A new skink of the genus Scincella Mittleman, 1950 (Squamata: Scincidae) from Ba Den Mountain, Tay Ninh Province, southern Vietnam Nguyen, Sang Ngoc Nguyen, Vu Dang Hoang Nguyen, Luan Thanh Murphy, Robert W. Zootaxa 2019 2019-07-30 4648 2 273 286 8GQB2 Nguyen & Nguyen & Nguyen & Murphy, 2019 Nguyen & Nguyen & Nguyen & Murphy 2019 [151,403,854,881] Reptilia Scincidae Scincella Animalia Squamata 5 278 Chordata species badenensis sp. nov.  ( Figs. 3–5)     Holotype. ITBCZ 5966, adult male, collected from Ba Den Mountain, Tay Ninh Province, Vietnam; coordinates 11°22’01.6” N, 106°10’26.4” E; elevation 74 ma.s.l.by Sang N. Nguyenand Vu D.H. Nguyen, on  25 June 2017( Figs. 3& 4).    Paratypes. Six specimens, also collected from Ba Den Mountainby Sang N. Nguyenand VuD.H. Nguyen: ITBCZ 5878, adult male ( Figs. 5A&B) and ITBCZ 5879, gravid female ( Fig.  5I), collected on  24 March 2017, coordinates 11°22’14.5” N, 106°10’45.3” E, elevation 130 ma.s.l.;  ITBCZ 5965( Figs. 5C&D) and ITBCZ 5967( Figs. 5E&F), adult males, same data as the holotype;  ITBCZ 5993, gravid female ( Fig. 5J), collected on  25 June 2017, coordinates 11°22’11.1” N, 106°09’58.9” E, elevation 254 ma.s.l.; and ITBCZ 6262, adult male(  Figs. 5G&H), collected on  22 January 2018, coordinates 11°22’41.9” N, 106°10’69.3” E, elevation 810 ma.s.l.  Diagnosis.  Scincella badenensis  sp. nov.is distinguished from all of its congeners by a combination of the following morphological characters: medium size in adults ( SVLup to 64.4 mm); toes reach to fingers when limbs adpressed; 32–36 smooth midbody scale rows; dorsal scales not enlarged; 67–71 paravertebral scales; 68–74 ventral scale rows; four supraoculars; prefrontals in broad contact with one another; two loreal scales; seven, rarely eight, supralabials, the fifth, rarely sixth, below the center of the eye; two anterior and two or three posterior enlarged temporal scales; tympanum deeply sunk, no auricular lobules; smooth lamellae beneath finger IV and toe IV 10–11and 18–20, respectively; two enlarged precloacal scales; hemipenes smooth, short, symmetrical, and forked near the tip, each lobe ended with a small papilla; no dorsal pattern in male; female with black interruptive vertebral line.  Description of holotype.Adult male; SVL 58.5 mm; snout short and obtuse; lower eyelid with an undivided transparent disc; body rather robust; tail regenerated; tympanum deeply sunk with a prominent oblique edge; limbs pentadactyl, toes reach to fingers when limbs adpressed. Head scalation smooth; rostral convex, distinctly visible from above, in broad contact with frontonasal, broader than long ( 2.5 mmwidth, 1.3 mmheight); no supranasals; prefrontals in broad contact with one another; 4 supraoculars; a pair of frontoparietals, shorter than frontal; frontal narrowing posteriorly, longer than wide, bordered laterally by first two supraoculars, anteriorly by prefrontals, and posteriorly by frontoparietals, a little shorter than frontoparietals and interparietal together ( 3.4 mmvs. 3.8 mm); frontoparietals in contact with the second to fourth supraoculars; parietals in contact posteriorly, behind the interparietal; a pair of nuchals; seven supralabials on both sides, fifth below center of the eye, sixth largest; 2 loreals; nostril in center of nasal, in contact with the first supralabial, rostral, anterior loreal, and frontonasal; 9 supraciliaries on right side and 10 on left side, first largest; 2 enlarged anterior temporals, lower one overlapping upper one and in contact with sixth and seventh supralabials; 3 posterior temporals, lower one overlapping upper one ( Figure 3); 6 infralabials, first two in contact with postmental; 3 pairs of chin shields, first pair medially in contact with each other. Dorsal scales smooth, not larger than lateral and ventral scales, ten rows on the back; 34 midbody scale rows; 71 paravertebral scales; ventral scales smooth, in 68 rows; subcaudal scales on the original part of tail not enlarged; 10 and 18 smooth lamellae beneath finger IV and toe IV, respectively; two enlarged precloacal scales, left scale overlapping right one.  Hemipenes. Fully everted hemipenes short, smooth, symmetrical, and forked near the tip with 2 smooth lobes; small papilla at the end of each lobe. Clear sulcus spermaticus starts from base, divides into two branches at fork, extending through two lobes and ending at the tip of each papilla. No regular transversal shallow grooves on body of lobe ( Fig. 4).   FIGURE 3.Holotype of  Scincella badenensis  sp. nov., ITBCZ 5966. A, living specimen; B&C, drawings of lateral and dorsal views of head, respectively.  Coloration. In life, overall dorsal and lateral coloration dark brown with dark blotches that collect to form an interrupted lateral band on upper part of lateral and extend from neck to posterior part of flank; dorsum without black dots, spots or blotches; lateral side and lower part of neck orange to brown; venter yellow to white. Free margin of upper eyelid orange and margin of lower eyelid yellow. Eyes with black round pupil and yellow iris. In preservation, color fades; orange faded to cream or white; overall dorsal and lateral coloration black to dark brown; venter cream except for regenerated part of the tail, which is dark brown; iris became black and pupil became white.  Variation. Table 3summarizes variation in size and scalation of the type series. Most of the morphological characters of paratypesagree with those of the holotype; the following characters are variable: (1) midbody scale rows: vary from 32 ( ITBCZ5878) to 36 ( ITBCZ5967 and 6262); (2) paravertebral and ventral scale rows: range from 67 to 71 and from 68 to 73, respectively; (3) posterior temporals: ITBCZ5878, 5965, 5967, and 5993 have three posterior temporals on both sides, ITBCZ5879 has three posterior temporals on right side; (4) nuchals: ITBCZ5879 and 5993 have only one nuchal scale while ITBCZ5965 has none; (5) supralabials: ITBCZ5879 has 8 scales with sixth below the center of eye on both sides; (6) relative position of precloacal scales: ITBCZ5879 and 5967 have the right scale overlapping the left one; and (7) pattern: ITBCZ5879 and 5993 have interrupted vertebral line formed by black dots and denser dorsolateral bands with black blotches. Other minor variations are shown in Table 3.   FIGURE 4.Fresh hemipenes of the holotype ITBCZ 5966 of  Scincella badenensis  sp. nov.in sulcate and asulcate views.  Natural history.All specimens were collected in rocky areas with rotting leaves, elevations between 74 mand 810 ma.s.l. in both dry and wet seasons.  Scincella badenensis  sp. nov.was usually observed to be active in daytime on rocky walls (approx. 2 mheight) or on surface of rotting leaf layer in caves or between rocks. Sympatric skinks are  Sphenomorphus maculatus(Blyth),  Lygosoma bowringii(Gunther),  Eutropis multifasciata(Kuhl), and  Lipinia vittigera(Boulenger).  Sexual dimorphism.Males are larger than females ( SVLto 64.4 mmvs. 53.8 mm) and have pure dorsum (without vertebral line or dorsal dots) as well as a pale dorsolateral band formed by sparse black blotches while females have interruptive black vertebral line and bold and dense dorsolateral band.  Distribution.The new species is currently known only from Ba Den Mountain, Tay Ninh Province, southern Vietnam( Fig. 1). It was observed to occur from the base to the top of the mountain.  Etymology. The specific epithet  badenensisis a toponym derived from the Ba Den Mountain where the new species was discovered. We recommend “Baden ground skink”, “Thằn lằn cổ bà đen”, and “Rắn mối bà đen” as the common English, Vietnamese, and local names of the new species, respectively. 2423610559 2017-06-25 ITBCZ Sang N. Nguyen & Vu D. H. Nguyen Vietnam 74 11.367111 Ba Den Mountain 1 106.173996 5 278 ITBCZ 5966 1 Tay Ninh holotype 2423610563 2017-03-24 ITBCZ Nguyen & Vu 130 11.370694 Ba Den Mountain 1 106.179245 5 278 ITBCZ 5878, ITBCZ 5879 1 paratype 2423610561 2017-06-25 ITBCZ Sang N. Nguyen & Vu D. H. Nguyen Vietnam 74 11.367111 Ba Den Mountain 1 106.173996 5 278 ITBCZ 5965, ITBCZ 5967 1 Tay Ninh paratype 2423610562 2017-06-25 ITBCZ Vietnam 254 11.36975 1 106.16636 5 278 ITBCZ 5993 1 Tay Ninh paratype 2423610560 2018-01-22 ITBCZ Vietnam 810 11.378305 Figs 5 278 ITBCZ 6262 2 1 1 Tay Ninh paratype