Zootaxa 2488: 22–38 (2010) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2010 · Magnolia Press ISSN 1175-5334 (online edition) A new cryptic species of Acanthosaura Gray, 1831 (Squamata: Agamidae) from Thailand and Cambodia PERRY L. WOOD JR1,6, L. LEE GRISMER2, JESSE L. GRISMER1, THY NEANG3, THOU CHAV4, & JERMEY HOLDEN5 1Department of Biology, Villanova University, Villanova, PA 19085, USA. E-mail: [email protected], [email protected] 2Department of Biology, La Sierra University, Riverside, CA 92515-824, USA E-mail: [email protected] 3General Department of Nature Conservation and Protection (DNCP), Ministry of Environment, Phnom Penh, Cambodia. E-mail: [email protected] 4Department of Environment, Pursat Penh, Cambodia 567 High Street Meppershall, Beds, SG17 5LX, UK. E-mail: [email protected] 6Corresponding author. E-mail: [email protected] Abstract A new species of Acanthosaura (Gray 1831), A. cardamomensis sp. nov. from eastern Thailand and western Cambodia is described based on having a combination of unique morphological characteristics. It most closely resembles A. crucigera but differs in having significantly longer postorbital spines, occipital spines, nuchal spines, and dorsal spines; more scales between the fifth canthals; longer maximum dorsal scale length; longer maximum nuchal scale length; a significantly smaller diastema between the nuchal and dorsal crest spines; and significantly more supralabials. Mitochondrial DNA was used to calculate percent sequence divergence between samples of A. crucigera from southern Myanmar and western Thailand and samples of A. cardamomensis sp. nov. from eastern Thailand and western Cambodia. The uncorrected pairwise sequence divergence between populations of A. cardamomensis ranged from 1.2– 3.1% and the range between populations of A. crucigera was 3.8%. The percent sequence divergence between A. cardamomensis sp. nov. and A. crucigera ranged between 10.0–14.6%. Key words: Acanthosaura, armata, cardamomensis, crucigera, Cardamom Mountains Introduction Species of the Southeast Asian agamid genus Acanthosaura (Gray 1831) are diurnal, arboreal, insectivores ranging in elevation from sea level to 1450 m a.s.l. (Ananjeva 2008). Currently, the genus contains eight species ranging from northeastern India, east through Myanmar, Thailand, Cambodia, Laos, Vietnam, southern China (including Hainan island), and southward through the Malay Peninsula and adjacent archipelagos (Grismer et al. 2006) to Sumatra, and the Anambas and Natunas Archipelagos (Grismer et al. 2008a,b; Leong et al. 2002; Taylor 1963; Manthey & Grossmann 1997; Manthey 2008). Recent molecular investigations of the relationships within Acanthosaura have established that some of the wide-ranging species were composed of multiple species (Kalybina-Hauf et al. 2004; Ananjeva et al. 2008). Acanthosaura crucigera is one of these wide-ranging species, which extends from Myanmar east through Thailand, Cambodia, and southward to Northern Peninsular Malaysia (Boulenger 1912; Grismer et al. 2006b; Manthey & Grossmann 1997; Manthey 2008; Pauwels et al. 2003; Taylor 1963). Wood et al. (2009) demonstrated that the montane population from Bukit Larut, Perak in Peninsular Malaysia referred to as of A. crucigera (Boulenger 1912; Manthey 2008) was a different species, A. bintangensis. Within Cambodia, there are three species of Acanthosaura: A. capra (Günther 1861), A. coronata (Günther 1861) and A. crucigera (Boulenger 1885). Acanthosaura capra and A. coronata are found in hilly 22 Accepted by S. Carranza: 20 Apr. 2010; published: 31 May 2010 eastern Cambodia (Stuart et al. 2006) and A. crucigera occurs in the Cardamom Mountains in western Cambodia (Grismer et al. 2008; Stuart & Emmett 2006). Boulenger (1885) considered a male specimen collected by Henri Mouhot in the mid nineteenth century from “Chartaboum” (= Chanthaburi Province) from the Thai Cardamom Mountains (BMNH 61.4.12.43) southeastern Thailand, as A. armata. Smith (1935) was the first to report A. crucigera from the southeastern region of the Cardamom Mountains and subsequent surveys throughout the Cardamom Mountains reported additional populations (Stuart & Emmett 2006; Daltry & Chheang 2000; Grismer et al. 2007, 2008a,b; Daltry & Traehdt 2003; Chuaynken et al. 2004). Stuart and Emmett (2006) commented on the differences in Boulenger’s and Smith’s taxonomic opinions and determined that they all resembled the Cambodian specimens of A. crucigera. Genetic and morphological analyses of these lizards from eastern Thailand and Cambodia, previously ascribed to A. crucigera and A. armata have revealed they cannot be ascribed to any known species of Acanthosaura and are described herein as new. Materials and methods Specimens were collected by hand or blow pipe during all hours of the day from Phnom Aural (4-10 August 2005), Phnom Samkos (4-13 August 2006), and Phnom Dalai (4-10 July 2009). Photographs were taken to document color pattern in life prior to euthanization. Liver samples taken were stored in 100% ethanol and lizards were fixed in 10% formalin and later transferred to 70% ethanol. Fifty-two morphological characters were analyzed and taken from museum specimens (Appendix) and the literature (Hardwicke & Gray 1827; Gray 1831, 1845; Orlov et al. 2006; Günther 1861, 1864; Boulenger 1885, 1912; Smith 1935; Taylor 1963; Manthey & Grossmann 1997; Stuart & Emmett 2006; Stuart et al. 2006; Ananjeva et al. 2008; Wood et al. 2009) from all currently recognized species of Acanthosaura. Measurements were taken on the type series to the nearest 0.1 mm with Mitutoyo digital calipers under a Nikon SMZ 1000 dissecting microscope. All measurements were made on the left side of the body where applicable (fide Wood et al. 2009). Characters examined were: SVL—snout vent length, measured from the tip of the snout to the tip of the vent; TL—tail length, measured from the posterior margin of the vent to the tip of the tail; HL—head length, measured from posterior edge of the rectis of the jaw to the tip of the snout; HW—maximum head width, the width at the level of the tympanum; HD—maximum head height, measured across the parietal region; SL—snout length, measured from the anterior edge of the orbit to the tip of the snout; MW—mental width; MH—mental height; RW—rostral width; RH—rostral height; ORBIT—eye diameter, measured from the posterior to the anterior edge of the eye; TD—tympanum diameter, measured horizontally from the anterior to the posterior border of the tympanum; OS—length of the occipital spine, measured from the base to the tip; SUPRAL—number of supralabials; INFRAL—number of infralabials; DIASN—number of scales in the vertebral crest scale diastema counted from the posterior end of the nuchal crest to the anterior end of the dorsal crest; VENT— number of ventral scales counted at the midline from the anterior edge of the shoulders to the edge of the vent; FI—number of subdigital lamellae on the fourth finger; TO—subdigital lamellae on the fourth toe; NSSOS, number of scales surrounding the occipital spine; CS—number of canthus-rostralis-supracilliary scales, counted from the nasal scale to the posterior end of the ridge at the posterior margin of the orbit; NS—number of scales between the nasals; PM—number of postmental scales bordering the mental; TN—scales absent on tympanum (0) or present (1); YAS— presence (1) or absence (0) of a Y-shaped arrangement of enlarged scales on the snout; ND— presence (1) or absence (0) of a black, diamond shaped, nuchal collar; BEP—presence or absence of a black eye patch; ESBO, presence or absence of elliptical scales below the orbit (Table 1). Institutional abbreviations are BMNH, Natural History Museum, London, England; CUMZR, Chulalongkorn University Museum of Zoological Records, Bangkok, Thailand; THNHM Thailand Natural History Museum, Pathum Thani, Thailand; FMNH, Field Museum of Natural History, Chicago, Illinois, USA; LSUHC, La Sierra University Herpetological Collection, La Sierra University, Riverside, California, USA; UKMHC, Universiti Kebangsaan Malaysia Herpetological Collection, Bangi, Selangor, West Malaysia and ZRC, Zoological Reference Collection at the Raffles Museum of Biodiversity at the National University of Singapore. A NEW SPECIES OF ACANTHOSAURA Zootaxa 2488 © 2010 Magnolia Press · 23 Statistical analyses were used to test for significant differences in means. All data were analyzed using PASW statistics 17.0 (SPSS Inc., Chicago, IL). Kolmogorov-Smirnov and Shapiro-Wilk tests were used to test for normal distributions between the variables. When distributions were normal a two-sample t-test was used to test for significant differences between the means of different groups. Levene’s test for equal variances was also employed. When distributions were not normal, the nonparametric Mann-Whitney U test was used to test for significant differences between different means. Molecular data was collected from 12 specimens of Acanthosaura crucigera from Thailand and Cambodia to determine the percent sequence divergence between the different populations. For all the taxa used in the genetic study GenBank accession numbers can be found in the (Appendix). Genomic DNA was extracted from liver or muscle tissue that were preserved in 95–100% ethanol following Qiagen DNeasy tissue kit (Valencia, CA, USA). We used two primers, METF6 (L4437a; 5′–AAG CTT TCG GGC CCA TAC C– 3′) from Macey et al. (1997) and a primer new to this paper ACANTHND2.833.R1 (5′– AGG GAG GTT