A New Alligator Lizard from Northeastern Mexico

A New Alligator Lizard from Northeastern Mexico Author(s) :Robert W. Bryson Jr. and Matthew R. Graham Source: Herpetologica, 66(1):92-98. 2010. Published By: The Herpetologists' League DOI: 10.1655/09-012.1 URL: http://www.bioone.org/doi/full/10.1655/09-012.1 BioOne (www.bioone.org) is a a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.

Herpetologica, 66(1), 2010, 92 98 E 2010 by The Herpetologists League, Inc. A NEW ALLIGATOR LIZARD FROM NORTHEASTERN MEXICO ROBERT W. BRYSON, JR. 1,2 AND MATTHEW R. GRAHAM 1 1 School of Life Sciences, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4004, USA ABSTRACT: A new alligator lizard is described from the Chihuahuan Desert in southwestern Tamaulipas, Mexico. This lizard appears to be most closely related to the smooth-scaled, relatively small-bodied alligator lizards Gerrhonotus lugoi, from the Cuatro Ciénegas Basin of central Coahuila, and G. parvus, from the central part of Nuevo León, but differs from these species, especially G. parvus, in a number of morphological characters. We tentatively place our new species in the genus Gerrhonotus alongside G. lugoi and G. parvus, but concede that future research is needed to ascertain the phylogenetic placement of these smooth-scaled gerrhonotine lizards. RESUMEN: Se describe una nueva y distintiva lagartija gerrhonotina del Desierto Chihuahuense en el suroeste de Tamaulipas. Esta lagartija está más estrechamente emparentada con la lagartija de escamas lisas y cuerpo relativamente pequeño Gerrhonotus lugoi, de la Cuenca de Cuatro Ciénegas en el centro de Coahuila, y con G. parvus, de la parte central de Nuevo León, pero difiere de estas especies, especialmente de G. parvus, enunnúmero de caracteres morfológicos. Tentativamente, se ubica a la nueva especie en el género Gerrhonotus junto con G. lugoi y G. parvus, aunque se admite la necesidad de investigación futura para discernir la ubicación filogenética de estas lagartijas gerrhonotinas de escamas lisas. Key words: Anguidae; Gerrhonotus farri; Gerrhonotus lugoi; Gerrhonotus parvus; Reptilia; Tamaulipas ANGUID diversity in northeastern Mexico is relatively high. Four genera and seven putative species of alligator lizards occur in this region, which encompasses the states of Coahuila, Nuevo León, Tamaulipas, and San Luis Potosí. Several of these species, however, are known from fewer than a dozen specimens each. These include Anguis incomptus (four known specimens [Farr et al., 2007; Terán- Juárez, 2008]), Gerrhonotus lugoi (nine specimens [Lazcano et al., 1993]), and G. parvus (seven specimens [Banda et al., 2005]). The rarity of these lizards in collections is surprising considering the decades of field efforts logged by various herpetologists to catalog the reptiles and amphibians of this region (reviewed in Flores-Villela and Pérez-Mendoza, 2006). During recent field work conducted by the Universidad Autónoma de Nuevo León (UANL) and the Houston Zoo to document the herpetological diversity of Tamaulipas, a distinctive new alligator lizard was collected southwest of Tula in the arid limestone foothills of the Sierra Madre Oriental in Chihuahuan Desert scrub. Herein we describe this new species, which appears to be closely related to G. lugoi, a purported 2 CORRESPONDENCE: e-mail, brysonjr@unlv.nevada.edu endemic of the Cuatro Ciénegas Basin of central Coahuila, and G. parvus, a Nuevo León endemic. MATERIALS AND METHODS Protocols for scale counts and definitions of external morphological features follow Good (1988). The body and tail were measured using a meter stick to the nearest 0.5 mm; all other measurements were made to the nearest 0.1 mm with a vernier caliper. Scale counts were made with the aid of a dissecting microscope. Meristic asymmetry is reported as left/right. The type specimen was preserved in 10% formalin and subsequently placed in 70% ethanol; therefore, tissues were unavailable to us for molecular analyses. Color descriptions were made from the alcoholpreserved specimen, and from color photos of the holotype before preservation. A list of the comparative specimens examined is provided in the Appendix. Excluding type specimens, we examined all known specimens of G. lugoi (two specimens reported by Lazcano et al. [1993] were subsequently lost), and all preserved specimens of G. parvus (five live lizards in the UANL collection were not examined). Scale counts and measurements for type specimens were obtained from McCoy (1970) and Knight and Scudday 92

March 2010] HERPETOLOGICA 93 FIG. 2. Gerrhonotus farri (holotype, UANL 6600), dorsal and lateral views of head. Scale bar represents 5 mm. FIG. 1. (A) Body and (B) head of holotype of Gerrhonotus farri (UANL 6600, adult male, snout vent length 5 109 mm). (1985). The coordinates and elevation of the type locality were determined using a handheld global positioning system unit by the collectors. Abbreviations used for museum specimens follow Leviton et al. (1985) and Flores-Villela and Hernández (1992). SPECIES DESCRIPTION Gerrhonotus farri sp. nov. Holotype. UANL 6600, an adult male collected by William L. Farr, Toby J. Hibbitts (field number TJH 881), and James R. Dixon on 26 September 2006, from north of Magdaleno Cedillo, 27 km southwest of Tula, Municipio Tula, Tamaulipas, Mexico (22u 499 33.60 N, 99u 549 28.20 W, WGS84; 1067 m elevation; Figs. 1 3). Diagnosis. Gerrhonotus farri can be distinguished from all other gerrhonotine lizards except G. lugoi and G. parvus in having smooth dorsal scales. Gerrhonotus farri, G. lugoi, and G. parvus lack a postrostral, further differentiating these species from other Gerrhonotus. Gerrhonotus farri and G. lugoi differ from G. parvus by possessing anterior internasals and a head very distinct from the neck, and by lacking rostral nasal contact, contact between the supranasals, and cantholoreals. From G. lugoi, G. farri differs in number of longitudinal dorsal scale rows (14 vs. 18 19), longitudinal ventral scale rows (12 vs. 14), suboculars (2 vs. 3), and primary temporals (4 vs. 5). Furthermore, G. farri is longer (109 mm vs. 94 mm snout vent length [SVL]) and more robust than G. lugoi, and possesses a unique color pattern of white stippling on the head and suffusion of dark-edged white dots dorsolaterally, seen only in one other specimen of G. parvus (UANL 6220). These differences are summarized in Table 1. Of questionable importance is the presence of two seemingly azygous, longitudinally oriented scales separating the prefrontals in G. farri (Fig. 2). These scales were not present in any of the other specimens we examined, and not reported by Good (1988) after his examination of nearly 1000 gerrhontine lizards. To our knowledge, no other gerrhonotine lizards have these scales. Description of the holotype. Measurements in millimeters: SVL, 109.0; greatest width of body, 23.0; width at base of tail, 12.3; width of head, 24.0; length of head, 29.7 (anterior margin of ear opening to tip of snout); snout length (from anterior region of eye to tip of snout), 10.0; depth of head, 16.5 (at widest point); orbital diameter, 4.9; axilla to groin, left 59.0, right 56.7; length of forelimb, left 26.0, right 28.0; length of hindlimb, left 33.0, right

94 HERPETOLOGICA [Vol. 66, No. 1 FIG. 3. (A) Gerrhonotus lugoi (photographed in the wild) and habitat at the type locality, Sierra de San Marcos y Pinos, Coahuila, Mexico; (B) G. parvus (UANL 6832) and habitat, Cañon San Isidro, Nuevo León, Mexico; and (C) G. farri (holotype, UANL 6600) and habitat at the type locality, north of Magdaleno Cedillo, 27 km southwest of Tula, Tamaulipas, Mexico. 35.0; longest finger, 5.3; longest toe, 9.0; tail length, 39.0 (most missing). Head large, conspicuously wider than neck, especially between posterior region of the eye and anterior of ear. Head scales convex, smooth, and glossy. Postrostral absent; anterior internasals 1/1, both divided, forming a transverse series of four scales; posterior internasals 1/1; primary temporals 4/4, first and second in contact with fifth medial supraocular; secondary temporals 4/4; preoculars 1/1, uppermost in contact with superciliaries; postoculars 2/3; suboculars 2/2, with posterior subocular scale more than two times longer than anterior scale; superciliaries 6/6; loreals 2/2; canthals 2/2; postnasals 2/2; frontonasal large and separated from frontal by two prefrontals at outer edges, and two

March 2010] HERPETOLOGICA 95 TABLE 1. Selected mensural and scalation characteristics for the three smooth-scaled species of gerrhonotine lizards from northeastern Mexico. Included are data reported by McCoy (1970) and Knight and Scudday (1985) for the type series of Gerrhonotus lugoi (n 5 2) and G. parvus (n 5 2), respectively. Characters Gerrhonotus farri (n 5 1) Gerrhonotus lugoi (n 5 7) Gerrhonotus parvus (n 5 6) Snout vent length (maximum) 109 94 76.5 Rostral nasal contact no no yes Supranasal contact no no yes Cantholoreal present no no yes Anterior internasals present yes yes no Preoculars 1 1 2 absent Postoculars 2 3 2 3 3 Suboculars 2 3 3 Primary temporals 4 5 4 Longitudinal dorsal scale rows 14 18 19 16 Longitudinal ventral scale rows 12 14 12 longitudinally oriented azygous, roughly diamond-shaped scales interiorly; two azygous scales arranged longitudinally and meet to separate prefrontals, with anterior scale attached under frontonasal and posterior attached under prefrontal; frontal enlarged and tapered distally, forming an apex; supralabials 12/11; infralabials 10/10; two postmentals; sublabials 6/6, large, and in contact with postmentals; chinshields 5/5. Body slender with small limbs and feeble digits typical of Gerrhonotus species. Hind limbs approximately twice as robust as forelimbs. Lateral fold is comprised of numerous granular scales forming no distinct rows. Dorsal scales in 53 transverse and 14 longitudinal rows. Ventral scales in 60 transverse and 12 longitudinal rows. Hemipenes everted. In preservative, head scales with base color of light to dark brown and speckled with whitish spots or blotches, usually no more than one per scale. Supralabials brown but outlined with white lines and spots, especially where dorsal edge contacts loreals and preoculars. Dorsal base color light brown to tan with sparse whitish flecking. Dorsum from neck to end of tail with dark brown crossbands spotted with white. Crossbands one to two scales wide and six to seven scales long, with dark-edged white spots arranged one per scale column and usually in center of distal edge of anterior scales. Base color laterally, excluding the cream-colored lateral fold, is darker due to suffusion of numerous dark-edged white spots. White spots usually arranged one per scale and located on distal edge with some continuing over into dorsal edge of lateral fold, especially near front legs, and onto proximal base of hind leg dorsal scales. Eighth crossband (counted from neck to tail) Y-shaped with top of Y on left side, so crossbands from neck to tail range from 12 to 13, corresponding to right and left sides respectively. All crossbands separated by light brown to tan rows of scales which each possess a very fine line, slightly lighter in color, running along posterior scale edges; first and second crossbands separated by four rows of these scales; all other crossbands between neck and tail separated by two rows. Legs pale tan to white except for three to four scales with white dots on dorsal surface where the hind legs attach to body. Venter immaculate and white. In life, coloration of dorsal and lateral scales more complex than in preservative. Base color brown to dark brown (light brown to tan in preservative), and crossbands very dark brown to nearly black (light brown to tan in preservative). Spots are lighter in color, strongly in contrast with dark-colored crossbands, and dark edges surrounding spots more distinct. Legs light mahogany (light tan to white in preservative). Habitat and ecology. The only known specimen of G. farri was collected southwest of Tula in the arid limestone foothills of the Sierra Madre Oriental in Chihuahuan Desert scrub (Figs. 3 and 4). This area is characterized by relatively dense low-growing desert shrubs, such as creosote bush (Larrea tridentata), mariola (Parthenium incanum), and tall yuccas (Yucca filifera, Y. faxoniana), with scattered dense clumps of false agave (Hechtia texensis) and various cacti (Opuntia spp., Cylindropuntia sp.). The collector s field

96 HERPETOLOGICA [Vol. 66, No. 1 FIG. 4. Distribution of known localities of Gerrhonotus lugoi (circles), G. parvus (squares), and G. farri (star). White symbols indicate type localities. notes indicate the lizard was found at 0927 h in a tillandsia (presumably a clump of false agave). The ambient air temperature was 24 C. Etymology. The specific epithet, an unlatinized noun in the genitive singular case, is a patronym honoring William L. Farr. William has logged many hours in the field as part of a collaborative effort between the UANL and the Houston Zoo to document the herpetological diversity of Tamaulipas. His efforts to date have resulted in the discovery of nine state records and nine distributional extensions (Farr et al., 2007), and the collection of the only known specimen of G. farri. DISCUSSION Our examination of additional specimens of G. lugoi revealed previously undocumented variation in size and scale counts. The largest G. lugoi (in terms of SVL) we examined was 94 mm (UANL 4284); the SVL of the holotype and paratype were reported as 79.4 and 74.8 mm (McCoy, 1970). Additional counts are as follows (holotype and paratype counts in parentheses): supralabials, 12 14 (13 14); infralabials, 10 12 (11 12); preoculars, 1 2 (2); postoculars, 2 3 (3); longitudinal dorsal scale rows, 18 19 (18). Good (1994) stated that two specimens of G. lugoi had four scales in the first temporal row. We count five primary temporals on the TCWC specimen examined by Good, and the original description of G. lugoi states that the holotype (and presumably the paratype) has five primary temporals. All other G. lugoi we examined also had five primary temporals. The phylogenetic placement of G. lugoi and G. parvus has been contentious for several decades. Although both taxa were originally placed within the genus Gerrhonotus, various authors have suggested this placement to be incorrect. Waddick and Smith (1974) placed G. lugoi into the genus Barisia, and Smith (1986) later supported this claim by arguing that certain features of scalation (particularly the absence of a postrostral and subsequent medial contact of the anterior internasals) distinguish G. lugoi from other Gerrhonotus, and instead conforms with the generic characters of Barisia. Good (1988) disagreed and suggested that the characters that ally G. lugoi with Barisia discussed by Smith (1986) are ancestral for the subfamily Gerrhonotinae, and suggested the original generic placement within Gerrhonotus to be correct. Good (1994) later tested species limits within Gerrhonotus based on phylogenetic analyses of scalation, coloration, and morphometric variation, and concluded that G. lugoi was

March 2010] HERPETOLOGICA 97 closely related to G. infernalis (although based on a single synapomorphy of a reduction in tail whorl number). Morafka (1977) proposed that G. lugoi was simply an elevational clinal variant of G. infernalis. The phylogenetic placement of G. parvus has been even more problematic. Knight and Scudday (1985) placed G. parvus into Gerrhonotus without commenting on its possible placement within other genera, other than to note that G. parvus closely resembled neither G. liocephalus nor B. imbricata, but appeared to be closely related to G. lugoi. Soon after, Smith (1986) moved G. parvus into the genus Elgaria. This allocation, later supported by Good (1988), was based on a number of scale characters shared between and unique to Elgaria and G. parvus. These characters include nasal rostral contact, anterior internasal absence, and contacting supranasals, and are all related to loss of the anterior internasal and thereby not independent. Subsequent phylogenetic analyses based on mitochondrial DNA (Conroy et al., 2005), however, strongly supported the placement of G. parvus as sister to other Gerrhonotus, and distantly related to Elgaria. Both Knight and Scudday (1985) and Good (1988) acknowledge the presence of two presumably derived morphological characters shared between G. lugoi and G. parvus: small size and smooth, glossy dorsal scales. Based on these shared characteristics, Knight and Scudday (1985) concluded that G. lugoi and G. parvus are more closely related to each other than to other gerrhonotine lizards. Although larger than both G. lugoi and G. parvus, G. farri shares with these taxa the unique feature of smooth dorsal scales. Similar scalation between G. farri and G. lugoi (e.g., presence of anterior internasals and lack of postnasals, rostral nasal contact, contact between the supranasals, and cantholoreals) suggest these two species are closely related. Their phylogenetic affinities with G. parvus, however, remain uncertain. Gerrhonotus parvus possess a suite of morphological features not found in either of these taxa, or in other Gerrhonotus. Molecular evidence, however, suggests a close relationship between G. parvus and other Gerrhonotus (Conroy et al., 2005). Thus it seems appropriate to place our new species in the genus Gerrhonotus, but concede that future research is needed to better ascertain the phylogenetic relationships of the three smooth-scaled species of Gerrhonotus to each other and to other gerrhonotines. The three species of smooth-scaled alligator lizards are each known from relatively few specimens from small, disjunct geographic regions (Fig. 4). Gerrhonotus lugoi is known only from the Sierra de San Marcos y Pinos and Sierra de la Madera mountains surrounding the Cuatro Ciénegas Basin in Coahuila. These mountains are separated from the Sierra Madre Oriental by a series of low arid valleys along the Coahuila Nuevo León border to the east, and west of Saltillo to the south. The southernmost locality of G. lugoi is more than 565 km from the type locality for G. farri on the foothills of the Sierra Madre Oriental. Gerrhonotus farri was found at the southern terminus of rocky foothills that extend from Magdaleno Cedillo north to the junction of Tamaulipas, Nuevo León, and San Luis Potosí and into Nuevo León. Known localities for G. parvus lie within the rocky folds of the Sierra Madre Oriental from near Galeana north to San Isidro, Nuevo León, although this lizard is expected to also occur in adjacent Coahuila (Lemos-Espinal and Smith, 2007; Mendoza-Quijano et al., 2006). Little is known about the ecology and behavior of G. lugoi, G. parvus, and G. farri. All three species appear to be crepuscular. The holotype of G. lugoi was collected while actively crawling on a rock slide at dusk (McCoy, 1970), and other G. lugoi were also found in the evening (Lazcano et al., 1993). One G. parvus was found crawling along the base of a canyon wall at 1630 h (Banda-Leal et al., 2002). The holotype of G. farri was found active at 0927 h. Museum data and published records (Bryson et al., 2003; Knight and Scudday, 1985) suggest that G. lugoi and G. parvus are also frequently found beneath dead agaves and yuccas. Acknowledgments. We are indebted to UANL (D. Lazcano), LACM (R. Feeney), TCWC (T. J. Hibbitts), and MZFC (A. Nieto-Montes de Oca) for the loan of critical material. We thank T. J. Hibbitts, U. Garcia, and A. Nieto-Montes de Oca for assistance with scale counts; T. J. Hibbitts, M. Price, A. Ambos, E. García-Padilla, and J. Jones for allowing the use of their photos (TJH, G. farri; MP, G. parvus UANL 6832; AA, G. lugoi; EGP, G. lugoi

98 HERPETOLOGICA [Vol. 66, No. 1 habitat; JJ, G. farri habitat); M. Powell and J. Henrickson for assistance with plant identifications; A. Nieto-Montes de Oca for the Spanish translation of the abstract; W. L. Farr, J. R. Dixon, M. R. J. Forstner, T. J. Hibbitts, D. Lazcano, A. Kardon, B. R. Riddle, J. Jaeger, A. Nieto- Montes de Oca, and C. Conroy for advice and logistical support; and several anonymous reviewers for providing comments that greatly improved the final manuscript. Collecting in Mexico was conducted under permits granted to D. Lazcano by SEMARNAT (01624). LITERATURE CITED BANDA, J., R. W. BRYSON, AND D. LAZCANO. 2005. Gerrhonotus parvus. Maximum size. Herpetological Review 36:449. BANDA-LEAL, J., R. W. BRYSON, AND D. LAZCANO. 2002. A new record of Elgaria parva (Lacertilia: Anguidae) from Nuevo León México. Southwestern Naturalist 47:614 615. BRYSON, R. W., D. LAZCANO, J. BANDA, C. GARCIA, AND G. CASTAÑEDA. 2003. Historia natural de la lagartija pigmea (Elgaria parva) endémica de Nuevo León, México. Boletín de la Sociedad Herpetológica Mexicana 11:21 22. CONROY, C. J., R. W. BRYSON, D. LAZCANO, AND A. KNIGHT. 2005. Phylogenetic position of the pygmy alligator lizard based on mitochondrial DNA. Journal of Herpetology 39:142 147. FARR, W. L., P. A. LAVÍN-MURCIO, AND D. LAZCANO. 2007. New distributional records for amphibians and reptiles from the state of Tamaulipas, Mexico. Herpetological Review 38:226 233. FLORES-VILLELA, O. A., AND J. A. HERNÁNDEZ. 1992. Las coleccions herpetológicas Mexicanas. Publicaciones Especiales del Museo de Zoología de la Facultad de de Ciencias, UNAM 4:1 24. FLORES-VILLELA, O., AND H. A. PÉREZ-MENDOZA. 2006. Herpetofaunas estatales de México. Pp. 327 346. In A. Ramírez-Bautista, L. Canseco-Márquez, and F. Mendoza-Quijano (Eds.), Inventarios Herpetofaunísticos de México: Avances en el Conocimiento de Su Biodiversidad. Publicaciones de la Sociedad Herpetológica Mexicana 3. S y G editors SA de CV, Coyoacán, México DF, México. GOOD, D. A. 1988. Phylogenetic relationships among gerrhonotine lizards. An analysis of external morphology. University of California Publications in Zoology 121:1 139. GOOD, D. A. 1994. Species limits in the genus Gerrhonotus (Squamata:Anguidae). Herpetological Monographs 8:180 202. KNIGHT, R. A., AND J. F. SCUDDAY. 1985. A new Gerrhonotus (Lacertilia: Anguidae) from the Sierra Madre Oriental, Nuevo León, Mexico. Southwestern Naturalist 30:89 94. LAZCANO, D., A. CONTRERAS-ARQUIETA, AND M. NEVARES DE LOS REYES. 1993. Notes on Mexican herpetofauna 3: Reproductive biology of Gerrhonotus lugoi, an anguid lizard from the Cuatro Cienegas Basin, Coahuila, Mexico. Bulletin of the Chicago Herpetological Society 28:263 265. LEMOS-ESPINAL, J. A., AND H. M. SMITH. 2007. Anfibios y Reptiles del Estado de Coahuila, México. UNAM/ CONABIO, México DF, México. LEVITON, A. E., R. H. GIBBS, JR., E. HEAL, AND C. E. DAWSON. 1985. Standards in herpetology and ichthyology: Part I. Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia 1985:802 832. MCCOY, C. J. 1970. A new alligator lizard (genus Gerrhonotus) from the Cuatro Cienegas Basin, Coahuila, Mexico. Southwestern Naturalist 15:37 44. MENDOZA-QUIJANO, F., A. GONZÁLEZ-ALONSO, E. A. LINER, AND R. W. BRYSON. 2006. Una synopsis de la herpetofauna de Coahuila. Pp. 24 47. In A. Ramírez- Bautista, L. Canseco-Márquez, and F. Mendoza- Quijano (Eds.), Inventarios Herpetofaunísticos de México: Avances en el Conocimiento de Su Biodiversidad. Publicaciones de la Sociedad Herpetológica Mexicana 3. S y G editors SA de CV, Coyoacán, México DF, México. MORAFKA, D. J. 1977. A biogeographical analysis of the Chihuahuan desert through its herpetofauna. Biogeographica 9:1 313. SMITH, H. M. 1986. The generic allocation of two species of Mexican anguid lizards. Bulletin of the Maryland Herpetological Society 22:21 22. TERÁN-JUÁREZ, S. A. 2008. Anguis incomptus (Sauria: Anguidae) una adición a la herpetofauna de Tamaulipas, México. Acta Zoológica Mexicana 24:235 238. WADDICK, J. W., AND H. M. SMITH. 1974. The significance of scale characters in evaluation of the lizard genera Gerrhonotus, Elgaria, and Barisia. Great Basin Naturalist 34:257 266..Accepted: 21 December 2009.Associate Editor: Christopher Raxworthy APPENDIX I Records for Smooth-scaled Gerrhonotus Specimens examined. Gerrhonotus farri: Tamaulipas: N of Magdaleno Cedillo, 27 km SW of Tula (holotype; UANL 6600). Gerrhonotus lugoi: Coahuila: N tip of Sierra de San Marcos, ca. 11 km SW of Cuatro Ciéngas de Carranza, vicinity of Lote Amalia Margarita (LACM 116254); Montañas al norte de Ejido Nueva Atalaya (MZFC 23318); 14.2 mi W of Ocampo (TCWC 55258); Enfrente de la Poza La Becerra en la Sierra de San Marcos (UANL 4040); Terrecería enfrente de la Poza Churince, Cañón de San Marcos (UANL 4284). Gerrhonotus parvus: Nuevo León: Cañon San Isidro (UANL 5844, UANL 6621, UANL 6675, UANL 6785). Additional specimens. Gerrhonotus lugoi: Coahuila: 2.7 km SW of Cuatro Ciénegas de Carranza (paratype; ASU 8818); N tip of Sierra de San Marcos, approximately 11 km SW of Cuatro Ciénegas de Carranza (holotype; CM 49012). Gerrhonotus parvus: Nuevo León: 3 km SE of Galeana (SRSU 5538); 1 km S of Galeana (SRSU 5537); Galeana (UANL 6208); Cañon San Isidro (UANL 6797, 6832, 6904); Los Rayones (UANL 6220).