Achalinus timi Ziegler & Nguyen & Pham & Nguyen & Pham & Schingen & Nguyen & Le 2019, sp. nov.
Creators: name: Ziegler, Thomas
name: Nguyen, Truong Quang
name: Pham, Cuong The
name: Nguyen, Tao Thien
name: Pham, Anh Van
name: Schingen, Mona Van
name: Nguyen, Tham Thi
name: Le, Minh Duc
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Xenodermatidae
Achalinus
Achalinus timi

description: Achalinus timi sp. nov.
(Figs. 6–7)
Holotype. IEBR A.2018.10 (Field no. PA.180), adult male, from forest within the Copia Nature Reserve, near Hua Ty Village (21°20.105’N, 103°35.860’E), Co Ma Commune, Thuan Chau District, Son La Province, northern Vietnam, collected by A.V. Pham on 12 May 2014 at an elevation of ca. 1470 m above sea level.
Diagnosis. A species of the genus Achalinus, characterized by a combination of the following characters: 1) maxillary teeth 27; 2) suture between the internasals distinctly longer than that between the prefrontals; 3) loreal fused with prefrontal on each side, with the prefrontal extending towards the supralabials; 4) dorsal scales in 25–25–23 rows, keeled; 5) ventrals 170+1; 6) subcaudals 72, unpaired; 7) a total length of at least 177.9 mm in males (with a tail length of 37.9 mm and a tail/total length ratio of 0.21); 8) dorsum in preservative reddish to greyish brown above, with wide portion of the vertebral region being distinctly darker; the lower head sides are somewhat paler; infralabial and chin shields light greyish brown; venter greyish cream, with the underside of the tail being somewhat darker and the chin region somewhat paler.
Description of holotype. Total length 177.9 mm (SVL 140 mm, TaL 37.9 mm); tail long, tail/total length ratio 0.21; body slender, cylindrical; head length 7.8 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 at least 27 equally sized and curved teeth.
Rostral small, triangular, not visible from above; suture between the internasals (1.7 mm) longer than that between the prefrontals (0.8 mm); nostril in the anterior part of the nasal; frontal pentagonal, slightly broader than long, pointed backwards, much shorter than the parietals; parietals bordered each 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; loreal lacking, prefrontals stretch towards the supralabials; one supraocular; two anterior temporals, only the smaller, upper one in contact with eye, and two elongated posterior temporals; supralabials six, the first smallest, fourth and fifth in contact with the eye, sixth longest; one mental, followed by six 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 fourth and fifth infralabials.
Dorsal scales elliptical, keeled from the neck region onwards, in 25 rows at the anterior part of the body (one head length behind head), 25 scale rows at midbody, the outer row enlarged, and 23 rows at posterior body (one head length before vent); ventrals 170 (plus one preventral) distinct, laterally rounded; subcaudals 72, unpaired; cloacal entire.
The ethanol-preserved holotype is reddish to greyish brown above, with a wide portion of the vertebral region being distinctly darker; the lower head sides somewhat 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.
Comparisons. Achalinus timi sp. nov. lacks a separate loreal scale, which is fused with the prefrontal on each side, with the prefrontal extending towards the supralabials; all remaining Achalinus species known at time to occur in Vietnam (A. ater, A. juliani, A. rufescens, and A. spinalis) have a loreal being separated from the prefrontal by a suture, which is also the case in most other Achalinus species (A. hainanus, A. meiguensis, A. niger, and A. werneri) which thus can be easily distinguished from Achalinus timi sp. nov. Achalinus timi sp. nov. further differs from A. formosanus, A. jinggangensis, A. meiguensis, A. rufescens, and A. spinalis by having more maxillary teeth. For details and further distinguishing characters see Table 5.
Besides different maxillary teeth counts, Achalinus timi sp. nov. can be distinguished from the two subspecies of A. formosanus as follows: from A. f. formosanus by having the internasal suture distinctly longer than prefrontal suture (versus internasal suture almost as long as prefrontal suture) and 25–25–23 versus 29–27–25 dorsal scale rows; and from A. f. chigirai by 23 versus 25 dorsal scale rows at posterior body and by having more ventrals and less subcaudals (170 versus 161–167 ventrals; 72 versus 96–97 subcaudals).
Furthermore, Achalinus timi sp. nov. can be distinguished from A. jinggangensis by having 25 versus 23 dorsal scale rows at midbody, more ventrals and subcaudals (170 versus 156–164 ventrals; 72 versus 51–64 subcaudals, respectively).
Etymology. We name this species after Tim N. Ziegler. As common name we propose Tim’s Burrowing Snake.
Distribution. The new species currently is only known from the type locality in Son La Province, northwestern Vietnam (Fig. 12).
Natural history. The male holotype of Achalinus timi sp. nov. was discovered at 10: 15 in the morning, as a road kill specimen. The surrounding habitat was secondary evergreen forest. Air temperature at the site was 25–30 o C and relative humidity 70–75%.
description: Published as part of 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), pp. 249-269 in Zootaxa 4590 (2) on pages 258-260, DOI: 10.11646/zootaxa.4590.2.3, http://zenodo.org/record/2651878