Leiosaurus jaguaris, Laspiur, Alejandro, Acosta, Juan Carlos & Abdala, Cristian S., 2007

Laspiur, Alejandro, Acosta, Juan Carlos & Abdala, Cristian S., 2007, A new species of Leiosaurus (Iguania: Leiosauridae) from central-western Argentina, Zootaxa 1470, pp. 47-57 : 48-55

Leiosaurus jaguaris sp. nov.

Holotype. FML 17584. Adult male. Gualcamayo (29° 49´48.5” S; 68° 45´45.9” W) at 2.440 mts., Jáchal Department, San Juan Province. Col. J. Marinero, R. Buff y J. Villavicencio, September 31st, 2000.

Paratypes. IMCN-UNSJ 3002. Adult male. Riverbed of the Guandacol River (28° 57´S; 68° 46´W) at 2.762 mts., Coronel Felipe Varela Department. La Rioja Province. Col. M. Jordán and J. Márquez, February 6th, 2005.

FML 17585. Adult male. Between Entre Rios School and Villa Mercedes Town, Jáchal Department, San Juan Province. Col. C. Abdala, S. Barrionuevo y M.J. Tulli, November 5th, 2004.

FML 7484-95. 12 specimens. Between Punta de Agua and las Chacaritas, 33 km to the West of Alto Jagüe, General Lamadrid Department, La Rioja Province. Col. S. Torres, S. Kretzschmar, J.C. Moreta and C. Salvatierra, February, 1998.

Etymology. It makes reference to the aspect of the coloration pattern which is similar to the american feline Panthera onca .

Diagnosis. Leiosaurus jaguaris ( Fig. 1 ) belongs to the Leiosauridae family according to Frost et al., (2001). Together with Diplolaemus and Pristidactylus genera, Leiosaurus belongs to the Leiosaurinae subfamily ( Frost et al., 2001). It clearly differs from all other members of genus due to the dorsal coloration pattern, the lepidosis and morphometric characters. The dorsal coloration pattern of L. jaguaris presents dorsal markings on the vertebral line in form of circles or semicircles with diffuse borders, absent or faded dorsolateral markings, rounded marked tail or with irregular rings and ventral body with or without little markings or dark scales irregularly disposed while L. paronae presents big and defined “lily” shaped spots on the vertebral line, big dorsolateral and circular spots or transverse to the axis body, tail with alternate dark and light rings and ventrally body with clearly defined markings ( Fig. 2 ). Leiosaurus jaguaris presents dorsal and dorsolateral uniform and granular squamation which do not form a protruding crest over the vertebral line or groupings of dorsolateral scales in contrast to L. paronae which presents in its body (mainly over the vertebral line) protruding conical scales which are bigger than the rest and which are keeled forming a vertebral crest which is unique among the species of the group. Moreover, L. jaguaris present uniform head scales without two protruding scales placed to both sides and behind the interparietal scale, characteristic in L. paronae . Leiosaurus jaguaris presents gular and ventral rounded scales which are smooth and subjuxtaposed or juxtaposed while L. paronae has keeled conic gular scales that ending in nib and triangular ventrals, monocarinate and imbricate. Leiosaurus jaguaris presents dorsal markings on the vertebral line, but they are never “shark tooth” shaped like in L. bellii ( Fig. 3 ). Leiosaurus jaguaris has round ventral scales or little markings irregularly distributed while L. bellii has a darker abdomen with longitudinal thin markings and a white line on the central part of the abdomen; this character is absent in the species hereby described. The rostral scale of the L. jaguaris can not be distinguished form the supralabial ones; temporal region with a line of big scales which continues together with the scales of the subocular region, in contrast to the L. bellii , whose rostral scale is well differentiated and protruding with a rectangular form and whose temporal scales are more consistent with no big differenced scales. Moreover, L. jaguaris presents subdigital lamellae with mucrones in all the toes of feet and hands, while L. bellii presents subdigital lamellae without mucrones. Leiosaurus jaguaris presents a coloration pattern which is very different from the one of L. catamarcensis ( Fig. 4 ), which has diffuse spots on the vertebral line in form of circles or semicircles and a lot of circular little spots irregularly distributed and with different colours to give a tiger “striped” look, while in L. catamarcensis the dorsal spots are bigger and more defined with no little spots on the back of the body. Besides, L. jaguaris has a continuous or discontinuous dark line which follows the supralabial scales up to the auditory meatus and, as was stated before, present smooth ventral scales on the pectoral region, while in L. catamarcensis , in some specimens, presents some dark or orange supralabial scales and the ventral scales are lightly careened. Also ventrally, in the abdominal region, the scales of the L. jaguaris are juxtaposed while in L. catamarcensis are imbricate. In L. jaguaris there are not conic shaped scales protruding from the rest of the vertebral line in contrast to L. catamarcensis which presents some protruding scales, mainly on the front part of the body.

Description of Holotype. Adult male, snout-vent length (92.7 mm.). Tail length (114.5 mm.) measured from the base of the vent up to the distal end; length of the torso (59.2 mm.) measured from the base of the neck up to the vent; width of the torso (23.9 mm.). Big and distinctive triangular head 1.32 times longer (27.5 mm.) than wide (21 mm.), head height (15.5 mm.), eye diameter (5.7mm.), eye-upper lip distance (3.5 mm.), eye-ear length (11.2 mm.). Very narrow auditory meatus, height of (2.9 mm.), and width (1.4 mm.). Distance between nares (5.8 mm.). Snout length (10.2 mm.) measured from the end of snout to the orbit. Size of the thigh (20.7 mm.), tibia-fibula (18.4 mm.) and foot (23 mm.). Distance between anterior and posterior limbs (39.5 mm). Humerus length (17.1 mm.), forearm (14.4 mm.) and hand (13.8 mm.). Vent width (8.5 mm.). Tail thin and depressed, 1.9 times longer than torso. Gular fold complete. Rough dorsal surface of the head, cephalic irregular and sub-conic scales. Supraorbital semicircles not very differentiated, separated by two rows of cuspidate scales indistinct from 16–19 marginal scales also cuspidate which skirt the semicircles. These semicircles are occupied by tiny granular and juxtaposed scales indistinct from 17 irregular and non prominent superciliars. Frontal and front parietal scales not regionalized and subdivided, parietal scales softly cuspidate, always smaller than the interparietal, elongated and surrounded by 9 irregular scales, small pineal organ but recognizable. Temporal scales with small granular scales in the centre, surrounded to the anterior area by irregular scales which are strongly cuspidate and limited by an upper furrow of prominent variable in size and form scales. Granular tympanic scales not prominent. Rounded and prominent nasal scale, pentagonal canthal scale separated from the nasal scale by 2 scales. Irregular and small internasal scales. Rostral undistinguishable from postrostrals, flat prominent pentagonal mental scale, wider than high, in contact with 8 rounded postmentals, 18 pentagonal supralabials not very variable separated from the nasal scale by four rows of flat small scales, 17 pentagonal infralabials. No flattened snout, slightly prominent loreolabial area, irregular supranasal scales undistinguishable from loreolabials. One hundred seventy eight scales around the body. Two hundred eight round, smooth and imbricate ventral scales. Tail with cuspidate and imbricate dorsal and lateral scales. Smooth, rounded and imbricate infracauldal scales. Distal end of tail with regularly rectangular scales, strongly imbricate. Sub-rounded antehumeral scales, the same as antebrachial scales which are enlarged in the near end of the manus. Granular back antehumeral and antebranchial scales. Prominent, sub-conical fore tibial scales, plain, rounded back tibials. Fourth finger with 20 tricarenate subdigital lamellae and fourth foot finger with 34 tricarenate subdigital lamellae. Irregular post auricular fold and antehumeral fold well marked. Infracarpals and infratarsals imbricate bicarenate or tricarenate lamellae. Monocuspidate teeth.

Coloration in ethanol. Dorsally, head with numerous dark brown spots distributed irregularly and with a drawing with a light gray “whale tail” form surrounded by a black rim. Head with two parallel stripes of dark brown or black colour laterally. The wider stripe goes from the back of the eye up to the upper front area of the auditory meatus. The other one has the same colour, but it is thinner and broken; it goes over the supralabial scale to the lower front area of the auditory meatus. Ventrally the head has some diffused brown spots. Dorsal body of light gray colour with numerous spots and irregular dots of dark brown colour distributed all over the body and limbs in an irregular way. Vertebral stripe not very much distinguishable and three vertebral spots which are light gray in the centre and black in the rim with a reinforce form. The back irregular vertebral spots are not distinguishable. The sides of the body have numerous light brown spots of different sizes which are irregularly distributed. In ventral pattern, it has light gray body with few diffused dots. In a dorsal and ventral pattern, tail has same colour and pattern as the body.

Variation in paratypes. Based on fourteen adult individuals, seven males and seven females.

Morphometry and squamation. The head is longer (23.2 – 27.8 mm. x= 24.9 mm.) than wider (21.3 – 25.8 mm. x= 22.3 mm.) ( Fig. 5 ). Height of the head (14.4 – 18.5 mm. x = 14.7 mm.), neck is narrower than the head and trunk. Robust body, the length of the trunk is 1.3 times bigger in relation to the body and the snoutvent length is 2.8 times bigger in relation to the body. Snout-vent length in males and females jointly: (80.9 – 97.5 mm. x= 89.6 mm.). Tail length (88.2 – 115.9 mm. x= 98, 7 mm.). The tail length is 1.2 times longer than snout-vent length. Dorsal head surface is rough, formed by conical scales. Rostral divided in 2 or 4 scales. Among 3–5 rows of loreolabials of minor size than the supralabials. Fourteen – 22 supralabials. Seventeen – 20 infralabials. Distinguishable interparietal of bigger size than parietals and surrounded by 8 – 10 scales. Six– 8 scales in contact with the mental scale. Smaller granular auricular scales in the lower front margin of the meatus. Scales around the body (both sex overall) 189 – 212, x= 205, 2. Without precloacal pores in males and females. Very marked gular fold. Dorsal scales, granular, conical, which finish in end, juxtaposed without keels. Ventral scales are bigger than dorsal scales. Hands and feet subdigital tricarenate scales. Laminar infracarpal and infratarsal scales, imbricate and triffids.

Coloration. Dorsal head ( Fig. 5 ) with numerous dark brown spots and dots distributed irregularly and with a white or light gray “whale tail” drawing surrounded by a black or dark brown rim. This drawing is found in the other species in the genus. Two parallel dark brown or black stripes are distinguished in the head laterally. The widest stripe is found from the back part of the eye to the upper front area of the auditory meatus. The other stripe, same colour but thinner than the first one and broken in various specimens, is found from the supralabials scales to the lower front area of the auditory meatus. Ventrally, the head with numerous light and dark brown spots or stripes longitudinally to the body, in most cases with “cascade” appearance. Light brown or light grey dorsal body with numerous irregular spots or dark brown and light brown dots irregularly distributed all over the body and limbs. With marked vertebral line from the occiput to the upper limbs, then it mixes with big vertebral marks in reniforme form or in complete circle or broken in the middle. Such spots of light grey colour in the center and with various black or dark brown dots in the exterior rim. Five-7 vertebral spots. Some L. jaguaris specimens exhibit variation to this coloration pattern. The vertebral spots can be diffused or absent, or totally distinguishable and prominent. At the sides of the body it can be distinguished numerous spots of different size, dark brown or light brown distributed irregularly. Without paravertebral spots. Ventrally white or light gray body with some dots of the same colour as the back. Dorsal tail with the same pattern as the body; in some specimens the vertebral spots form incomplete rings. Ventral tail of the same colour as the abdomen, with some diffuse or immaculate spots.

Distribution. ( Fig.6 ). L. jaguaris is only known in Gualcamayo (type locality), San Juan Province, and near regions, such as Guandacol River to the north of type locality and to the west of Alto Jagüe, La Rioja Province.

Natural History and Discussion. Leiosaurus jaguaris lives in a high-altitude area where steppe grazing land with low vegetal coverage and prickly low height bushes predominate ( Fig. 7 ). Among the most common species are: Gochnatia glutinous, Heliotropium sp., Larrea cuneifolia, Plectocarpa tetracantha and P. ruogesii . The type specimen was associated to a bush of Larrea cuneifolia , in a stony substratum, other specimens under Gochnatia glutinous . It seems to be a marked association among the representatives of this kind to this type of biotopes in accordance with Cei (1986) in the description of the kind of habits of Leiosaurus . There is little information about the geographic distribution of Leiosaurus and little knowledge of the species included in the group. For Van Devender (1977), L. bellii highly depend, for protection, of his cryptical coloration. Also, a mighty bite allows this species to have a specialized diet based on Tenebrionidae beetles. Cei (1986) confirm this diet for L. catamarcensis and L. paronae . For reproduction, there is data about clutch size of a female of L. catamarcensis ( Blanco & Acosta, 2003) , which, in captivity, placed 10 eggs. About thermalphysiology in L. catamarcensis, Villavicencio et al., (2006) , established the selected temperature (27.8ºC), and get a thin range (7.9ºC) of max and min voluntaries temperatures or “set points”. However, the range of thermal tolerance is amazing wide (37.87 ºC), exhibiting eurithermy, a condition which relate this species with the thermal characteristics of its habitat, a best aptitude to resist low temperature. Probably, the thermalphysiology of L. catamarcensis , which lives on a warm and desert environment, with thermal variation, like the Argentinean “Monte”, strongly restrict the activity time (in the dawn or in the crepuscule), and the use of microhabitat (caves or tree branches). The thermal characteristics, mimicry and low mobility, are maybe the cause at the low numbers of register and specimens in collections.

Among the Leiosaurus species, there are variation in both, coloration patterns and lepidosis characters. Being these differences obvious when we differentiate L. jaguaris at L. paronae and L. bellii . However, the differences between these species, there are important similitude. The presence of smooth ventral scales in the pectoral zone is character states which allow us to differentiate L. jaguaris at L. catamarcensis , who exhibit slightly keeled ventral scales ( Koslowsky, 1898). In Frost et al., (2001), there is no mention about the “slightly keeled” state in this character. So, with this work, we contributed to a more exhaustive study of the known characters and adding new morphological characters, present in the taxon described here, for phylogenetic analysis. A general morphological study could establish the relationships between the new species and the others members of the genus. The sexual dichromatism present in the three species of the genus ( Frost et al., 2001) is not present in L. jaguaris . In the same work, this author indicate that the adult females of L. bellii ; L. paronae y L. catamarcensis are larger than adult males; this condition neither is present in L. jaguaris .

Figures

FIGURE 1. Leiosaurus sp. nov. (Paratype, FML 17585). Photo: Cristian S. Abdala.

FIGURE 2. Leiosaurus paronae Adult male, from Reserva Bosques Telteca. Mendoza. Photo: Leonardo Muñoz.

FIGURE 3. Leiosaurus bellii Adult male, from El Cortaderal, Malargüe Department, Mendoza Province. Photo: Cristian S. Abdala.

FIGURE 4. Leiosaurus catamarcensis Adult male, from Baldecitos, San Juan Province. Photo: Cristian S. Abdala.

FIGURE 5. Head of Leiosaurus sp. nov. (Paratype, FML 17585). Photo: Cristian S. Abdala.

FIGURE 6. Distribution of the Leiosaurus species of Argentina based in collections specimen (see Appendix 1).

FIGURE 7. View of habitat of Leiosaurus sp. nov. Type Locality. San Juan Province, Argentina. Photo: Alejandro Laspiur.