potentially vulnerable to changes in environment. The rocky grassland of the hills is used as pasture for cattle. In surrounding areas, livestock activity with intentional fire set to promote grass growth for pasture represents the major threat for the hills’ fauna and flora. Provincial governmental authorities seem to be interested in protecting these hills by turning them into a nature reserve. We recommend that a monitoring study of the populations of H. taragui be included in the management plan of the future nature reserve. Such a study would allow us to understand population dynamics in this species, and accurately evaluate its conservation status.
MLP. UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC UNNEC
S 5796 11277 11278 11279 11281 11282 11283 11284 11285 11294 11295 11296 f I 7 /7 6/6 6/6 7/6 7/- -/6 6/6 8/8 6/6 9/- 7/8 7/7 f II 10/10 9 /9 10/9 10 /9 11/10 10 /10 10/9 10/10 10 /9 -/10 10/11 11 /10 f III 10/11 -/9 12/12 13 /12 12/12 12 /12 11/11 11 /- 12/11 10 /12 12/12 13 /12 f IV 12/12 12 /- 13/13 13/13 13/13 13/13 13/12 11 /12 12/13 12 /13 13/13 -/13 f V 9 /8 -/8 10/10 10 /10 10/10 11 /9 10/10 10 /10 9/9 11/10 10 / 10 11/10 h I 7 /7 6/6 6/6 6/7 7/7 8/8 7/8 8/8 7/7 8/8 7/8 8/8 h II 10/10 8 / 8 11/11 -/10 11/11 10 /10 10/10 10 /10 10/10 11 /11 11/11 11 /12 h III 13/13 -/ 12 14/13 14/14 12 /12 13/14 12 /13 13/13 13/13 14/15 -/ 11 14/14 h IV 10/8 14 /14 15/13 15/17 17/16 - 16/16 14/- 14/15 17/16 16/16 14/15 h V 12/12 11 / 12 13/13 14/14 14/14 14/14 -/12 12/13 13 / 11 14/14 13/- 14/-
TABLE 1. Morphometric and meristic variation within Homonota taragui sp. nov. type series. Mean, standard deviation (±), and range (given in parentheses) are in mm for size measurements, and in numbers for scales quantity. See Materials and Methods for abbreviations.
| Males (N = 4) | Females (N = 10) | |
|---|---|---|
| SVL | 39.45 ± 0.97 (38.25-40.35) | 39.43 ± 1.62 (36.72-41.86) |
| CL | 43.11 ± 1.48 (41.12-44.64) | 34.77 ± 14.19 (12.86-51.66) |
| HL | 10.20 ± 0.62 (9.3-10.73) | 10.14 ± 0.67 (8.78-10.91) |
| HW | 8.23 ± 0.68 (7.22-8.77) | 7.85 ± 0.33 (7.35-8.47) |
| ED | 2.18 ± 0.09 (2.07-2.29) | 2.24 ± 0.16 (2.05-2.53) |
| EOD | 0.62 ± 0.16 (0.41-0.8) | 0.65 ± 0.10 (0.43-0.76) |
| NEL | 3.17 ± 0.22 (2.91-3.47) | 2.97 ± 0.27 (2.51-3.25) |
| EEOD | 3.66 ± 0.08 (3.58-3.74) | 3.25 ± 0.32 (2.54-3.55) |
| VW | 4.09 ± 0.29 (3.79-4.42) | 3.94 ± 0.35 (2.36-4.43) |
| SAM | 53 ± 2.16 (50-55) | 55.33 ± 3 (52-60) |
| DS | 125.5 ± 15.63 (105-143) | 129.22 ± 9.47 (119-149) |
| KSLT | 10.25 ± 2.21 (7-12) | 9.55 ± 1.66 (8-13) |
| KSRT | 9.75 ± 4.27 (5-15) | 8.44 ± 1.81 (5-10) |
| MLP |
Museo de La Plata |
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