Article.

Zootaxa 3790 (3): 439 450 www.mapress.com/zootaxa/ Copyright 2014 Magnolia Press Article http://dx.doi.org/10.11646/zootaxa.3790.3.3 http://zoobank.org/urn:lsid:zoobank.org:pub:446d1195-e507-4d0a-92c1-289e20b4567a ISSN 1175-5326 (print edition) ZOOTAXA ISSN 1175-5334 (online edition) A new species of bunchgrass lizard (Squamata: Phrynosomatidae) from the southern sky islands of the Sierra Madre Occidental, Mexico JARED A. GRUMMER 1,2 & ROBERT W. BRYSON, JR. 1 1 Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Box 351800, Seattle, WA 98195-1800, USA 2 Corresponding author. E-mail: grummer@uw.edu Abstract A new species of bunchgrass lizard in the Sceloporus scalaris group is described from the southern portion of the Sierra Madre Occidental in Mexico. The new species, Sceloporus aurantius sp. nov., was previously confused with S. brownorum but differs from this and all but one species within the S. scalaris group by a lack of blue belly patches in males. It shares with S. chaneyi an absence of blue belly patches, but differs from this species in size, number of dorsal scales, number of scales around midbody, and presence of an un-patterned morph. The new species further differs from S. chaneyi, and all other species in the S. scalaris species group, by unique phylogenetic position revealed through species delimitation based on multi-locus nuclear DNA. Principal component analyses of 24 traditional morphological characters used to describe previous S. scalaris group taxa indicate that these characters may be of limited use to delineate species in this species group. However, male lateral and ventral coloration may still be an important character for diagnosing species. Key words: Aguascalientes, Jalisco, Reptilia, Sceloporus scalaris group, Zacatecas Resumen Se describe una especie nueva de lagartija de pastizal dentro del grupo Scelopous scalaris en la región sur de la Sierra Madre Occidental de México. La especie nueva, Sceloporus aurantius sp. nov., estaba considerada previamente como S. brownorum y difiere de todas las especies del grupo S. scalaris excepto de la especie S. chaneyi, debido a que los machos carecen de parches ventrales de color azul. Difiere de la especie S. chaneyi la cual también carece de parches, en el tamaño, número de escamas dorsales, número de escamas alrededor del cuerpo, y presencia de un morfo sin patrón. La especie nueva además difiere de S. chaneyi y de todas las especies del grupo S. scalaris, por tener una posición filogenética única basada en múltiples locus de DNA nuclear. El análisis de componentes principales de 24 caracteres morfológicos tradicionales utilizados previamente para describir los taxa dentro del grupo S. scalaris, indica que estos caracteres pueden tener un uso limitado para diagnosticar especies dentro del grupo. Sin embargo, la coloración ventral y lateral en los machos, aún es considerada un caracter importante para diagnosticar especies. Palabras claves: Aguascalientes, Jalisco, Reptilia, groupo de Sceloporus scalaris, Zacatecas Introduction The taxonomy of the Sceloporus scalaris species group has been in flux since its conception over 75 years ago (Smith 1937). Although the species group as originally described contained seven species and subspecies, this number has fluctuated from 11 species and subspecies (Watkins-Colwell et al. 2006) to only three monotypic species (Thomas & Dixon 1976). This is due in part to the additions of new species and subspecies (S. samcolemani Smith & Hall 1974; S. chaneyi Liner & Dixon 1992; and S. s. brownorum Smith, Watkins-Colwell, Lemos-Espinal, & Chizar 1997). However, much of the instability is caused by variability in several key morphological characters used to delineate taxa within the group. Previous descriptions have distinguished species Accepted by S. Carranza: 6 Mar. 2014; published: 22 Apr. 2014 439

and subspecies primarily based on the number of canthal scales, extent of throat barring, or color of semeion (lateral/ventral body) patches. Whereas Thomas & Dixon (1976) found these characters to be highly variable and of limited use to delineate subspecies, Smith et al. (1996) considered them to be critically important in distinguishing among the various species and subspecies within the group. A number of studies of the S. scalaris group based on molecular data have emerged during the past decade (Mink & Sites 1996; Benabib et al. 1997; Bryson et al. 2012; Grummer et al. 2014). These studies generally support the recognition of previously described species and suggest that several undescribed species may be present within the group (Bryson et al. 2012; Grummer et al. 2014). The S. scalaris group as currently recognized consists of S. aeneus Wiegmann 1828, S. bicanthalis Smith 1937, S. brownorum, S. chaneyi, S. goldmani Smith 1937, S. samcolemani, S. scalaris Wiegmann 1828, S. slevini Smith 1937, S. subniger Poglayen & Smith 1958, S. unicanthalis Smith 1937, and three undescribed species (Grummer et al. 2014). FIGURE 1. Distribution of bunchgrass lizards in the Sceloporus scalaris group included in this study. Stars denote the known localities of Sceloporus aurantius sp. nov. (yellow star is type locality). Colors of S. brownorum, S. scalaris, S. slevini, and S. unicanthalis match the colors in principal components analyses results presented in Figure 3. 440 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON

Within the S. scalaris group, S. chaneyi is the only described species characterized by an absence of blue belly patches in males (Liner & Dixon 1992). This small species is restricted to high-elevation pine-oak forests in the northern Sierra Madre Oriental of eastern Mexico (Watkins-Colwell et al. 1996; Fig. 1). Recently we discovered a population of S. brownorum in the oak forest of the Sierra del Laurel mountains in southwestern Mexico that contained males with orange lateral streaks and no blue belly patches. Males of this population differed from S. brownorum to the north that have only blue belly bars (Smith et al. 1997). Interestingly, specimens from the Sierra del Laurel were part of the type series of S. brownorum (Smith et al. 1997). Grummer et al. (2014) tested species limits within the S. scalaris group using multi-locus data and found compelling genetic evidence that this population represents a distinct species (Fig. 2). Here we describe this new species, which represents the eleventh species within the S. scalaris group. FIGURE 2. Multi-locus species tree from Grummer et al. (2014) derived from coalescent-based analyses of 4,635 base pairs of nuclear DNA. The phylogenetic distinctiveness of Sceloporus aurantius sp. nov. was supported by Bayes factor species delimitation. Numbers at nodes represent Bayesian posterior probability support values. Materials and methods Molecular species delimitation. In a previous study (Grummer et al. 2014), we generated a multi-locus nuclear DNA (ndna) dataset to test species limits in the S. scalaris group. Because this dataset helps establish the distinctiveness of the new species from the Sierra del Laurel in relation to other species in the group, we include a summary of the methods and results here. We amplified nuclear regions of five protein-coding genes and one intron for 34 individuals from the S. scalaris group, including two individuals of the new species. We then used this molecular dataset to perform Bayes factor delimitation of species (BFD) in the coalescent-based species tree inference program *BEAST (Heled & Drummond 2010). Briefly, using the new BFD method in Grummer et al. (2014), we generated competing species delimitation models in which i) the individuals of the new species were constrained to belong to the S. brownorum species, and ii) the individuals of the new species were placed in their own lineage. The log e likelihood scores resulting from the fit of the molecular data to each model were compared using Bayes factors with the criterion that a lineage is distinct if the Bayes factor value of the best model was > 10 over other models. A NEW SPECIES OF BUNCHGRASS LIZARD (GENUS SCELOPORUS) Zootaxa 3790 (3) 2014 Magnolia Press 441

Principal components analysis. We took morphological measurements of 51 bunchgrass lizards, including 19 S. brownorum, three S. scalaris, 10 S. unicanthalis, five S. slevini, and 14 individuals of the new species (Appendix 1). These species were selected for comparison because they were geographically proximate to the new species and closely related (Grummer et al. 2014; Figs. 1 2). We also obtained data for S. chaneyi from Liner & Dixon (1992). Morphometric measurements were taken with either a ruler or digital calipers, and measurements were recorded to the nearest half-millimeter or hundredth of a millimeter, respectively. Snout-vent length was measured from the tip of the snout to the posterior portion of the cloacal opening. Head length was measured from the tip of the snout to the posterior edge of the interparietal. The length of the tibia was measured on the left leg from the top of the tibia to where the tibia meets the tarsi. Dorsal scales were counted from the posterior margin of the interparietal to the posterior level of the thighs. The number of scales around the middle of the body was counted halfway between the axial and groin regions. Ventral scales were counted from the incomplete gular fold to the anterior margin of the cloaca. Scale morphology and descriptions follow Smith (1939). We ran principal components analysis (PCA) on the complete morphological dataset to examine group membership and clustering. This dataset consisted of 49 individuals with complete morphological data (two damaged specimens were not used; Appendix I) for the following 24 characters: snout-vent length (SVL); head length; tibia length; entire hind limb length; the number of dorsals, midbody scales, ventrals, canthals, frontonasals, internasals, supralabials, infralabials, preoculars, loreals, lorilabials, frontoparietals, parietals bordering interparietal, scales bordering interparietal, scales between second pair of postmentals, scales between third pair of postmentals, and postnasals; and presence or absence of interparietal with posterior notch, scale in front of frontal, and scale behind frontal. PCA analyses were performed with the prcomp stats function in R on three groups: combined female and male, female, and male; grouping by sex allowed us to account for sexual dimorphism. We normalized and log 10 -transformed our data; however, the PCA results did not change from the original data matrix. We therefore only show results for the non-normalized, non-transformed dataset. Results Molecular species delimitation. Our final molecular dataset totaled 4,635 aligned base pairs (bp) and included six nuclear loci that ranged from 521 1,254 bp with 433 parsimony-informative sites. Species delimitation using the BFD approach provided decisive support for the species delimitation model with the individuals of the new species comprising their own lineage (Bayes factor value > 29). The phylogeny showing the phylogenetic placement of the new species in relation to other S. scalaris group members is shown in Figure 2. In addition to our quantitative coalescent-based delimitation, concatenation (Fig. 5 in Grummer et al. 2014) and individual gene tree analyses (supplemental file in Grummer et al. 2014) strongly placed the new species in clades distant from S. brownorum. Principal components analyses. We conducted PCA analyses with and without binary characters, and their inclusion did not affect our results so we used the full dataset of binary, discrete, and continuous characters in final analyses. Principal component 1 loaded strongly with SVL and hind limb length, whereas principal component 2 loaded strongly with the number of dorsal scales, number of scales around midbody, and number of ventral scales (Table 1). Because SVL and hind limb length were positively correlated, as were number of dorsal, midbody, and ventral scales with each other, we performed separate analyses without SVL, dorsal and midbody scales (6 permuted analyses), but our PCA results were not sensitive to these correlations (i.e., our PCA results did not differ with these different datasets). The first two and three principal components explained approximately 60% and 80% of the variance in the dataset, respectively. Plotting PC1 vs. PC2 across sexes revealed a distinct grouping of the new species from the type locality, whereas other individuals of the new species fell outside this tighter cluster (Fig. 3). However, all individuals of the new species were nested within the morphospace that enveloped S. brownorum, and also partially overlapped with S. slevini and S. unicanthalis. Analyses of females revealed a grouping of the new species, whereas the analysis of males alone showed similar results to the analysis including both sexes where the new species clustered by population (Fig. 3). 442 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON

FIGURE 3. Results of the principal components analyses when all individuals of Sceloporus scalaris group species were analyzed together (a), females only (b), and males only (c). A NEW SPECIES OF BUNCHGRASS LIZARD (GENUS SCELOPORUS) Zootaxa 3790 (3) 2014 Magnolia Press 443

Sceloporus aurantius sp. nov. Sceloporus scalaris (part): (McCranie & Wilson 2001): 20. Sceloporus scalaris (part): (Vázquez-Díaz & Quintero-Díaz 2005): 155. Sceloporus scalaris brownorum (part): Smith et al. 1997: 290. Sceloporus scalaris brownorum (part): Watkins-Colwell et al. 2006: 814.1. Sceloporus scalaris brownorum (part): Bryson et al. 2012: 448. Sceloporus scalaris brownorum (part): Grummer et al. 2014: 120. Holotype. MZFC 28392 (field number RWB 1042; Fig. 4). Adult female. Mexico: Aguascalientes: Municipio Calvillo, Los Alisos, Sierra del Laurel (N 21 43 32.2, W102 42 01.4 ; 2419 m). 20 July 2010. Robert W. Bryson, Jr. Paratypes. Thirteen specimens. Mexico: Aguascalientes: Same locality as the holotype. 20 July 2010. Robert W. Bryson, Jr., José Carlos Arenas-Monroy, and Michael Torocco. MZFC 25101 25106 (field numbers RWB 1019 1024). Four adult females, two adult males (Fig. 5). Ciénega [Sierra del Laurel] (N 21 45 0.0, W 102 43 01.2 ; 2370 m). 4 August 1979. Larry Wilson. USNM 346561 346564. Two adult females, two adult males. Jalisco: 1 mi NE Villa Hidalgo [foothills of the Sierra del Laurel]. 24 October 1950. KUH 29636. Juvenile male. Zacatecas: Ojo de Agua, 2.5 km NW Rancho Los Adobes (N 21 44 53.86, W 103 29 42.9 ; 2140 m). 27 April 2008. Iván T. Ahumada Carrillo. MZFC 24818. Adult male (Fig. 6). 3.4 km S La Estancia (N 21 41 44.2, W 103 28 56.1 ; 2228 m). 26 May 2008. Iván T. Ahumada Carrillo. MZFC 24831. Adult male. TABLE 1. Morphological characters of bunchgrass lizards in the Sceloporus scalaris group used in the principal components (PC) analyses along with their respective PC loadings. Character PC1 PC2 PC3 Snout-vent length 0.8883 0.0728-0.0544 Head length 0.1337-0.0005-0.0164 Tibia length 0.1707-0.0588 0.0667 Hind limb length 0.3890-0.1004 0.2463 Number of dorsals 0.0491 0.4934-0.4628 Number of mid-body scales -0.0101 0.4498-0.4574 Number of ventrals -0.0410 0.7161 0.6158 Number of canthals 0.0303 0.0274 0.0426 Number of frontonasals 0.0010-0.0281-0.0084 Number of internasals -0.0449 0.1194 0.2153 Number of supralabials 0.0046 0.0032-0.0136 Number of infralabials -0.0202 0.0407-0.0037 Number of preoculars 0.0006-0.0296 0.0041 Number of loreals -0.0012-0.0182 0.0000 Number of lorilabials -0.0346-0.0069 0.1055 Number of frontoparietals 0.0232 0.0208 0.0409 Number of parietals -0.0113-0.0138-0.0081 Number of scales bordering interparietal -0.0402-0.0001 0.1879 Number of scales in 2nd row of postmentals -0.0114-0.0263-0.1204 Number of scales in 3rd row of postmentals -0.0314 0.0385-0.1289 Number of postnasals contacting nasal scale 0.0007-0.0129 0.0217 Posterior notch on interparietal 0.0049 0.0152 0.0181 Scale anterior to frontal -0.0182 0.0267 0.0194 Scale posterior to frontal 0.0075 0.0039 0.0038 444 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON

FIGURE 4. Holotype specimen of Sceloporus aurantius sp. nov. (MZFC 28392) in dorsal (a), ventral (b), and in-life (c) views. A NEW SPECIES OF BUNCHGRASS LIZARD (GENUS SCELOPORUS) Zootaxa 3790 (3) 2014 Magnolia Press 445

FIGURE 5. Dorsal pattern variation within the paratype series of Sceloporus aurantius sp. nov. from the Sierra del Laurel, Aguascalientes: a) MZFC 25102 (female), b) MZFC 25103 (female), c) MZFC 25106 (male), and d) MZFC 25101 (male). Diagnosis. Sceloporus aurantius sp. nov. belongs to the S. scalaris species group, sharing with other species in that group the following characters: parallel lateral scale rows (except in S. goldmani), femoral pore series in contact or separated by no more than two scales, females with smooth preanal scales, and males with lateral abdominal color patches (Smith 1939; Smith et al. 1997; Watkins-Cowell et al. 2006). Sceloporus aurantius sp. nov. differs from all S. scalaris group species except S. chaneyi by the lack of blue belly bars in adult males. Sceloporus aurantius sp. nov. differs from S. chaneyi in adult size (mean snout-to-vent length 49.8 mm vs. 45.7 mm), number of dorsal scales (mean of 39.2 vs. 42.3), number of scales around midbody (mean of 37.9 vs. 40.4), and presence of an un-patterned morph (absent in S. chaneyi). Although not a diagnostic character state, Sceloporus aurantius sp. nov. further differs from S. chaneyi, and all other species in the S. scalaris species group, by unique phylogenetic position revealed through species delimitation (Grummer et al. 2014; Fig. 2). Description of holotype. Adult female (Fig. 4). SVL 55 mm, 117 mm with tail. Head length 11.05 mm. Tibia length 10 mm. Entire hind limb length (including 4 th toe) of 24 mm. Forelimb length 13 mm. Dorsal head scales keeled and rugose. Five internasals of irregular shape. Canthals 2 2 (right left). Loreals 1 1. Supralabials 5 5. Infralabials 6 5. Postnasals 2 2, irregular. Preoculars 1 1 with a strong transverse keel on posterior margin. Five frontonasals, keeled. Two prefrontals, rugose and keeled with medial contact posteriorly, divided by a frontonasal anteriorly. One frontal transversely divided, rugose, with two keels on lateral margins. Interparietal coronate with posterior notch. Frontoparietals 2 2. Parietals 2 2, rugose. Two complete lorilabial rows. Dorsal scales keeled, acuminate, smooth (not serrate). Thirty-nine dorsal scales. Parallel lateral scale rows on body. Scales around midbody 38. Ventral scales rounded with posterior notch. Pale vertebral stripe two scales wide. Two pale dorsolateral stripes approximately ½ scale wide, interspersed with dark flecks. Vertebral and dorsolateral stripes separated by three scale rows. Two pale lateral stripes ½ scale 446 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON

wide, separated from dorsolateral stripes by two scale rows. Chevrons in four rows between each pair of dorsal stripes; 7 between left lateral and dorsolateral stripes, 12 between left dorsolateral and vertebral stripes, 12 between vertebral and right dorsolateral line, 8 between right dorsolateral and lateral stripes. Chevrons are dark with scales posterior margins pale. Dorsolateral and ventral surfaces pale with minute dark flecks throughout. Gular region lacking distinct markings. Color in preservative. Dorsal and lateral portions of head brown with white between ocular and opercular openings; white loreal scales. Underside of head is white with small black flecks. Two white dorsolateral lines (~1 scale wide) and a broad (~3 scales wide) light gray vertebral stripe fading into base of tail. Numerous black chevrons with white posterior margins, between vertebral and dorsolateral stripes. Scales between chevrons are brown. A single white line (~1 scale wide) extends from posterior portion of operculum to inguinal area where the femur joins the body on the lateral portion of the belly, separated from dorsolateral line by black chevrons with brown scales between. Front and hind limbs are brown with black, grey, and white scales scattered throughout. Proximal dorsal portion of tail with black and grey scales on a grey/brown background. Distal portion of tail is brown. Undersides of limbs, venter, and tail are white with sparsely distributed small black flecks. Chin and throat without distinct black or grey streaks or bars. Color in life. Head: brown/rust on dorsal portion, grey-brown on sides in front of and below eyes. Dorsum with two cream-colored dorsolateral lines and dark grey vertebral stripe. Black chevrons in between vertebral and dorsolateral lines, with posterior margins of dark scales containing white margins. Portions between chevrons are rust/brick red. On each side of the belly, a white line (~1 scale wide) extends from head to femur as described above. Lateral scales between white lateral line and ventral scales are light red/brown. Front limbs grey with a black shoulder spot. Hind limbs grey with faint black bars lined with white on posterior edges. Proximal dorsal portion of tail with black triangles; distal dorsal portion brown. FIGURE 6. Male paratype Sceloporus aurantius sp. nov. (MZFC 24818) from southern Zacatecas. Morphometric variation. Adults only. Includes 7 females and 6 males. Snout-vent length 48 55 mm (x =50.85; SD=3.41). Head length (snout to posterior edge of interparietal) 9.6 11.35 mm (10.68 mm; 0.55). Tibia A NEW SPECIES OF BUNCHGRASS LIZARD (GENUS SCELOPORUS) Zootaxa 3790 (3) 2014 Magnolia Press 447

length (left side) 9 10.5 mm (9.46 mm; 0.52). Entire hind limb length (including fourth toe) 22 26.5 mm (23.46 mm; 2.08). Scalation variation. Includes 7 females and 7 males. Dorsal scales range 37 43 (x =39.21; SD=1.72). Scales around midbody 35 42 (37.93; 1.82). Ventral scales 35 46 (42.21; 2.81). Canthals 2 2 (LR; 14/14). Frontonasals 3 4 (3.36; 0.74). Supralabials 5 5 (LR; 12/14), 6 5 (1/14), 6 6 (1/14). Infralabials 5 6 (1/14), 6 6 (5/14), 7 6 (2/ 14), 7 7 (6/14). Preoculars (missing data from one damaged specimen, USNM 346564) 1 1 (10/13), 1 2 (1/13), 2 2 (2/13). Loreals (missing data from USNM 346564) 1 1 (1/13), 1 2 (1/13), 2 1 (1/13), 2 2 (6/13), 2 3 (2/13), 3 2 (1/13), 3 1 (1/13). Frontoparietals 2 4 (2.64; 0.84). Coloration variation. In life, lateral edge of body and venter with orange streak in males, becoming less distinct at midbody towards back leg (Figs. 5 6). A male paratype (USNM 346561) was elsewhere described in life as having an orange-colored side with cream spotting below the lateral line (McCranie & Wilson 2001). This orange streak is not apparent in preservative. A pattern-less morph occurred in both males and females. One male (MZFC 24831) had some dark mottling on chin. Etymology. The specific epithet is formed by the Latin adjective aurantius, which means orange colored, in reference to the orange dorsolateral streak of males. As common names we suggest Southern Occidental Bunchgrass Lizard (English) and Lagartija de Pastizal Sur Occidental (Spanish). Distribution. Known from the oak forests of the Sierra del Laurel in southwestern Aguascalientes and southern Zacatecas (Fig. 1). However, we suspect that S. aurantius sp. nov. may be more widespread across the southern sky islands of the Sierra Madre Occidental. Unfortunately, because females are difficult to distinguish from other regional species of bunchgrass lizard, we could not confidentially ascertain whether the female specimens from this region (LSUMZ 35078, 35108; and UTEP 6504 6506) are S. brownorum (as currently designated in Smith et al. 1997) or S. aurantius sp. nov. Natural history. Most of the type series (MZFC 25101 25106, 28392) were collected on 20 July 2010 throughout the day in patches of bunchgrass within oak forest (Fig. 7). Four females contained well-developed eggs. The two specimens from southern Zacatecas were collected in oak forest. FIGURE 7. Habitat at the type locality for Sceloporus aurantius sp. nov., Los Alisos, Sierra del Laurel, Aguascalientes. 448 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON

Discussion Although S. aurantius sp. nov. is distinct based on traditional phylogenetic methods and Bayes factor delimitation of species (Grummer et al. 2014), our PCA analyses of traditional morphological characters used to describe previous S. scalaris group taxa (e.g., Smith 1937; Smith et al. 1997) revealed strong morphological overlap between S. aurantius sp. nov. and other recognized species (Fig. 3). In fact, all species that were measured overlapped in PCA analyses, a finding that supports previous claims that these characters are highly variable and probably of limited utility in the S. scalaris species group (Thomas & Dixon 1976). The only morphological character that we are aware of to distinguish S. aurantius sp. nov. from other S. scalaris group taxa is the lack of blue belly patches and presence of an orange dorsolateral streak in male S. aurantius sp. nov. Male ventral coloration is critical for sexual selection and species-specific mate recognition (e.g., Wiens 1999) and so this morphological character is probably still important in diagnosing species. Distinguishing between S. aurantius sp. nov. and regional species of bunchgrass lizards based only on male ventral coloration makes discernment of female S. aurantius sp. nov. from geographically proximate species such as S. brownorum difficult. However, the predominantly oak forest habitat at the type locality of S. aurantius sp. nov. (Fig. 7) is different from the Madrean pine-oak habitat of S. brownorum (Vázquez-Díaz & Quintero-Díaz 2005) and may be an indicator of ecological differences. Additional fieldwork and geographic sampling is needed to identify the full geographic range of S. aurantius sp. nov., perhaps in concert with DNA barcoding to help distinguish females from adjacent S. scalaris group species. Acknowledgements We thank the following museums and their personnel for the loan of specimens used in this paper: California Academy of Sciences (CAS), Field Museum of Natural History (FMNH), Kansas University (KUH), Museum of Vertebrate Zoology (MVZ), Museo de Zoología Alfonso L. Herrera, Facultad de Ciencias, Universidad Nacional Autónoma de México (MZFC), University of Michigan (UMMZ), Smithsonian (USNM), and University of Texas at El Paso (UTEP). We also thank J.C. Arenas-Monroy and M. Torocco for assistance in the field, and to M. Hedin for the use of his camera to photograph the holotype. Permits to collect in Mexico were issued by SEMARNAT to RWB, the late F. Mendoza-Quijano, and the MZFC. We also thank I.W. Caviedes, C. Franklin, O. Flores-Villela, J. Jones, A. Nieto-Montes, E. Pérez-Ramos, G. Quintero-Diaz, T. Reeder, B.R. Riddle and C. Spencer for additional support. Color photo in Fig. 6 graciously provided by I.T. Ahumada-Carrillo. This paper is based in part upon work supported by the National Science Foundation grants DEB- 1257785 and DEB- 1258205. References Benabib, M., Kjer, K.M. & Sites, J.W. Jr. (1997) Mitochondrial DNA sequence-based phylogeny and the evolution of viviparity in the Sceloporus scalaris group (Reptilia, Squamata). Evolution, 51, 1262 1275. http://dx.doi.org/10.2307/2411055 Bryson, R.W., García-Vázquez, U.O. & Riddle, B.R. (2012) Relative roles of Neogene vicariance and Quaternary climate change on the historical diversification of bunchgrass lizards (Sceloporus scalaris group) in Mexico. Molecular Phylogenetics and Evolution, 62, 447 457. http://dx.doi.org/10.1016/j.ympev.2011.10.014 Grummer, J.A., Bryson, R.W. & Reeder, T.R. (2014) Species delimitation using Bayes factors: simulations and application to the Sceloporus scalaris species group (Squamata: Phrynosomatidae). Systematic Biology, 63 (2), 119 133. Heled, J. & Drummond, A.J. (2010) Bayesian Inference of Species Trees from Multilocus Data. Molecular Biology and Evolution, 27, 570 580. http://dx.doi.org/10.1093/molbev/msp274 Liner, E.A. & Dixon, J.R. (1992) A new species of the Sceloporus scalaris group from Cerro Pena Nevada, Nuevo Leon, Mexico (Sauria: Iguanidae). The Texas Journal of Science, 44, 421-427. McCranie, J.R. & Wilson, L.D. (2001) The herpetofauna of the Mexican State of Aguascalientes. Courier Forschungsinstitut Senckenberg, 230, 1 57. Mink, D.G. & Sites, J.W. (1996) Species limits, phylogenetic relationships, and origins of viviparity in the Scalaris complex of the lizard genus Sceloporus (Phrynosomatidae: Sauria). Herpetologica, 52, 551 571. A NEW SPECIES OF BUNCHGRASS LIZARD (GENUS SCELOPORUS) Zootaxa 3790 (3) 2014 Magnolia Press 449

Poglayen, I. & Smith, H.M. (1958) Noteworthy Herptiles from Mexico. Herpetologica, 14, 11 15. Smith, H.M. (1937) A synopsis of the scalaris group of the lizard genus Sceloporus. Occasional Papers of the Museum of Zoology, 361, 1 8. Smith, H.M. (1939) The Mexican and Central American Lizards of the Genus Sceloporus. Zoological Series: Field Museum of Natural History, 26, 1 427. Smith, H.M. & Hall, W.P. (1974) Contributions to the concepts of reproductive cycles and the sytematics of the scalaris group of the lizard genus Sceloporus. Great Basin Naturalist, 34, 97 104. Smith, H.M., Watkins-Colwell, G.J., Lemos-Espinal, J.A. & Chiszar, D. (1997) A new subspecies of the lizard Sceloporus scalaris (Reptilia: Sauria: Phrynosomatidae) from the Sierra Madre Occidental of Mexico. Southwestern Association of Naturalists, 42, 290 301. Thomas, R.A. & Dixon, J.R. (1976) A re-evaluation of the Sceloporus scalaris group (Sauria: Iguanidae). Southwestern Association of Naturalists, 20, 523 536. http://dx.doi.org/10.2307/3669869 Vázquez-Díaz, J. & Quintero-Díaz, G.E. (2005) Anfibios y Reptiles de Aguascalientes. CONABIO, CIEMA, 318 pp. Watkins-Colwell, G.J., Smith, H.M. & Chiszar, D. (1996) Geographic distribution. Sceloporus chaneyi. Herpetological Review, 27 (3), 153. Watkins-Colwell, G.J., Smith, H.M. & Chiszar, D. (2006) Sceloporus scalaris Wiegmann. Catalogue of American Amphibians and Reptiles, 814.1 814.10. Wiens, J.J. (1999) Phylogenetic evidence for multiple losses of a sexually selected character in phrynosomatid lizards. Proceedings of the Royal Society of London, Series B: Biological Sciences, 266 (1428), 1529 1535. APPENDIX I. Specimens examined. Asterisks denote two damaged specimens not used in principal components analyses. Sceloporus brownorum. Mexico: Aguascalientes: Sierra Fria (LSUMZ 35027, 35028, 35099; UMMZ 110879, 110893, 113650; USNM 346560). Granja Huentepec (CAS 19470*). Durango: El Salto (CAS 91854; MVZ 76550). Zacatecas: Chalchihuites (CAS 95910 95918). Sceloporus aurantius sp. nov. Mexico: Aguascalientes: Municipio Calvillo, Los Alisos, Sierra del Laurel (MZFC 25101 25106, 28392). Ciénega [Sierra del Laurel] (USNM 346561 346563, 346564*). Jalisco: 1 mi NE Villa Hidalgo [foothills of the Sierra del Laurel] (KUH 29636). Zacatecas: Ojo de Agua, 2.5 km NW Rancho Los Adobes (MZFC 24818). 3.4 km S La Estancia (MZFC 24831). Sceloporus scalaris. Mexico: Guanajuato: Sierra Cualtraba (MZFC 25107 25108). Jalisco: 5 mi N of Cuautla (KUH 93480). Sceloporus slevini. U.S.A.: Arizona: Las Cienegas grassland, NE Sonoita (UTA R 60720). Chiricahua Mountains (UTA R 60716 60718). Santa Rita Mountains (UTA R 60719). Sceloporus unicanthalis. Mexico: Durango: ca. 21 km S & 12 km W Teneraca (UTEP 7408 7410). near Huazamota, between Huazamota and Santa Teresa, Nayarit (USNM 46626). Jalisco: 3 mi WSW Mazamitla (KUH 37732 37733). 4 mi W Mazamitla (KUH 29795). Magdalena (FMNH 32009). Nayarit: 37.1 mi E Ixtlan del Rio on Mexico Hwy 15 (MVZ 72185) ca. 1 km S & 27 km E Huajicori (UTEP 7417).. 450 Zootaxa 3790 (3) 2014 Magnolia Press GRUMMER & BRYSON