Pareas mengziensis, Wang & Che & Liu & Li & Jin & Jiang & Shi & Guo, 2020

Wang, Ping, Che, Jing, Liu, Qin, Li, Ke, Jin, Jie Qiong, Jiang, Ke, Shi, Lei & Guo, Peng, 2020, A revised taxonomy of Asian snail-eating snakes Pareas (Squamata, Pareidae): evidence from morphological comparison and molecular phylogeny, ZooKeys 939, pp. 45-64 : 45

Pareas mengziensis sp. nov. Figure 5

Holotype.

YBU 14252, adult female, collected from Mengzi, Yunnan Province, China, at an elevation of 1 900 m above sea level in July 2014.

Paratypes.

Two adult females (YBU 141251 and YBU 15100) and three adult males (YBU 14253, YBU 14288, and YBU 15114) from the same locality and adjacent regions collected in July 2014 and July 2015.

Diagnosis.

(1) solid black marking on back of head extending along whole dorsal of body; (2) single preocular; (3) postocular fused with subocular; (4) loreal not bordering orbit; (5) temporals 2+3+3; (6) prefrontal bordering orbit; (7) three rows of mid dorsal scales slightly enlarged; (8) 3-7 rows of mid dorsal scales keeled; (9) 6-7 supralabials; (10) 8-9 infralabials; (11) 6-7 maxillary teeth; (12) cloaca undivided; (13) ventral scales 167-173; (14) subcaudals 54-61, paired.

Description of holotype.

Female, SVL 426 mm, TL 98 mm, TL/total length 0.187; body elongated; head distinct from neck. Internasals sub-triangular, wider than long; prefrontals sub-rectangular, wider than long, bordering orbits; frontal shield-shaped; one relatively small supraocular; parietals irregular, longer than wide; rostral almost invisible from above, wider than deep; nasals undivided; single loreal, separating from eyes; single preocular; single thin elongated subocular; postocular fused with subocular, supraocular sub-triangular; temporals 2+3+3; seven supralabials, separating from eyes; 8-9 infralabials, anterior-most in contact with opposite between mental and anterior chin-shields, first four in contact with anterior chin-shields; three chin-shields pairs, anterior pairs larger than other two; ventral scales 170; cloaca undivided; subcaudals 54, paired; dorsal scales in 15 rows throughout, three median rows enlarged, 3-7 rows of mid dorsal scales keeled; 6-7 maxillary teeth.

Solid black marking on back of head extending along whole dorsal of body and tail; sides of head light brownish yellow, speckled with small, irregular, dark brown spots; two black spots on each side of head, anterior one on intersection of anterior two temporals and 6th and 7th supralabials, posterior one on middle of 7th supralabial; vertical brownish yellow stripe on neck, eight scales long and 1-2 scales wide; body brownish yellow with numerous irregular black cross-bands on lateral of body, contacting with solid black dorsal of body, some extending to edges of ventral scales; belly light brown with sparse dark brown spots; tail purely black except for first 20 pairs of subcaudals light brown.

Description of paratypes.

The paratypes agree in most respects with the description of the holotype. A comparison of the most important morphological characters is summarized in Suppl. material 3: Appendix S3.

Etymology.

The new species is named after the type locality Mengzi City, Yunnan Province, China. We suggest the common name "Mengzi Snail-eating Snake" in English and "Mengzi Dun-tou-she ( 蒙自钝头蛇)” in Chinese.

Distribution.

This species is currently known only from the type locality Mengzi City, Yunnan, China, in deciduous broad-leaved forest with a subtropical monsoon climate. It is expected to be located in the surrounding plateau regions.

Comparison.

Pareas mengziensis sp. nov. can be distinguished from P. carinatus , P. nuchalis , and P. menglaensis sp. nov. by having one thin elongated subocular (vs. two or three suboculars). It is most similar to P. yunnanensis Mell, 1931, P. niger Pope, 1928, and P. nigriceps in terms of color pattern, but differs from these species by eight or nine infralabials (vs. seven) and three rows of mid dorsal scales enlarged (vs. not enlarged or only one enlarged mid dorsal scale). It differs from the remaining species of Pareas by having a large solid black area on back of head and body.

Figures

Figure 5. Holotype of Pareas mengziensis sp. nov. (YBU 14252). Dorsal (A) and ventral (B) of general views; dorsal (C), ventral (D), and lateral (E) views of the head.