Takydromus yunkaiensis J. Wang, Lyu & Y.Y. Wang

Wang, Jian, Lyu, Zhi-Tong, Yang, Chen-Yu, Li, Yu-Long & Wang, Ying-Yong, 2019, A new species of the genus Takydromus (Squamata, Lacertidae) from southwestern Guangdong, China, ZooKeys 871, pp. 119-139 : 125-131

Takydromus yunkaiensis J. Wang, Lyu & Y.Y. Wang sp. nov. Fig. 3

Material.

Holotype. SYS r001580 , adult male, collected by Jian Wang on 16 August 2016 from Dawuling Forestry Station (22°16'32.90"N, 111°11'42.87"E; 1500 m a.s.l.), Yunkaishan National Nature Reserve , Xinyi City , Guangdong Province , China.

Paratypes. Three adult males, collected by Ying-Yong Wang, Jian Wang, Zhi-Tong Lyu and Zhao-Chi Zeng: SYS r001439 , 1442 on 15 and 16 April 2016, SYS r001684 on 17 April 2017, all from Dawuling Forestry Station (1200-1500 m a.s.l.). Six adult females: SYS r001513 and SYS r001514 collected by Jian Wang on 9 July 2016 from Xianrendong Scenic Area (22°165'45.99"N, 111°13'16.35"E; 1000 m a.s.l.), Yunkaishan National Nature Reserve , Xinyi City , Guangdong Province ; SYS r001434 collected by Jian Wang and Zhi-Tong Lyu on 14 April 2016, SYS r001507 collected by Jian Wang on 28 June 2016, SYS r001581 collected by Jian Wang on 16 August 2016, and SYS r001901 collected by Jian Wang and Hong-Hui Chen on 10 April 2018, all from Dawuling Forestry Station (1200-1500 m a.s.l.).

Etymology.

The specific epithet, yunkaiensis , is in reference to the type locality of the new species. We propose the standard name "Yunkai grass lizard" and the Chinese name "Yun Kai Cao Xi ( 云开草蜥)”.

Diagnosis.

(1) body size moderate, SVL 37.8-56.0 mm in males, 42.6-60.8 mm in females; (2) dorsal ground color brown; ventral surface green to yellow-green, but light blue-green on ventral head and neck, posteriorly green in adult males; (3) dorsolateral lines paired, strikingly yellowish-white bordered by black above and below, invisible or indistinct i n juveniles and adult females; (4) flanks of body blackish brown with light brown marks in adult males; (5) the presence of four pairs of chin-shields; (6) four supraoculars on each side; (7) presence of a row of supracilary granules that separate supracilaries from supraoculars; (8) two postnasals; (9) enlarged dorsal scales with strong keel in six longitudinal rows on trunk of body; (10) enlarged ventral scales in six longitudinal rows, strongly keeled in males, smooth but outermost rows weakly keeled in fe males; (11) enlarged and keeled lateral scales in a row above ventrals; (12) femoral pores 2-3 on each side; (13) subdigital lamellae 20-23 under the fourth finger, 23-30 under the fourth toe; and (14) the first 2-3 subdigital lamellae under the fourth toe divided.

Comparisons.

In this study we only compare the new species with the other 22 recognized species, excluding Takydromus haughtonianus , which is currently an uncertain species and poorly known (Jerdan 1870; Arnold 1997). Measurements, body proportions, and scale counts of the new species are listed in Tables 3 and 4; comparative data of the new species and nine other recognized members of the genus Takydromus occurring on the Chinese mainland are listed in Tables 5 and 6.

In our phylogenetic tree, Takydromus yunkaiensis sp. nov. is a sister taxon to T. intermedius , from which it differs by having two postnasals (only one in T. intermedius ), having a pair of strikingly yellowish-white dorsolateral lines in adult males (vs. always absent or indistinct in T. intermedius ), flanks of body blackish brown with light brown spots in adult males (vs. pure brown without spots in T. intermedius ), ADSR 9-10, PDSR 7 (vs. ADSR 6-8, PDSR 6 in T. intermedius ).

Morphologically, Takydromus yunkaiensis sp. nov. is most similar to T. kuehnei ( Fig. 4 ). The new species can be distinguished from T. kuehnei by having a pair of strikingly yellowish-white dorsolateral lines in adult males (vs. absent or dorsolateral stripes blurred, pale brown only present in old individuals in T. kuehnei ); surface of ventrals green (vs. surface of ventrals white or light yellow in T. kuehnei ), ADSR 9-10, PDSR 7 (vs. ADSR 5-7, PDSR 6 in T. kuehnei ); TaL/SVL 2.59-2.77 in males (vs. tail relatively longer, TaL/SVL 3.07-3.08 in T. kuehnei ); relatively shorter trunk (arm-leg length), ALL/SVL 0.46-0.51 in males, 0.48-0.51 in females (vs. relatively larger arm-leg length, ALL/SVL 0.52-0.53 in males and 0.58 in female of T. kuehnei ).

From the remaining six Takydromus species which occur on mainland China ( T. albomaculosus , T. amurensis , T. wolteri , T. septentrionalis , T. sexlineatus , and T. sylvaticus ), Takydromus yunkaiensis sp. nov. can be distinguished by having dense mottles on flanks in males (vs. several particular white round spots on the flanks in T. albomaculosus ; white ocellus bordered by black edges in males of T. sexlineatus ); dorsum brown (vs. dorsum green in T. sylvaticus ); four pairs of chin-shields (vs. three in T. septentrionalis and T. sexlineatus ); two or three pairs of femoral pores (vs. only one in T. wolteri , T. septentrionalis and T. sexlineatus ; four in T. amurensis ); IFL 6-7 (vs. 4-5 in T. sexlineatus ); SPO 4 (vs. three in T. sexlineatus ); ADSR 9-10 (vs. six in T. albomaculosus and T. sexlineatus ; 7-8 in T. amurensis ; 6-8 in T. septentrionalis ); PDSR 7 (vs. six in T. albomaculosus ; 4-6 in T. septentrionalis ; four in T. sexlineatus ; 9-10 in T. sylvaticus ); MDSR 7-8 (vs. 5-6 in T. septentrionalis ; 4 in T. sexlineatus ; 11-14 in T. sylvaticus ); LDSN 47-51 (vs. 56 in T. wolteri ; 67-81 in T. sylvaticus ); ESRF 1 (vs. three in T. wolteri ; 2-3 in T. septentrionalis and T. sexlineatus ; none in T. sylvaticus ).

Takydromus yunkaiensis sp. nov. differs from T. formosanus , T. hsuehshanensis , T. luyeanus , T. sauteri , T. stejnegeri , and T. viridipunctatus , which only occurred in Taiwan Island of China, by having four pairs of chin-shields (vs. three pairs in T. formosanus , T. viridipunctatus , T. luyeanus , T. hsuehshanensis and T. stejnegeri ); FP 2-3 pairs (vs. only one in T. sauteri and T. stejnegeri ); VR 6 (vs. eight in T. formosanus , T. stejnegeri , T. viridipunctatus and T. luyeanus ); ventrals keeled (vs. ventrals smooth in T. hsuehshanensis ); mottles on flanks in males (vs. absent in males of T. formosanus , T. sauteri and T. stejnegeri ); surface of ventrals green (vs. surface of ventrals white in T. formosanus , T. hsuehshanensis , and T. sauteri ); rostral and nostril separated (vs. rostral touching nostril in T. sauteri ); dorsum brown (vs. dorsum green in T. sauteri ).

Takydromus yunkaiensis sp. nov. differs from T. dorsalis , T. smaragdinus , T. tachydromoides , and T. toyamai , which only occur in Japan, by having a brown dorsum (vs. green dorsum in T. dorsalis , T. smaragdinus , and T. toyamai ); dorsal scales large, in longitudinal rows (vs. dorsal scales small, not in obvious longitudinal rows in T. dorsalis ); FP 2-3 pairs (vs. only one in T. smaragdinus and T. toyamai ); ventrals keeled (vs. smooth in T. tachydromoides ); VR 6 (vs. 8 in T. tachydromoides and T. toyamai ); CS 4 pairs (vs. 3 in T. smaragdinus and T. toyamai ).

Takydromus yunkaiensis sp. nov. differs from the remaining four members, T. hani and T. madaensis from Vietnam, T. khasiensis and T. sikkimensis from India, by having the dorsum brown (vs. dorsum green in T. hani ); VR 6 (vs. 8 in T. hani and T. khasiensis ; VR 12 in T. sikkimensis ); CS 4 pairs (vs. 3 in T. khasiensis and T. sikkimensis ); FP 2-3 pairs (vs. FP 6-8 in T. hani ); loreals 2 (vs. 3 in T. madaensis ); SPO 4 (vs. 3 in T. madaensis ); SDLT-4 23-30 (vs. SDLT-4 17 in T. madaensis ).

Description of holotype.

Adult male. Body size slightly small, SVL 43.0 mm; trunk of body short, ALL 19.7 mm, 46 % of SVL; head slightly long, HL 11.1, HW 6.7 mm, HH 5.2 mm, HL 26 % of SVL; skull length larger than head length, SKL 11.9 mm; snout moderately long, SEL in 5.0 mm, SEL 45 % of HL. Rostral large, pentagonal, visible in dorsal view, in contact with the first supralabials posteriorly on both sides, and supranasals dorsolaterally; nostril surrounded by a supranasal, two postnasals and the first supralabial on each side; one supranasal on each side, large, in contact with each other dorso-medially, separating rostral from frontonasal, and in contact with the upper postnasal posteriorly, not in contact with the anterior loreal; postnasals two, both in contact with the anterior loreal posteriorly, the upper one in contact with supranasal dorsolaterally, with frontonasal dorsally, the lower one in contact with the first supralabial ventrally; supralabials six on each side, the fifth one largest, under the eye; two loreals on each side, anterior one smaller than posterior one; posterior loreal in contact with anteriormost supraocular and anteriormost supraciliary scale posteriorly; four supraoculars on each side, the posteriormost one much smaller than others; supraciliaries four on left side, the second one longest; supraciliaries two on right side, the first one longest; supracilary granules arranged in a row, separated supracilaries from supraoculars; frontonasal large, smooth, hexagonal, separated from frontal by a pair of prefrontals; prefrontals two, weakly keeled, in contact with each other medially, with frontal and anterior two supraoculars posteriorly, with loreals laterally, respectively; a single frontal hexagonal, weakly keeled, in contact with second and third supraoculars laterally, with frontoparietals posteriorly; frontoparietals two, pentagonal, in contact with each other medially, with parietal and interparietal posteriorly, respectively; interparietal diamond, surrounded by two frontoparietals, two parietals and the single occipital; parietal pit located in the central of interparietal, distinctly visible; parietals two, large, weakly keeled, slightly in contact with each other medially; a single occipital between two parietals; temporal scales granular, slightly keeled; supratemporals three on each side, keeled, anteriormost one largest, longer than total length of posterior two; mental large, semielliptical; infralabials six on each side; four pairs of chin-shields, anterior two pairs in contact with each other medially, posterior two pairs separated from each other by gular scales; following gular scales gradually increasing in size, keeled, and become imbricated; enlarged, strongly keeled median gular scales extending anteriorly to the line joined posterior edges of ears; collars clear, composed of scales in ten rows pointed backwards, and forming a free serration; enlarged, imbricated dorsal scales on body with strong keel oriented posteriorly that form continuous ridges, extending anteriorly beyond forelimbs on to the nape, in nine rows in position of forelimbs, seven rows in position of hindlimbs; seven rows at mid-body, including a much smaller and discontinuous central row; longitudinal dorsal scales (LDSN) 47; ventrals in six rows, imbricate, strongly keeled and pointed posteriorly; enlarged and keeled lateral scales in a row above ventrals; longitudinal ventral scales (VN) 24; small flat and granular scales in a transverse row on flank at mid-body (SSRF) 14 on left side and 15 on right side, including a row of scales (enlarged and keeled, shorter than ventrals) adjoining the ventrals; four rows of scales on lower flanks reduced, flattened, keeled; nine rows of small granular scales on upper flanks on left side and ten on right side; a discontinuous row of scales adjoining outermost dorsal scale row reduced, flattened, keeled; a total of 42 scales (MBSR) in a transverse row in mid-body region; a single precloacal entire, enlarged, surrounded by eight continuous moderately sized scales anteriorly and laterally; three femoral pores on each side.

Forelimbs moderately long, RUL 5.6 mm, 13% of SVL; scales on anterior and dorsal surfaces of upper arm enlarged, keeled, rhomboid, imbricate, in seven rows; scales on ventral surface of upper arm granular, homogeneous in size; scales on upper insertion of upper arm granular; scales on dorsal surface of forearm keeled, heterogeneous in size, extending to wrist; dorsal scales on hand slightly keeled; scales on palm granular; dorsal scales on fingers in a row, smooth; subdigital lamellae under fingers I–V respectively (left/right) 9/9 (3 entire + 1 divided + 1 entire), 12/12 (6 entire + 5 divided + 1 entire), 16/16 (10 entire + 5 divided + 1 entire), 22/22 (15 entire + 6 divided + 1 entire), 13/13 (6 entire + 6 decided + 1 entire); relative lengths of adpressed fingers I <V <II <III <IV; hindlimbs slender and long, fourth toe reaching the posterior edge of insertion of upper arm when hindlimb adpressed along the side of the body; HLL 25.4 mm, 59% of SVL, 129% of ALL; TFL 6.3 mm, 15% of SVL; LTL 7.9 mm, 18% of SVL; three rows of large smooth scales running beneath thigh with traces of a fourth row; two rows of enlarged keeled scales and one rows of small keeled scales on dorsal surface of thigh; granular scales homogeneous in size on rear of thigh; internal tibial scale of row one formed by enlarged and smooth tibial scale; dorsal tibial scale flat, keeled, heterogeneous in size, extending to dorsal surface of foot; scales on sole of the foot granular; dorsal scales on toes in a row, smooth; subdigital lamellae under toes I–V respectively (left/right) 9/9 (2 entire + 6 divided + 1 entire), 13/14 (7 entire + 5/6 divided + 1 entire), 18/21 (11 entire + 6 divided + 1 entire), 26/26 (2 divided + 17 entire + 6 divided + 1 entire), 18/18 (2 divided + 7 entire + 7 divided + 1 entire); basal two subdigital lamellae of toe IV and V divided; relative lengths of adpressed toes I <II <V <III <IV.

Tail original, TaL 111.3 mm, TaL/SVL ratio 259%, SVL/TaL ratio 39 %, with strongly keeled scales in 15 rows at base (fifth subcaudal scale), in 13 rows in position of the 13th to 15th subcaudal scales (CSR); paired vertebral series of large scales on tail extending on to hind body.

Coloration of holotype in life.

Dorsal surface of head, body, limbs, and tail bright brown, with a pair of strikingly yellowish-white dorsolateral lines bordered by black above and below, each beginning from the posterior margin of the most last supratemporal, running along outermost dorsal scale row, posteriorly extending to the forepart of the tail; flanks of body blackish brown with light brown marks; a pair of orange ventrolateral lines beginning from axilla, running along lower part of flanks, posteriorly extending to the groin; labial series, mental, chin-shields, granular scales on throat, collars light blue-green, posteriorly yellowish green from chest, venter, until to subcaudal region; ventral surface of limbs brown, tinged with green.

Coloration of holotype in preservative.

Dorsal surface of head, body, limbs and tail brown; labial series, mental, chin-shields, granular scales on throat, ventral surface of body and tail pale blue; mottles on flanks blurry, color of mottles on flanks faded; ventral surface of limbs beige; dorsolateral stripes greyish white with black-brown edges at the inner sides; color of ventrolateral stripes faded, greyish white.

Variations and sexual dimorphism.

Measurements, body proportions, and scale counts of the type series of Takydromus yunkaiensis sp. nov. are listed in Tables 2 and 4.

In the holotype SYS r001580, there are four supraciliaries on left side and two on right side, the first one longest on right side, the second supraciliary longest on left side (vs. four supraciliaries on each side, and the second one longest in the paratypes SYS r001439, 1440, 1442, 1513, 1514, 1581, 1684, 1901; three supraciliaries on each sides, and the second one longest in the paratype SYS r001507); prefrontal in contact with the anterior two supraoculars posteriorly in the holotype (vs. prefrontal only in contact with the first supraocular posteriorly on the right side of the paratype SYS r001439); three pairs of femoral pores in the holotype (vs. only two pairs present in the paratypes SYS r001513, 1514); tail relatively longer in two of the female paratypes, TaL/SVL 2.97 in SYS r001581 and 3.02 in SYS r001901 (vs. TaL/SVL 2.59 in the holotype).

Takydromus yunkaiensis sp. nov. exhibits noticeable sexual dimorphism:

(1) enlarged ventral scales strongly keeled in males (vs. smooth but outermost rows weakly keeled in females);

(2) dorsolateral lines strikingly yellowish-white bordered by black above and below (vs. invisible or indistinct in adult females, also in juveniles);

(3) a pair of orange ventrolateral lines present on lower flanks (vs. invisible in females, also in juveniles);

(4) flanks of body blackish brown with light brown marks in adult males (vs. absent in females).

Distribution and habits.

Currently, Takydromus yunkaiensis sp. nov. is known only from its type locality of Dawuling Forestry Station, adjacent Xianrendong Scenic Area located in the southern Yunkai Mountains in western Guangdong Province, China ( Fig. 1 ).

The diurnal species was found to be very active in daytime and rapidly escapes when disturbed, and is usually observed resting on fern leaves at night. The surrounding environment was covered by well-preserved montane evergreen broad-leaved forest or mixed forest ( Fig. 5 ) at altitudes of 900-1600 m.

Figures

Figure 1. The type locality of Takydromus yunkaiensis sp. nov., Yunkaishan Nature Reserve.

Figure 3. Morphological features of the adult male holotype SYS r 001580 of Takydromus yunkaiensis sp. nov. in life. A Habitus view and close-up of flank B close-up of dorsal body C close-up of ventral body D-G close-up of head scales.

Figure 4. Sexual dimorphism in color patterns. A Male paratype of Takydromus yunkaiensis sp. nov. (SYS r 001439) B female paratype of T. yunkaiensis sp. nov. (SYS r 001901) C male topotype of T. intermedius (SYS r 001601) from Mt. Emei, China D female topotype of T. intermedius (SYS r 001602) from Mt. Emei, China E male T. kuehnei (SYS r 001268) from Jiulianshan Nature Reserve, China F female topotype of T. kuehnei (SYS r 001798) from Taiwan Island, China.

Figure 5. Habitat of Takydromus yunkaiensis sp. nov. in Yunkaishan Nature Reserve.