Achalinus emilyae, 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 : 260-265

publication ID	https://doi.org/ 10.11646/zootaxa.4590.2.3
publication LSID	lsid:zoobank.org:pub:3302E889-CDCF-4C0C-AFBE-BD287AFBD15E
persistent identifier	https://treatment.plazi.org/id/314D4322-1551-6344-FF28-D712FC0BFE04
treatment provided by	Plazi
scientific name	Achalinus emilyae
status	sp. nov.

Treatment

Achalinus emilyae sp. nov.

( Figs. 8–10 View FIGURE 8 View FIGURE 9 View FIGURE 10 )

Holotype. IEBR 4465 (Field no. 5/2016 KT 10 ), a female, from Dong Son-Ky Thuong Nature Reserve (21°10.15’N, 107°9.58’E, at an elevation of 348.5 m above sea level), Hoanh Bo District, Quang Ninh Province, Vietnam, collected by M. van Schingen and D.K.T. Pham on 5 May 2016. GoogleMaps

Paratype. VNMN 1334 View Materials , an adult female, from Suoi Tuyen , Bac Giang Province (at an elevation between 320 and 400 m above sea level), collected by T. Ziegler and T. T. Nguyen on 24 June 2010 (listed as A. rufescens in Hecht et al. 2013: 547 –548) .

Diagnosis. A species of the genus Achalinus , characterized by a combination of the following characters: 1) maxillary teeth 27 or 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 5; 6) mental separated from anterior chin shields; 7) two anterior temporals, only the upper one in contact with eye, and two posterior temporals; 8) dorsal scales in 23–23–23 rows, keeled; 9) ventrals in females 157–161; 10) subcaudals in females 63, unpaired; 11) a total length of at least 519.5 mm (with a maximum tail length of 95.1 mm, and a tail/total length ratio of 0.18 in females); 12) dorsum iridescent pale yellowish brown with a dark longitudinal mid-dorsal stripe.

Description of holotype. Total length 415+ mm (SVL 360 mm and TaL 55+ mm); body slender, cylindrical; head slightly distinct from neck, dorsally covered with large shields; eye small, with vertically subelliptic pupil; maxillae with ca. 27 or 28 equal sized and curved teeth each.

Rostral small, triangular, slightly visible from above; suture between the internasals longer than that between the prefrontals; 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 one small scale; second pair of nuchals about 2/3 the size than first pair; one loreal, wider than high, extending from the nasal to the eye; one supraocular; two anterior temporals, elongated, upper one smaller, only uppermost in contact with eye, and two posterior temporals each; 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 five infralabials; first pair of infralabials in contact with each other; first three infralabials in contact with the first pair of chin shields; posterior pair of chin shields smaller, laterally in contact with third and fourth infralabials.

Dorsal scales elliptical, keeled from the neck region onwards; 23 scale rows at midbody, those of the outer row enlarged; 23 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 161, distinct, laterally rounded (potential preventrals included); subcaudals 34+, unpaired; precloacal entire; tail long.

The ethanol-preserved holotype is greyish brown above, with the vertebral region being somewhat darker; 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.

In life, the dorsum is iridescent pale yellowish brown with a dark greyish brown longitudinal mid-dorsal stripe on the body; the dorsal tail surface is greyish brown.

Variation. For scalation details of the type series see Table 4 View TABLE 4 .

Comparisons. Achalinus emilyae sp. nov. can be differentiated from the remaining Achalinus representatives from Vietnam by having the internasal suture being distinctly longer than that between the prefrontals, loreal not being fused with the prefrontal, only one anterior temporal in contact with the eye, five infralabials, different maxillary teeth, ventral and subcaudal, as well as dorsal scale row counts, and the presence of a dark mid-dorsal stripe (see Table 5 View TABLE 5 ).

Achalinus emilyae sp. nov. differs from A. ater in having 5 versus 6 infralabials, and a pale yellowish brown dorsum with a dark mid-dorsal stripe versus a uniform black or dark brown dorsal pattern in A. ater .

Achalinus emilyae sp. nov. differs from A. juliani in having 5 versus 6 infralabials, only one anterior temporal in contact with the eye (versus two), fewer dorsal scale rows in the anterior part of the body (23 versus 25), fewer ventrals in females (157–161 versus 179), fewer subcaudals in females (63 versus 77), and by the presence of a dark mid-dorsal stripe.

Achalinus emilyae sp. nov. differs from A. rufescens by having more ventrals in females (157–161 versus 148–158), more subcaudals in females (63 versus 54–61), more maxillary teeth, and a pale yellowish brown dorsum with a dark mid-dorsal stripe versus a uniform red, brown or grey dorsum in A. rufescens .

Achalinus emilyae sp. nov. differs from A. spinalis by the internasal suture being distinctly longer than that between the prefrontals (versus as long as or shorter), in having 5 versus 6 infralabials, more subcaudals in females (63 versus 39–54), and by having more maxillary teeth.

Achalinus emilyae sp. nov. differs from A. timi in having 5 versus 6 infralabials, the loreal not being fused with the prefrontal, and by different dorsal scale row counts (23–23–23 versus 25–25–23).

Achalinus emilyae 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, 23–23–23 versus 25–29 – 25–27 – 25 dorsal scale rows, and more maxillary teeth (27–28 versus 14–17); in addition, Achalinus emilyae sp. nov. can be distinguished from A. f. formosanus by having fewer ventrals in females (157–161 versus 164–184) and by the presence of 5 versus 6–7 infralabials.

Achalinus emilyae sp. nov. differs from A. hainanus by having 2 versus 1 anterior temporals, fewer ventrals (157–161 versus 165–168), fewer subcaudals (63 versus 67–69), and a pale yellowish brown dorsum with a dark mid-dorsal stripe versus body with metal glow in A. hainanus .

Achalinus emilyae sp. nov. differs from A. jinggangensis by 5 versus 6 infralabials, loreal not being fused with prefrontal, by having more maxillary teeth, and a pale yellowish brown dorsum with a dark mid-dorsal stripe versus a uniform bluish black dorsum in A. jinggangensis .

Achalinus emilyae 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 (23–23–23 versus 21–23 – 19–23 – 19), and by having more maxillary teeth.

Achalinus emilyae 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), by 5 versus 6 infralabials, fewer midbody dorsal scale rows (23 versus 25), fewer ventrals in females (157–161 versus 172–185), more subcaudals in females (63 versus 52–58), keeled body scales (versus smooth on anterior part of body), and a pale yellowish brown dorsum with a dark mid-dorsal stripe versus a black dorsum in A. niger .

Achalinus emilyae sp. nov. differs from A. werneri by the internasal suture being distinctly longer than that between the prefrontals (versus almost as long as), by 5 versus 6 infralabials, by having fewer ventrals in females (157–161 versus 174–191), and fewer subcaudals in females (63 versus 67–85).

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

Distribution. The new species currently is only known from Quang Ninh and Bac Giang provinces, northeastern Vietnam ( Fig. 12 View FIGURE 12 ).

Natural history. The holotype was found at night (22:24) nearby a forest stream. The paratype was likewise found at night (ca. 23:00) on a forest path nearby a stream ( Fig. 11 View FIGURE 11 ).