Achalinus juliani, Ziegler & Nguyen & Pham & Nguyen & Pham & Schingen & Nguyen & Le, 2019

Ziegler, Thomas, Nguyen, Truong Quang, Pham, Cuong The, Nguyen, Tao Thien, Pham, Anh Van, Schingen, Mona Van, Nguyen, Tham Thi & Le, Minh Duc, 2019, Three new species of the snake genus Achalinus from Vietnam (Squamata: Xenodermatidae), Zootaxa 4590 (2), pp. 249-269 : 253-255

publication ID	https://doi.org/ 10.11646/zootaxa.4590.2.3
publication LSID	lsid:zoobank.org:pub:3302E889-CDCF-4C0C-AFBE-BD287AFBD15E
DOI	https://doi.org/10.5281/zenodo.5586666
persistent identifier	https://treatment.plazi.org/id/314D4322-155E-6352-FF28-D2AEFDABF827
treatment provided by	Plazi
scientific name	Achalinus juliani
status	sp. nov.

Treatment

Achalinus juliani sp. nov.

( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )

Holotype. IEBR A.2018.8 (Field no. CB 2014.18 ), an adult male, from forest of Duc Quang Commune (22°43.084’N, 106°39.653’E, at an elevation of 477 m above sea level), Ha Lang District , Cao Bang Province, northern Vietnam, collected by C.T. Pham on 14 June 2014. GoogleMaps

Paratypes. IEBR A.2018.9 (Field no. CB 2014.19 ), a female, from Phia Oac-Phia Den National Park (22°36.147’N, 105°52.726’E, at an elevation of 1461 m above sea level), Nguyen Binh District, Cao Bang Province, northern Vietnam, collected by T.H. Pham on 24 May 2014 GoogleMaps ; VNMN 0 6924 (Field no. TAO 766 ), an adult male, from forest of Thanh Cong Commune within Phia Oac-Phia Den National Park (22°60.556’N, 105°87.530’E, at an elevation of 1590 m above sea level), Nguyen Binh District, Cao Bang Province, northern Vietnam, collected by T.T. Nguyen on 10 May 2010 .

Diagnosis. A species of the genus Achalinus , characterized by a combination of the following characters: 1) maxillary teeth 28; 2) suture between internasals distinctly longer than that between the prefrontals; 3) internasal not fused to prefrontal; 4) loreal not fused with prefrontal; 5) infralabials 6; 6) mental separated from anterior chin shields; 7) two elongated anterior temporals, in contact with eye, and two posterior temporals; 8) dorsal scales in 25–23–23 rows, keeled; 9) ventrals 173–179; 10) subcaudals 77–91, unpaired; 11) a total length of at least 413 mm (with a maximum tail length of 109 mm, and a tail/total length ratio of 0.22–0.37); 12) dorsum in preservative reddish to greyish brown above, the lower and posterior head sides paler; venter greyish cream, with the underside of the tail being somewhat darker.

Description of holotype. Total length 355 mm (SVL 260 mm and TaL 95 mm); tail long, tail/total length ratio 0.365; body slender, cylindrical; head length 8.9 mm (from tip of snout to posterior margin of parietal); head slightly distinct from neck, dorsally covered with large shields; eye small, with vertically subelliptic pupil; left maxilla with 28 equally sized and curved teeth.

Rostral small, triangular, slightly visible from above; suture between the internasals (1.4 mm) longer than that between the prefrontals (0.9 mm); nostril in the anterior part of the nasal; frontal pentagonal, slightly broader than long, pointed backwards, much shorter than the parietals; each parietal bordered by an elongated nuchal; nuchals separated from each other behind parietals by two small scales; second pair of nuchals about half the size than first pair; one loreal, distinctly wider than high, extending from the nasal to the eye; one supraocular; two anterior temporals, elongated, upper one smaller, both in contact with eye, and two elongated posterior temporals; supralabials six, the first smallest, fourth and fifth in contact with the eye, sixth longest; third and fourth in contact with the loreal; one mental, followed by six infralabials; first pair of infralabials in contact with each other; first four infralabials in contact with the first pair of chin shields; posterior pair of chin shields smaller, laterally in contact with fourth and fifth infralabials.

Dorsal scales elliptical, keeled from the neck region onwards, 23 scale rows at midbody, those of the outer row enlarged, 25 scales round the anterior part of the body (one head length behind head), and 23 dorsal scale rows at posterior body (one head length before vent); ventrals 169 (plus one preventral), distinctly rounded laterally; subcaudals 91, unpaired, plus tail tip; cloacal entire.

The ethanol-preserved holotype greyish brown above, the lower and posterior head sides being paler; venter greyish cream, with the underside of the tail being somewhat darker and the chin region somewhat paler; infralabial and chin shields light greyish brown. Ventrals and subcaudals anteriorly and laterally darker.

Variation. For scalation details of the paratypes see Table 3 View TABLE 3 . In addition, the nuchals of the female paratype IEBR A.2018.9 are separated from each other behind the parietals by four small scales and those of the male paratype VNMN 0 6924 by two large, two medium sized and a small scale. Furthermore, in the paratype VNMN 0 6924 the posterior pair of chin shields on the left side is in contact with third and fourth infralabials laterally. The hemipenes are basally everted in the specimen VNMN 0 6924.

Comparisons. Achalinus juliani sp. nov. can be differentiated from the remaining Achalinus representatives from Vietnam by having more subcaudals, more dorsal scale rows on anterior part of the body, more ventrals, more infralabials, and a longer internasal suture (see Tables 3 View TABLE 3 , 5 View TABLE 5 ).

Achalinus juliani sp. nov. differs from A. ater in having more dorsal scale rows in the anterior part of the body (25 versus 21–23) and more subcaudals (77–91 versus 47–70).

Achalinus juliani sp. nov. differs from A. rufescens by having more infralabials (6 versus 5), more ventrals (163–179 versus 131–158), more subcaudals (77–91 versus 54–82), and more maxillary teeth.

Achalinus juliani sp. nov. differs from A. spinalis by the internasal suture being distinctly longer than that between the prefrontals (versus as long as or shorter), more dorsal scale rows in the anterior part of the body (25 versus 21–24), more subcaudals (77–91 versus 39–67), by lacking a black mid-dorsal line, and by having more maxillary teeth.

Achalinus juliani sp. nov. differs from A. formosanus by having the internasal suture distinctly longer than prefrontal suture (versus internasal suture almost as long as prefrontal suture), by the loreal not being fused with prefrontal, fewer dorsal scale rows (25–23–23 versus 25–29 – 25–27–25), more maxillary teeth (28 versus 14–17), and by lacking a black mid-dorsal line; in addition, Achalinus juliani sp. nov. can be distinguished from A. f. formosanus by having more subcaudals (77–91 versus 61–83), and from A. f. chigirai by having fewer subcaudals (77–91 versus 96–97).

Achalinus juliani sp. nov. differs from A. hainanus by having 6 versus 5 infralabials, 2 versus 1 anterior temporal, more dorsal scale rows in the anterior part of the body (25 versus 23), and more subcaudals (77–91 versus 67–69).

Achalinus juliani sp. nov. differs from A. jinggangensis by loreal not being fused with prefrontal, having more ventrals (163–179 versus 156–164), more subcaudals (77–91 versus 51–64), and more maxillary teeth.

Achalinus juliani sp. nov. differs from A. meiguensis by mental being separated from anterior chin shields, internasal not fused to prefrontal, by different dorsal scale row counts (25–23–23 versus 21–23 – 19–23 – 19), by having more subcaudals (77–91 versus 39–62), and by having more maxillary teeth.

Achalinus juliani sp. nov. differs from A. niger by the internasal suture being distinctly longer than that between the prefrontals (versus almost as long as or shorter), fewer midbody dorsal scale rows (23 versus 25), more subcaudals (77–91 versus 52–72), and keeled body scales (versus smooth on anterior part of body).

Achalinus juliani sp. nov. differs from A. werneri by the internasal suture being distinctly longer than that between the prefrontals (versus almost as long as), and by lacking a black mid-dorsal line and a dark subcaudal streak.

Etymology. We name this species after Julian L. Ziegler. As common name we propose Julian’s Burrowing Snake.

Distribution. The new species currently is only known from two localities within Cao Bang Province, northeastern Vietnam ( Fig. 12 View FIGURE 12 ).

Natural history. Specimens were found between 20:00 and 22:00 h on forest paths. The surrounding habitat was secondary forest of large, medium and small hardwoods mixed with shrubs and vines. Air temperature at the sites were 25.4–32.6 o C and relative humidity 65–80%. The new species was found in different habitat types: lowland forest in Phia Oac-Phia Den National Park and limestone karst forest in Ha Lang District, at elevations from 470 to 1460 m above sea level.