Liolaemus duellmani is a poorly known, microendemic lizard described from southwestern Mendoza, Argentina, representing the southernmost distribution of the Liolaemus montanus species group. We report the rediscovery of the species after 43 years, presenting the fifth voucher specimen and the second female of L. duellmani. Data on external morphology, activity, and color photographs are included, and the geographic coordinates of the type locality are discussed.
The microendemic species Liolaemus duellmani Cei, 1978 has for a long time been considered enigmatic. It was categorized as Insuficientemente conocida (insufficiently known) by the Asociación Herpetológica Argentina in 2012 (Abdala et al., 2012) and as “Data deficient” by IUCN (IUCN, 2017). The species has not been collected since 12 December 1974, when W.E. Duellman and J.E. Simmons collected the holotype and two paratypes, all of them males (KU 161126 holotype, KU 161127–128 paratypes). The fourth specimen in the type series, the only known female, was collected previously by Cei on 22 November 1961 (IBA-UNC 139).
Several field trips to the supposed type locality of Liolaemus duellmani in Mendoza province were carried out by the authors with the aim of rediscovering the species described by Cei (1978). On 11 January 2017, we found an adult female L. duellmani (MACN 51578; Fig. 1) in Pampa del Choique, 36°22′08.6″S, 69°46′01.2″W, 2,432 m above sea level, 3.36 km (airline) east of Paso del Choique, Malargüe department, Mendoza province, Argentina (Fig. 2). Here, we present new data on squamation, morphometry, activity, distribution, and full color photographs of a female of the species for the first time.
MATERIALS AND METHODS
All measurements are expressed in millimeters and were taken with a digital caliper (Schwyz, Electronic Caliper) to the nearest 0.02 mm. Pictures of the live specimen were taken in the field using a digital single-lens reflex camera (Nikon D7000), and most character details were examined under a stereomicroscope (Olympus SZ-ST). Characters used in the description followed standards published in Smith (1946), Cei (1986, 1993), Laurent (1984, 1986), Etheridge (1995, 2000), Abdala and Quinteros (2008), and Abdala et al. (2008, 2009, 2013). Geographic coordinates and elevation were obtained in the field with a GPS device (datum WGS84). The acronym MACN corresponds to Colección Nacional de Herpetología housed at División Herpetología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Ciudad Autónoma de Buenos Aires, Argentina.
Description of MACN 51578
Female, snout–vent length (SVL) 76.64. Trunk length 38.02. Head length 14.86. Head width 12.57. Head height (at parietal) 9.12. Eye diameter 3.63. Interorbital distance 6.28. Orbit–auditory meatus distance 5.53. Auditory meatus height 2.66, width 1.99. Orbit–commissure of mouth distance 2.09. Distance between nares 3.03. Subocular scale 4.56. Femur 10.59, tibia 12.53, foot 18.71, humerus 7.72. Humerus width 4.33. Tail length 71.35 (regenerated). Abdominal width 25.83.
Dorsal surface of head smooth, with 16 scales (from occiput to rostral scale). Rostral scale wider than high, bordered by 6 scales. Mental scale larger than rostral, pentagonal, bordered by four scales. Rostral scale not in contact with nasal. Two postrostral scales. Four internasals. Nasal scale surround by eight scales, separated from canthal by two scales. Six scales between rostral and superciliaries. Seven scales between rostral and frontal. Unique frontal scale. Interparietal smaller than or equal to parietals, surrounded by seven scales. Seven superciliaries, 14 upper ciliaries. Supraorbital semicircles complete. Five and six enlarged supraoculars. Preocular scale separated from lorilabial row by one scale. Projecting scales on anterior and superior margin of auditory meatus absent. Twelve smooth horizontal temporals and 10 vertical temporals. Nine lorilabials, four in contact with subocular scale. Nine enlarged supralabials, not in contact with subocular scale. Six infralabials, second ventrally in contact with two scales. Five chinshields; second imbricate separated by two scales. Eighty-seven scales around midbody. Ninety-two dorsal scales, from occiput to hindlimbs, juxtaposed, smooth, with rounded anterior margins. One hundred and sixteen ventrals, larger than dorsals, flat, imbricated in abdominal region, subjuxtaposed in lateral regions. Forty-four gulars between auditory meatus, juxtaposed, smooth. Precloacal pores absent. Antehumeral scales flat, larger than dorsal scales, most with scale organ in anterior margin. Postauricular, rictal, and longitudinal nuchal folds inflated but conspicuous. Scales on lateral neck folds granular with scale organ in each. Forty-two scales along longitudinal fold, 55 scales between margin of antehumeral pocket and arm. Twenty-two subdigital lamellae on IV finger, twenty-six on toe IV. Flank scales rounded, smooth, with several small granular intercalated scales. Femoral patch absent. Infracarpal scales flat, imbricate, trifid. Infratarsals scales flat, imbricate, keeled.
Dorsum of head spotted with small dark gray dots distributed irregularly; subocular scale conspicuously white. Dorsum gray/light brown with transversal rows of dark spots, each bordered by light gray ones. Six to seven rows of dark spots at the middle of the trunk. Most of body speckled with white scales sparsely but homogeneously distributed, confined within dark spots. Hands, antebrachium, axilla, foot, and ventral surfaces of thighs bright yellow. Claws very conspicuous dark brown. Pattern of spots continuing over dorsum of tail but fusing along midline to form transversal bands. The background color of tail lighter than trunk (light pink). Throat pale gray speckled with darker gray spots. Abdominal region homogeneous dark gray, almost black, continuing over cloacal area and tail. Center of chest gray with sparse small yellow dots irregular distributed. Posterior margin of cloaca bright yellow.
Comparison between the original description of Liolaemus duellmani Cei, 1978 and the characters observed in the newly collected female specimen MACN 51578.
Color in preservative after fixation resembles live specimens, but bright yellow color is lost. Tail remains light pink.
The locality of MACN 51578 is situated 3.36 km airline east of the type locality provided by Cei (1978) in the original description of Liolaemus duellmani: Paso del Choique, 50 km SSW El Manzano, 2,260 m, Provincia de Mendoza, Argentina. However, Cei (1978) gave incorrect geographic coordinates (36°27′S, 60°50′W; as a typo he wrote 60 instead of 69) that correspond to an uncertain locality in Buenos Aires province, 804 km to the east. In agreement with the geographical context given by Cei (1978), the capture site in which specimen MACN 51578 was found (36°21′44.51″S, 69°48′12.90″W) could be close to the original area where the type specimens were collected. Moreover, the locality where specimen MACN 51578 was found coincides with habitat details given by Cei (1978): xeric, mountainous, Patagonian steppe environments with volcanic rocky outcrops and soil with loose gravel typical of cryogenic activity in the area.
These data correspond to the southernmost record of the Liolaemus montanus group, which has its northernmost distribution in central Peru (Abdala and Quinteros, 2014). MACN 51578 was found active at midday (13:30) near the road, basking on a small basaltic rock. Regarding biological data, other aspects of this species' life history remain unknown.
The color pattern fits the original description, and morphometric and squamation characters of specimen MACN 51578 coincide with the ranges given by Cei (1978), except for the following counts (MACN 51578/original description counts Cei ): supralabials 9/10; infralabials 6/7; gulars 44/48–50; scales around midbody 85/86–90; subdigital lamellae on IV finger 22/18; and subdigital lamellae on IV toe 26/20–21 (Table 1).
We are grateful to J. Faivovich MACN for allowing us to study specimens under his care. Financial support was partially provided to (AL) by Consejo de Investigaciones Científicas y Tecnológicas, a postdoctoral fellowship grant, and PICT 2015-1398. We thank two anonymous reviewers for their comments and suggestions that improved the manuscript.