Acanthosaura tongbiguanensis , Liu, Shuo & Rao, Dingqi, 2019

Liu, Shuo & Rao, Dingqi, 2019, A new species of the genus Acanthosaura from Yunnan, China (Squamata, Agamidae), ZooKeys 888, pp. 105-132: 105

publication ID

http://dx.doi.org/10.3897/zookeys.888.38491

publication LSID

lsid:zoobank.org:pub:C454358A-DB07-4BE8-A22A-7B98CE3E6CF9

persistent identifier

http://treatment.plazi.org/id/9927F7C3-7913-5D3F-86F5-DC7B247FB931

treatment provided by

ZooKeys by Pensoft

scientific name

Acanthosaura tongbiguanensis
status

sp. nov.

Acanthosaura tongbiguanensis  sp. nov. Figures 3View Figure 3, 4View Figure 4, 5View Figure 5, 6View Figure 6, 10View Figure 10

Acanthosaura lepidogaster  : Zhao et al. 1999: 82-85.

Acanthosaura lepidogaster  : Yang and Rao 2008: 186-187.

Type material.

Holotype. KIZL201804, an adult male, 22:18 02 Sept 2018, leg. Shuo Liu, Tongbiguan Township (24°36 ’51.24” N, 97°35 ’1.88” E, 1170.24 m elevation), Yingjiang County, Dehong Autonomous Prefecture, Yunnan, China.

Paratypes. KIZL201801, an adult male, 22:53 01 Sept 2018, leg. Shuo Liu, same locality as holotype; KIZL201802 and KIZL201803, two juveniles, 21:00-22:00 02 Sept 2018, leg. Shuo Liu, same locality as holotype; KIZL201805, adult female, 22:40 02 Sept 2018, leg. Shuo Liu, same locality as holotype; 74I0039 and 74I0040, two gravid females, old specimens in the specimen collection room of Kunming Institute of Zoology, Chinese Academy of Sciences, Aug 1974, leg. Longchuan County, Dehong Autonomous Prefecture, Yunnan, China.

Etymology.

The name refers to Tongbiguan Nature Reserve, the locality where the new species was found.

Diagnosis.

A medium-sized (maximum SVL 115.6 mm) agamid lizard with two pairs of spines: postorbital (supraciliary) spines and spines on occiput between tympanum and nuchal crest; tympanum naked; moderately developed gular pouch; scales on flanks randomly intermixed with medium and large scales; nuchal crest present and strongly developed; diastema between the nuchal and dorsal crests present; dorsal crest slightly developed, composed of enlarged, pointed scales beginning at shoulder region and decreasing regularly in size; tail 1.56-1.85 times SVL; black nuchal collar present; black eye patch present; black oblique folds anterior to the fore limb insertions present.

The new species can be separated from all congeners by having different numbers of subdigital lamellae on the fourth finger (19-21) and toe (25-28), and a different shape of the black eye patch, that extends from posterior margin of nostrils through orbit posteriorly and downwards beyond the posterior end of the tympanum but neither meeting the diamond shaped black nuchal collar on nape nor black oblique humeral fold.

Description of the holotype.

Adult male. SVL 110.8 mm. TL 205.0 mm, tail complete. Head length 31.1 mm; head moderately long (HL/SVL 28%), somewhat narrow (HW/SVL 18%), not tall (HD/HL 52%), triangular in dorsal and lateral profile. Snout short (SL/HL 31%); interorbital and frontal regions and rostrum wide, steeply sloping anteriorly. Canthus rostralis prominent, forming a large projecting ridge extending above eye, composed of 11/13 enlarged scales; the ridge terminates with a notch anterior to the postorbital spine. Rostral moderate in size, rectangular; nasal concave, nostrils surrounded by a circular scale. Eye relatively large (EYE/HL 22%), orbit very large (ORBIT/HL 35%). Prefrontal and frontal scales slightly keeled and larger than scales between supralabials; scales on occiput weakly keeled. Moderately elongate epidermal spine above posterior margin of eye, straight, surrounded by 5/4 enlarged scales. A notch present between the supraciliary edge and postorbital spine. Moderately elongate epidermal spine on occipital region, straight, surrounded by a rosette of 5/4 short spiny scales. Tympanum exposed, oblong, surrounded by small scales. Supralabials 13/13, rectangular, scales in center of series largest; mental squarish above, becoming triangular below, larger than first pair of INFRAL; five scales contacting the mental; infralabials 13/12, rectangular, scales in center of series largest; gulars sharply keeled and spinose. Dewlap extensible, gular pouch moderate. Nuchal crest composed of four very elongate, lanceolate, laterally compressed scales and one moderately elongate, lanceolate, laterally compressed scale bordered on each side by one row of enlarged, spinose scales; nuchal crest followed by a diastema at base of nape. Dorsal body crest slightly developed, 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 smaller paravertebral spinose scales; vertebral crest tapers slightly to base of tail, then fades progressively. Body slightly short, triangular in cross-section. Dorsal scales small, mixed with large scales indistinctly arranged in slanted forward and downward rows from the midline of the back, keels projecting posterior wards; scales of pectoral region and abdomen larger than dorsal scales, keeled, more or less arranged in transverse rows; keeled scales anterior to vent not enlarged. Limbs relatively long (FOREL/SVL 39%, HINDL/SVL 56%); dorsal and ventral scales of forelimbs keeled, spinose, about the same size. Five digits on manus; subdigital scales keeled, subdigital lamellae under fourth finger 20/21. 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 toe 26/27. Tail length 1.85 times SVL, tail covered with keeled spinose scales, keels on subcaudals directed posteriorly; subcaudals much longer than supracaudals; base of tail 13.1 mm wide.

Color of holotype in life.

Dorsal surface of head black, dorsal surface of body and limbs orangish brown; black eye patch extending from posterior margin of nostrils through orbit posteriorly and downwards beyond the posterior end of the tympanum but neither meeting the diamond shaped black nuchal collar on nape nor black oblique folds anterior to the fore limb insertions; upper lip white, same as color of lateral and ventral sides of neck, lower lip white with small black speckle at posterior region; iris orangish brown; black nuchal collar extending downward to reach black oblique folds anterior to fore limb insertions, two white patches at lower back of black nuchal collar; gular region white; postorbital spines, occipital spines, nuchal crest spines and ridge of the rostral and orbit cream-colored; tongue and inside of mouth pink; few small black speckles and yellow diagonal stripes from midline of the back, irregular light colored spots on sides of body not obvious; stripes checkered with black and white on dorsal ground of limbs and tail; ventral sides of limbs and body white, front part white and back part dark on ventral side of tail. However, it should be noted that this species can change the color of its body within a certain range like most other members of the genus.

Variations.

Morphometric and meristic data for the type series are provided in Table 3. The paratypes resemble the holotype in most aspects except that the male KIZL201801 has a darker dorsal ground of the body with no black speckles in the dorsal pattern, and the number of nuchal crest scales is six. The female KIZL201805 has a much darker dorsal ground of the body and irregular black patterns on the ventral sides of the body, limbs, and tail; light colored spots on the sides of the body are more obvious, the color in the gular region is a bit darker. The juveniles KIZL201802 and KIZL201803 have much shorter postorbital, occipital, and nuchal crest spines, and obvious radial patterns around the eyes; the colors of the bodies are relatively darker, the yellow diagonal stripes from the midline of the back are more obvious; they also have irregular black patterns on the ventral sides of the body, limbs, and tail; nuchal crest scales of KIZL201803 numbers four. The females 74II0039 and 74I0040 were not observed alive but only in preservative: the female 74II0039 has a much more obvious black speckling in the dorsal pattern while the female 74II0039 has no black speckles, but they both have irregular black patterns on the ventral sides of the body, limbs, and tail; both have six nuchal crest scales.

Distribution.

Acanthosaura tongbiguanensis  sp. nov. is only recorded in Tongbiguan Nature Reserve including Yingjiang County, Longchuan County and Ruili City, the border region with northern Myanmar in western Yunnan, China, so it probably occurs in northern Myanmar.

Natural history.

The type series of Acanthosaura tongbiguanensis  sp. nov. was collected at night while they were asleep on small trees in a primordial forest. However, we suppose that they forage for food on the ground during the day. At the type locality we found four other species of reptiles, namely Cyrtodactylus khasiensis  (Jerdon, 1870), Pseudocalotes kakhienensis  (Anderson, 1879); P. microlepis  (Boulenger, 1887); Trimeresurus yingjiangensis  Chen et al., 2019; and seven species of amphibians, Leptobrachella yingjiangensis  (Yang et al., 2018); Limnonectes longchuanensis  Suwannapoom et al., 2016; Megophrys feii  Yang et al., 2018; M. glandulosa  Fei et al., 1990; Raorchestes longchuanensis  (Yang & Li, 1978); Theloderma moloch  (Annandale, 1912); Zhangixalus smaragdinus  (Blyth, 1852).

Comparisons.

Table 4 shows a comparison of morphometric and meristic data for all currently recognized species of Acanthosaura  and Acanthosaura tongbiguanensis  sp. nov. It is based mostly on the interspecific comparison tables provided by Pauwels et al. (2015: table 2), Nguyen et al. (2018: table 3) and Nguyen et al. (2019: table 3).

Acanthosaura tongbiguanensis  sp. nov. can be distinguished from A. armata  by having more subdigital lamellae on the fourth finger (19-21 vs. 13-17) and the fourth toe (25-28 vs. 19-26), shorter postorbital spines (3.6-6.3 vs. 4.9-9.9 mm, PS/HL 0.13-0.19 vs. 0.22-0.56) and shorter occipital spines (4.5-7.0 vs. 4.0-9.4 mm, OS/HL 0.16-0.23 vs. 0.16-0.38), much shorter nuchal crest spines (4.0-6.7 vs. 5.5-11.2 mm, NSL/HL 0.15-0.21 vs. 0.22-0.51) and much shorter dorsal crest spines (2.4-4.2 vs. 4.9-11.3 mm, DS/HL 0.09-0.13 vs. 0.20-0.52), a higher number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 1-8), a relatively longer tail (TL/SVL 1.56-1.85 vs. 1.2-1.6). Acanthosaura tongbiguanensis  sp. nov. has a black eye patch (vs. absent) and an obvious black nuchal collar (vs. not obvious or absent); Acanthosaura tongbiguanensis  sp. nov. has fewer or no spots on the dorsal surface of the body, whereas A. armata  has more spots on the dorsal surface of the body.

The new species can be distinguished from Acanthosaura bintangensis  by having a larger tympanum (3.2-4.2 vs. 2.5-3.0 mm, TD/HD 0.21-0.24 vs. 0.16), longer head (27.5-33.2 vs. 16.9-25.4 mm), longer postorbital spines (6.3 vs. 4.2 mm), higher maximal length of spines in the nuchal crest (6.7 vs. 4.7), longer spines in the dorsal crest (2.4-4.2 vs. 1.8-2.2 mm, DS/HL 0.09-0.13 vs. 0.08-0.09), less subdigital lamellae on the fourth finger (19-21 vs. 23), much longer occipital spines (4.5-7.0 vs. 1.2-2.6 mm, OS/HL 0.16-0.23 vs. 0.10-0.11), less scales surrounding the occipital spine (4-5 vs. 6-7), lower number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 11-15), presence of a light knee patch (vs. absence), less developed gular pouch (1-2 vs. 3-4), absence of an enlarged row of keeled scales below orbit (vs. presence), absence of large yellow spots edged in blackish-brown arranged on body and base of tail (vs. presence); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum while it never extends onto the head side in A. bintangensis  ( Wood et al. 2009).

From Acanthosaura brachypoda  , Acanthosaura tongbiguanensis  sp. nov. can be differentiated by having more subdigital lamellae on the fourth finger (19-21 vs. 18) and the fourth toe (25-28 vs. 24), longer postorbital spines (3.6-6.3 vs. 3.2 mm, PS/HL 0.13-0.19 vs. 0.11) and longer occipital spines (4.5-7.0 vs. 1.0 mm, OS/HL 0.16-0.23 vs. 0.03), much longer spines in the dorsal crest (2.4-4.2 vs. 1.9 mm, DS/HL 0.09-0.13 vs. 0.06), the presence of gular pouch (vs. absence). Acanthosaura tongbiguanensis  sp. nov. does not have pairs of transverse creamy spots along both sides of spine forming a symmetrical pattern present as in A. brachypoda  .

Acanthosaura tongbiguanensis  sp. nov. can be distinguished from A. capra  based on its smaller body size (93.0-115.6 vs. 94.0-137.9 mm) but longer tail (144.9-205.0 vs. 133.6-182.1 mm, TL/SVL 1.56-1.85 vs. 1.2-1.5), a higher number of subdigital lamellae on the fourth finger (19-21 vs. 16-17) and the fourth toe (25-28 vs. 22-24), lower maximal length of forelimb (43.2 vs. 83.8 mm) and hindlimb (63.9 vs. 107.2 mm), shorter postorbital spines (3.6-6.3 vs. 5.2-10.2 mm, PS/HL 0.13-0.19 vs. 0.36), nuchal crest spines (4.0-6.7 vs. 4.2-14.7 mm, NSL/HL 0.15-0.21 vs. 0.42-0.43) and dorsal crest spines (2.4-4.2 vs. 3.5-6.8 mm, DS/HL 0.09-0.13 vs. 0.16-0.17),lower width of the nuchal crest spines (1.0-1.5 vs. 2.3-4.1 mm), higher number of scales in the diastema between nuchal and dorsal crests (6-10 vs. 4-7), presence of occipital spines (vs. absence), a smaller gular pouch (1-2 vs. 3-4); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum, while it usually extends backwards and upwards to reach the nuchal crests in A. capra  .

From Acanthosaura cardamomensis  , the new species can be separated based on a higher number of subdigital lamellae on the fourth finger (19-21 vs. 15-20) and the fourth toe (25-28 vs. 20-25), a longer tail (144.9-205.0 vs. 103-188 mm, TL/SVL 1.56-1.85 vs. 1.2-1.6), much shorter postorbital spines (3.6-6.3 vs. 3.2-12.7 mm, PS/HL 0.13-0.19 vs. 0.14-0.45), occipital spines (4.5-7.0 vs. 4.1-13.3 mm, OS/HL 0.16-0.23 vs. 0.24-0.56), nuchal crest spines (4.0-6.7 vs. 3.8-17.4 mm, NSL/HL 0.15-0.21 vs. 0.17-0.66) and dorsal crest spines (2.4-4.2 vs. 2.0-14.2 mm, DS/HL 0.09-0.13 vs. 0.14-0.45), a lower width of nuchal crest spines (1.0-1.5 vs. 1.8-4.2 mm); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum but never reaches the dark nuchal marking on nape while it does so in A. cardamomensis  (see species’ description and photographs in Wood et al. 2010), besides, Acanthosaura tongbiguanensis  sp. nov. has fewer or no spots on the dorsal surface of the body, whereas A. cardamomensis  has more spots on the dorsal surface of the body.

Acanthosaura tongbiguanensis  sp. nov. is distinguishable from A. coronata  based on its much bigger body size (93.0-115.6 vs. 66.0-86.1 mm), much longer tail (144.9-205.0 vs. 86.3-105.0 mm, TL/SVL 1.56-1.85 vs. 0.6-1.0), higher number of subdigital lamellae on the fourth finger (19-21 vs. 17-19) and the fourth toe (25-28 vs. 22-23), relatively larger tympanum (TD/HD 0.21-0.24 vs. 0.14-0.17), bigger rostral (RW 3.4-4.5 vs. 0.8-0.9 mm, RH 1.0-2.0 vs. 0.5-0.8 mm), the presence of postorbital spines, occipital spines, nuchal and dorsal crests (vs. absence or not obvious), a diastema between nuchal crest and dorsal crest (vs. a continuous nuchal and dorsal crest), presence of a black nuchal collar (vs. absence), presence of a black eye patch (vs. absence), and the presence of a gular pouch (vs. absence) (see the original description by Günther 1861 and expanded descriptions by Günther 1864; Boulenger 1885).

Acanthosaura tongbiguanensis  sp. nov. can be differentiated from A. crucigera  by having more subdigital lamellae on the fourth finger (19-21 vs. 16-18) and the fourth toe (25-28 vs. 21-26), a relatively larger tympanum (TD/HD 0.21-0.24 vs. 0.14-0.21), a higher maximal length of tail (205.0 vs. 174.0 mm), a higher maximal length of occipital spines (7.0 vs. 4.9 mm), a lower number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 9-25), a larger mental (MW 1.4-1.9 vs. 1.0-1.5 mm, MH 1.2-2.0 vs. 1.1-1.7 mm). Most obvious is the difference in the color pattern: the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends back and downwards beyond the posterior end of the tympanum, while it only extends to the anterior edge of the tympanum in A. crucigera  ; additionally, Acanthosaura tongbiguanensis  sp. nov. has fewer or no spots on the dorsal surface of the body, whereas A. crucigera  has more spots on the dorsal surface of the body.

Acanthosaura tongbiguanensis  sp. nov. can be separated from A. lepidogaster  based on its higher number of subdigital lamellae on the fourth finger (19-21 vs. 17-19) and the fourth toe (25-28 vs. 22-23), its bigger body size (93.0-115.6 vs. 76.5-101.1 mm), longer postorbital spines (3.6-6.3 vs. 1.5-2.5 mm, PS/HL 0.13-0.19 vs. 0.06-0.11) and longer occipital spines (4.5-7.0 vs. 3.2-3.4 mm, OS/HL 0.16-0.23 vs. 0.14-0.15), longer nuchal crest spines (4.0-6.7 vs. 2.9-3.4 mm, NSL/HL 0.15-0.21 vs. 0.12-0.15) and longer dorsal crest spines (2.4-4.2 vs. 1.5-2.7 mm, DS/HL 0.09-0.13 vs. 0.07-0.12), much higher maximal length of tail (205.0 vs. 144.1 mm), lower number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 10-12), much wider rostral (3.3-4.5 vs. 2.8-3.0 mm), and larger gular pouch (1-2 vs. 0-1). The black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backwards and downwards beyond the posterior end of the tympanum but never backwards and upwards to reach the black nuchal collar, while it usually does so in A. lepidogaster  ; the black nuchal collar extends downwards to reach the black oblique humeral fold, while it rarely reaches the black oblique humeral fold in A. lepidogaster  ; besides, the tongue and the inside of the mouth are pink in Acanthosaura tongbiguanensis  sp. nov., while they are bluish-grey or black in A. lepidogaster  ; the postorbital spines, occipital spines, nuchal crest spines, the ridge of the rostralis, and orbit are lighter in color in Acanthosaura tongbiguanensis  sp. nov., whereas they are darker in color in A. lepidogaster  .

Acanthosaura tongbiguanensis  sp. nov. can be separated from A. murphyi  based on its smaller body size (93.0-115.6 vs. 103.7-127.3 mm) but relatively longer tail (TL/SVL 1.56-1.85 vs. 1.48-1.54), a higher number of subdigital lamellae on the fourth finger (19-21 vs. 15-18) and the fourth toe (25-28 vs. 21-23), shorter forelimb (34.7-43.2 vs. 49.8-56.6 mm) and hindlimb (54.1-63.9 vs. 60.4-68.4 mm), much shorter postorbital spines (3.6-6.3 vs. 5.6-11.8 mm, PS/HL 0.13-0.19 vs. 0.16-0.34), nuchal crest spines (4.0-6.7 vs. 7.0-14.9 mm, NSL/HL 0.15-0.21 vs. 0.24-0.43) and dorsal crest spines (2.4-4.2 vs. 2.6-10.5 mm, DS/HL 0.09-0.13 vs. 0.14-0.51), much lower width of the nuchal crest spines (1.0-1.5 vs. 2.9-4.8 mm), higher number of scales in the diastema between nuchal and dorsal crests (6-10 vs. 4-8), presence of occipital spines (vs. absence), a smaller gular pouch (1-2 vs. 4); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum, while it usually extends backwards and upwards to reach the nuchal crests in A. murphyi  (see species’ photographs in Nguyen et al. 2018).

Acanthosaura tongbiguanensis  sp. nov. can be separated from A. nataliae  by its smaller body size (93.0-115.6 vs. 106.7-158.0 mm) and a lower maximal tail length (205.0 vs. 287.0 mm) but a relatively longer tail (TL/SVL 1.56-1.85 vs. 1.2-1.5), much shorter length of postorbital spines (3.6-6.3 vs. 7.7-17.8 mm, PS/HL 0.13-0.19 vs. 0.36), nuchal crest spines (4.0-6.7 vs. 8.5-23.8 mm, NSL/HL 0.15-0.21 vs. 0.58) and dorsal crest spines (2.4-4.2 vs. 6.0-17.7 mm, DS/HL 0.09-0.13 vs. 0.44), a lower width of the nuchal crest spines (1.0-1.5 vs. 3.1-4.8 mm), lower width of mental (1.4-1.9 vs. 2.9 mm), a lower number of ventral scales (52-66 vs. 64-71), lower maximal length of forelimb (43.2 vs. 85.0 mm) and hindlimb (63.9 vs. 129.7 mm), presence of occipital spines (vs. absence), much lesser development of gular pouch (1-2 vs. 4), presence of light knee patch (vs. absence) and presence of a black nuchal collar (vs. absence); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum but never continues backward to reach the black oblique folds anterior to the fore limb insertions while it usually does so in A. nataliae  (see species’ description and photographs in Orlov et al. 2006).

Acanthosaura tongbiguanensis  sp. nov. is distinguishable from A. phongdienensis  based on its bigger body size (93.0-115.6 vs. 58.5-77.4 mm), longer tail (144.9-205.0 vs. 94.6-137.2 mm), higher number of subdigital lamellae on the fourth finger (19-21 vs. 14-17) and the fourth toe (25-28 vs. 19-23), longer postorbital spines (3.6-6.3 vs. 1.18-2.07 mm, PS/HL 0.13-0.19 vs. 0.06-0.09), longer nuchal crest spines (4.0-6.7 vs. 1.24-4.18 mm, NSL/HL 0.15-0.21 vs. 0.07-0.18) and longer dorsal crest spines (2.4-4.2 vs. 0.58-1.65 mm, DS/HL 0.09-0.13 vs. 0.03-0.07), a diastema between nuchal crests and dorsal crests (vs. a continuous nuchal and dorsal crest); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backwards and downwards beyond the posterior end of the tympanum but never backwards and upwards to reach the black nuchal collar, while it does so in male A. phongdienensis  (see species’ description and photographs in Nguyen et al. 2019), the postorbital spines, occipital spines, nuchal crest spines, the ridge of the rostralis and orbit are lighter in color in Acanthosaura tongbiguanensis  sp. nov., whereas they are darker in color in A. phongdienensis  .

Acanthosaura tongbiguanensis  sp. nov. can be differentiated from A. phuketensis  by having a higher number of subdigital lamellae on the fourth finger (19-21 vs. 15-17) and the fourth toe (25-28 vs. 21-24), a relatively longer tail (TL/SVL 1.56-1.85 vs. 1.4-1.7), much shorter postorbital spines (3.6-6.3 vs. 4.6-11.8 mm, PS/HL 0.13-0.19 vs. 0.23-0.38), nuchal crest spines (4.0-6.7 vs. 4.1-12.2 mm, NSL/HL 0.15-0.21 vs. 0.21-0.39) and dorsal crest spines (2.4-4.2 vs. 2.3-8.3 mm, DS/HL 0.09-0.13 vs. 0.11-0.26), a lower width of nuchal crest spines (1.0-1.5 vs. 1.4-2.9 mm), a lower maximal length of occipital spines (7.0 vs. 9.5 mm), a lower number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 12-17), a bigger mental (MW 1.4-1.9 vs. 0.5-1.4 mm, MH 1.2-2.0 vs. 0.6-1.6 mm); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. never extends backward to reach the nuchal crest while it does so in male A. phuketensis  (see species’ original description by Pauwels et al. 2015) and Acanthosaura tongbiguanensis  sp. nov. has fewer or no spots on the dorsal surface of the body, whereas A. phuketensis  has more spots on the dorsal surface of the body.

From Acanthosaura titiwangsaensis  , the new species can be distinguished by its relatively larger tympanum (TD/HD 0.21-0.24 vs. 0.17-0.20), its longer tail (144.9-205.0 vs. 136.0-174.0mm, TL/SVL 1.56-1.85 vs. 1.1-1.5), higher maximal length of postorbital spines (6.3 vs. 4.4 mm) and nuchal crest spines (6.7 vs. 4.4 mm), higher length of dorsal crest spines (2.4-4.2 vs. 1.7-2.1 mm, DS/HL 0.09-0.13 vs. 0.07-0.09), much longer occipital spines (4.5-7.0 vs. 1.8-2.3 mm, OS/HL 0.16-0.23 vs. 0.09-0.10), lower number of scales in the diastema between the nuchal and the dorsal crests (6-10 vs. 10-13), presence of a light knee patch (vs. absence), less developed gular pouch (1-2 vs. 2-4), absence of medium-sized light orange spots edged in a faded black color on body and base of tail (vs. presence); the black eye patch in Acanthosaura tongbiguanensis  sp. nov. extends backward and downward beyond the posterior end of the tympanum while it is restricted to the orbit and not extends into the postorbital region in A. titiwangsaensis  ( Wood et al. 2009).

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Squamata

Family

Agamidae

Genus

Acanthosaura