Acanthosaura bintangensis

Bukit Larut Mountain Horned Agamid Acanthosaura crucigera. Boulenger, G. A. 1912: 69. A Vertebrate Fauna of the Malay Peninsula from the Isthmus of Kra to Singapore including the adjacent islands. Reptilia and Batrachia. Taylor and Francis, London.

sp. nov sp. nov n = 3 n = 3 n = 26 n = 0 n = 2 n = 10 n = 1 n = 3 SVL 83.9 – 142 91.8 – 118.4 84.28 – 140 94 – 137.9 73 – 90 71 – 100.21 106.7 – 158 76.45 – 101.1 TL 112.8 – 206 136 – 174 105 – 186.9 133.6 – 182.1 115.5 – 115.8 95.6 – 162 171 – 287 130.6 – 144.1 to be continued. Description of the Holotype. (Fig. 2). Adult male, SVL 114.8 mm, TL 166.0 mm. Head short (HL / SVL 19 %), some what narrow (HW / SVL 17 %) moderately tall (HD / HL 0.85), triangular in dorsal and lateral profile; moderate snout length (SL / HL 46 % mm), interorbital and frontal regions and rostrum wide (RW / RH 229 %), steeply sloping anteriorly; canthus rostralis prominent, forming a large projecting shelf extending above eye, composed of 14 enlarged scales; shelf terminates with a notch anterior to the postorbital spine; rostral moderate in size, rectangular, bordered laterally by first supralabials and posteriorly by seven smaller scales; nasals concave, surrounded by one prenasal and three postnasal scales; eight scales between nasal scales; supranasals somewhat elongate; enlarged scales above orbit weakly keeled; an enlarged row of keeled scales below orbit extending from anterior margin of eye to middle of eye with two enlarged elliptical keeled scales, one near the anterior edge of orbit and another directly below orbit, with three smaller keeled scales in between them; eye large (EYE / HL 30 %); interorbital, frontal, and prefrontal scales keeled and smaller than enlarged row of keeled scales below the orbit; three enlarged, keeled, azygous prefrontals arranged in a Yshaped pattern; scales of occiput flat to weakly keeled; no enlarged parietal eyespot; short cylindrical epidermal spine above posterior margin of eye; occipital spine surrounded by seven enlarged keeled scales; suborbitals enlarged, keeled, extending in single row of six scales from below posterior margin of eye to anterior margin of tympanum, increasing in size posteriorly, terminal scale spine-like; elongate cylindrical epidermal spine on lateral margin of nape surrounded by a rosette of seven smaller spines; tympanum exposed, oblong, taller than wide, surrounded by small conical scales; supralabials 12, rectangular, not decreasing in size posteriorly; mental square above becoming triangular below, much larger than adjacent infralabials; two postmentals similar in size, five scales contacting mental; chinshields enlarged, extending posteriorly past angle of jaw, separated from infralabials by one scale row anteriorly and three at angle of jaw; infralabials 12, rectangular, scales in center of series largest; gulars sharply keeled and spinose with no enlarged midventral row; dewlap extensible; gular pouch large; nuchal crest with a diastema 11 scales at base of nape; nuchal crest composed of eight elongate, lancolate scales bordered on each side by two rows of enlarged, spinose scales; dorsal body crest present, extending from posterior margin of diastema onto base of tail, vertebral crest composed of enlarged epidermal, laterally compressed, spinose scales, bordered by a single row of slightly smaller paravertebral squarish, spinose scales; vertebral crest tapers slightly to base of tail then fades approximately midway down tail. Body moderately developed, triangular in cross-section; dorsal scales small with medially projecting spines; larger randomly arranged scale clusters among dorsals; scales of pectoral region and abdomen larger than dorsals, keeled, spinose, arranged in semi-transverse rows; keeled scales anterior to vent not enlarged; limbs relatively long; dorsal and ventral scales of forelimbs keeled, spinose, and nearly same size; five digits on manus; subdigital scales keeled; scales of hind limbs keeled and spinose; postfemoral scales small, interspersed with larger spinose scales; five digits on pes; subdigital scales keeled; subdigital lamellae under fourth finger 23; subdigital lamellae under fourth toe 25; tail 144 % of SVL, covered with keeled spinose scales; keels on subcaudals posteriorly directed, same size as keels of other caudal scales; base of tail in males nearly twice as wide as that in females. Coloration in life. (Fig. 2). Dorsal surface of head, body and limbs straw colored, sides and top of head immaculate straw colored; dark eye patch restricted to orbital region and not extending onto side of head; iris red; black collar complete dorsally; posterior gular region solid black, making contact with collar; yellow medial stripe on dewlap present, extending from base of gular region to the anterior edge of gular pouch; large yellow spots edged in blackish-brown arranged on body and base of tail, spots are larger towards the nape and decrease in size towards the base of the tail; forelimbs straw colored; faint spotting on hind limbs; tail faintly banded anteriorly, posterior 2 / 3 nearly solid black; underside of limbs and belly beige; pectoral region orangish. Variation. (Fig. 3). The paratypes resemble the holotype in most aspects of morphology except that the female FMNH 143140 has larger and fewer spots on the dorsum, black color in the gular region is not as prominent, medial yellow stripe on the dewlap is not as distinct, and tail bands are more prominent. The juvenile male ZRC 2.309 has smaller but more numerous spots on the dorsum, a faded black color and a lighter colored tail with prominent bands. Scalation and morphological variation is presented in Table 2. Sex ZRC 2.6804 Holotype Male FMNH 143140 Paratype Female ZRC 2.309 Paratype Juvenile SVL 114.8 142 83.9 TL 166 206 112.8 HL 22.4 25.4 16.9 HW 20 23.6 17.1 HD 19.2 20 15 SL 10.5 11.3 7.9 EYE 6.9 5.1 5.5 TD 3 2.5 2.7 TN 1 1 1 PS 4.2 1.9 2.4 NS 4.7 4.4 1.3 NSL 1.9 2.3 1.5 DS 1.8 2.2 / DSL 1.7 2.6 1.2 WN 1.6 2.1 1.7 WDS 2 2.4 1.7 DIAS 5 7.9 5.5 DIASN 11 15 13 DIAS / SVL 0.04 0.06 0.06 FOREL 56.4 61.5 33.9 HINDL 57.2 68.6 43.3 SUPRAL 12 12 12 INFRAL 12 12 11 VENT 53 55 51 FI 23 23 23 TO 26 28 27 TL / SVL 1.4 1.4 1.3 OS 2.4 2.6 1.2 NSSOS 7 7 6 CS 14 15 15 RW 3.9 5.3 3.6 RH 1.7 1.8 2 RS 9 7 9 to be continued.

Diagnosis. Maximum SVL 114.8 mm of males, maximum SVL of females 142.0 mm; head triangular, snout short (SL / HL 0.44 – 0.46); eye moderate to large (EYE / HL 0.20 – 0.32); two elliptical keeled scales below the orbit; 14 or 15 scales on canthus rostralis-supraorbital ridge; large rectangular rostral scale; single short cylindrical spine above posterior margin of eye surrounded by a rosette of six or seven smaller keeled scales at base; spine on occiput between tympanum and nuchal crest present; tympanum naked, oblong, taller than wide; dewlap present in males and females; body triangular in cross section; scales of flanks intermixed with randomly arranged clusters of larger keeled scales; nuchal crest present; 11 – 15 scales in nuchal diastema; vertebral crest composed of enlarged, pointed scales beginning at shoulder region and tapering to a series of enlarged keeled scales on anterior portion of tail; tail 1.3 – 1.5 % of SVL; black collar present; posterior 2 / 3 of tail black to dark reddish brown; yellow spots on body encircled with black or brown (Fig. 2); medial yellow stripe in black gular region (Table 1). bintangensis titwangsaensis armata capra coronata crucigera nataliae lepidogaster

Distribution. Acanthosaura bintangensis is known only from the montane areas of Bukit Larut, Perak in the Banjaran Bintang, Peninsular Malaysia above 1,200 m in elevation. Given that this mountain range extends into southern Thailand and other montane endemics restricted to this range extends across the Thai- Malaysian border (Boulenger 1903; Flower 1896, 1899; Grismer et al. 2008), it is likely that A. bintangensis will be found further to the north as well. Natural history. Acanthosaura bintangensis is a montane species found in hill top dipterocarp forests ranging no lower than 1,200 m in elevation. The holotype was found during the day on the side of a small tree approximately 0.2 m in diameter in dense undergrowth approximately 1 – 2 m above the forest floor (Fig. 4) in an area where the immediate terrain is level but adjacent to hilly areas. Like other species of Acanthosaura, this species probably forages on the ground for food, digging through the soil (Taylor 1963). We hypothesize this based on soil fragments found on the labial scales and within the external nares of specimens. A gravid female was collected during August (FMNH 143140).

Etymology. This specific epithet bintangensis refers to the mountain range, Banjaran Bintang, to which this species appears to be restricted.

Holotype. Adult male (ZRC 2.6804) collected on 18 June 2008 by Jesse L. Grismer, L. Lee Grismer, Perry L. Wood Jr., at 1140 h at 1351 m a. s. l. from Bukit Larut, Perak, Peninsular Malaysia (04 º 51.446 ' N; 100 º 48.455 ' E). Paratypes. ZRC 2.309; juvenile male from Bukit Larut, Perak, Peninsular Malaysia. FMNH 143140; gravid female from Bukit Larut, Tuping, Perak, Peninsular Malaysia 4700 ′ (1,432 m) collected by Lim Boo Liat on 4 August 1959.