Acanthosaura phongdienensis, Nguyen & Jin & Vo & Nguyen & Zhou & Che & Murphy & Zhang, 2019

Nguyen, Sang Ngoc, Jin, Jie-Qiong, Vo, Ba Dinh, Nguyen, Luan Thanh, Zhou, Wei-Wei, Che, Jing, Murphy, Robert W. & Zhang, Ya-Ping, 2019, A new species of Acanthosaura Gray 1831 (Reptilia: Agamidae) from central Vietnam, Zootaxa 4612 (4), pp. 555-565 : 559-561

Acanthosaura phongdienensis sp. nov.

Holotype ( Fig. 2 ). KIZ 10695, an adult male collected on 22 October 2010, 16 o 28’ 03.6” N, 107 o 16’ 40.8” E, at Phong Dien Nature Reserve , Thua Thien-Hue Province, Vietnam (site 8, Fig. 1), about 197 m a.s.l. by Robert W. Murphy, Wei-Wei Zhou, Ba Dinh Vo, Luan Thanh Nguyen, and Sang Ngoc Nguyen.

Paratypes. ROM 48013 and ITBCZ 6830, adult males; KIZ 10657, KIZ 10697, and ITBCZ 6831, adult females; and KIZ 10617, a sub-adult male ( Table 3 ). Other data were the same as for the holotype except for KIZ 10464, which was collected in September 2010 at an elevation of 1019 m a.s.l.

Diagnosis. Medium size, SVL 73–77 mm in males and 59–65 mm in females; TL much longer than SVL; rostral scute entire; nuchal spine at middle of nuchal crest and tympanum; tympanum naked; postorbital spine about one half of ED; nuchal and dorsal crests continuous ( Figs. 2–4 ); lateral scales small, intermixed with large, keeled scales whose keels point backward and back-upward; SL 9–12; IL 10–11.

Description of holotype. Adult male, SVL 74.2 mm. SL 11, IL 10. Head moderately tall (HH/HL = 0.63) and with HH/HW = 0.94. Rostral entire and wide, nearly trapezoidal (RH/RW = 0.5), upper wider than lower, not touching nostril, bordered posteriorly by four smaller smooth scale and laterally by first supralabials. When mouth closed, rostral in contact with mental and first infralabials. Nasals with pits, not touching supralabials. Scales on dorsum of head large and keeled. Canthus-rostralis-supraciliary scales slightly serrated, composed of 11 enlarged scales, separated from postorbital spine by a notch. Postorbital spine length about one half ED. An enlarged scale row below orbit. Interorbital scales keeled. Nuchal spine present midway between nuchal crest and tympanum, surrounded by spine-like scales. Tympanum naked, not round, surrounded by small scales. TD smaller than ED. A row of large and keeled scales from posterior edge of orbit to nuchal spine. Mental nearly pentagonal, posteriorly in contact with two elongate postmentals that contact with each other. Throat with two large scale rows parallel with infralabials. Gular scales strongly keeled except for smooth scales near the mental. Standard counts and measurements provided in Table 3 .

Body elongate with dorsal and nuchal crest connected by lower crests ( Fig. 2B ). Nuchal crests longer than dorsal ones (3.81 mm vs. 1.56 mm) that reduce posteriorly. Dorsal scales heterogeneous, small, imbricate, intermixed with large, strongly keeled scales that have points directed backward or back-upward. An oblique fold in each side of neck, in front of shoulder. Ventrals strongly keeled. Limbs slender. Hind limb stretched forwards reaches nostril. Dorsal surface of limbs with large, strongly keeled scales. Narrow subdigital lamellae under fourth finger and toe 14 and 20, respectively. Tail longer than snout–vent length (TL/SVL = 1.8), covered with uniform strongly keeled scales; postcloacal region of tail strongly swollen.

In life, dorsum of body green with black lateral blotches. Venter whitish. Large black area in front of shoulder. Green to yellow-green wide band expands from snout through labials, tympanum, and neck to lateral of body. Upper side of head and neck black. Upper part of lateral view of head and neck also black. Black colored area becomes narrow at neck and expands at dorsum forming a diamond-shaped band in dorsal view. Tips of nuchal and postorbital spines, and nuchal crests yellow-green. Iris brown with a round pupil. Elbow and knee with white blotches. Original tail dark brown with white-cream or light green alternating rings.

In preservative ( Fig. 2 ), color faded with unchanged pattern. Upper side of body and limbs with alternating turquoise, white, and black blotches. Labials, tympanum, and lateral view of neck white.

DNA Barcode. Type series with GenBank Accession No. MK 695205 – MK 695210 .

Variation. Males significantly larger than females (SVL 74.9 mm versus 61.4 mm; p <0.01). Relative tail length of males significantly longer than females (TL/SVL 1.8 versus 1.6, p <0.01). Rostral scale in paratype KIZ 10657 half-separated from upper but still forms an entire scale. Spines and crests of females shorter than those of males. Variation in size and squamation provided in Table 3 . Color and pattern of males and females differ; males similar to holotype with green ground color, green to yellow at labial, tympanum to lateral of neck, upper side of head and neck black or dark brown. Females with brown color on dorsal and lateral views ( Fig. 4 ). Lateral side of head in female radiatiform from eye through labials. Juvenile color pattern unknown.

Figures

FIGURE 2. Holotype of Acanthosaura phongdienensis sp. nov. A, dorsal-lateral view; B, Close-up to the connection between nuchal and dorsal crests; C, lateral view of head.

FIGURE 3. Acanthosaura phongdienensis sp. nov. (left) and A. cf. lepidogaster from northern Vietnam (Phu Tho Prov.) (right). Red arrows show the continuity of nuchal and dorsal crests in the new species, while crests in the later species are clearly separated by a long diastema covered by small scales.

FIGURE 4. Acanthosaura phongdienensis sp. nov. in life. Female (upper) is brown and male (lower) exhibits green-dark colors.

Tables

TABLE 3. Measurements (in mm) and scale counts for the type series of Acanthosaura phongdienensis sp. nov. SVL and TL in males and females were calculated rately. The sub-adult male was excluded in range and mean SD calculations. For character abbreviations see Materials and Methods.

	Holotype	Paratypes						Range	mean ± SD
	KIZ 10695	ROM 48013	ITBCZ 6830	KIZ 10697	ITBCZ 6831	KIZ 10657	KIZ 10617
Sex	Male	Male	Male	Female	Female	Female	Sub-male
SVL	74.2	77.4	73.2	58.5	64.7	60.9	62.2	m: 73.2–77.4 f: 58.5–64.7	74.9 ± 2.2 61.4 ± 3.1
TL	132.6	136.2	137.2	97.5	94.6	99.5	104.7	m: 132.6–137.2 f: 94.6–99.5	135.3 ± 2.4 97.2 ± 2.5
TL/SVL	1.8	1.8	1.9	1.7	1.5	1.6	1.7	1.8–1.9 1.5–1.7	1.8 ± 0.1 1.6 ± 0.1
HL	22.4	23.8	21.9	18.6	19.6	18.7	17.8	18.6–23.8	20.8 ± 2.2
HW	14.4	15.9	15.3	13.3	13.8	13.1	12.6	13.1–15.9	14.3 ± 1.1
HH	13.5	13.6	13.1	10.7	11	10.4	10.5	10.4–13.6	12.1 ± 1.5
MW	1.35	1.52	1.33	0.87	1.03	1.44	1.3	0.87–1.52	1.3 ± 0.3
MH	1.36	1.60	1.60	1.07	1.04	1.52	1.4	1.04–1.60	1.4 ± 0.3
RW	2.65	2.47	2.46	2.33	2.10	2.07	2.13	2.07–2.65	2.3 ± 0.2
RH	1.32	1.16	1.14	1.08	1.00	1.17	1.23	1.00–1.32	1.1 ± 0.1
ED	3.97	4.17	4.00	3.10	3.42	3.18	3.3	3.10–4.17	3.6 ± 0.5
TD	2.81	2.68	2.38	1.92	2.41	1.78	1.62	1.78–2.81	2.3 ± 0.4
PS	2.07	–	–	1.18	1.28	1.54	–	1.18–2.07	1.5 ± 0.4
NS	2.64	4.15	2.26	1.53	2.19	2.34	2.45	1.53–4.15	2.5 ± 0.9
NC	3.81	4.18	3.77	1.84	2.28	1.24	1.75	1.24–4.18	2.9 ± 1.2
DC	1.56	1.65	1.31	0.65	0.61	0.58	1.55	0.58–1.65	1.1 ± 0.5
SL	11	11	10	11	12	9	10	9–12	10.6 ± 1.0
IL	10	11	11	11	11	10	11	10–11	10.7 ± 0.5
CS	11	13	12	11	9	11	12	9–13	11.3 ± 1.3
F4	14	15	17	15	15	15	15	14–17	15.1 ± 0.9
T4	20	20	23	19	21	20	22	19–23	20.7 ± 1.4

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