Saturday, June 17, 2023

[Herpetology • 2023] Achalinus hunanensis • A New Species of Achalinus Peters, 1869 (Serpentes: Xenodermidae) from Hunan Province, China


Achalinus hunanensis 
Ma, Shi, Xiang, Shu & Jiang, 2023

湖南脊蛇 | Hunan Odd-scale Snake | Hunan Burrowing Snake || DOI: 10.3897/zookeys.1166.103055
Photographs by Sheng-Chao Shi.

Abstract
A new species, Achalinus hunanensis sp. nov., is described from middle and western Hunan Province based on the results of molecular systematics and morphological characters. It diverges from known congeners by a significant genetic divergence (p-distance 3.2%–16.9% based on CO1 mitochondrial gene), and it can be distinguished from all known congeners by the following morphological characters: (1) all dorsal scales strongly keeled, 23 rows throughout the body, the outmost one strongly keeled and enlarged; (2) tail relatively short, TaL/TL 0.221 ~ 0.225; (3) maxillary teeth 23; (4) the suture between internasals 2 × as long as that between prefrontals; (5) loreal one, subrectangular, LorH/LorL 0.62 ~ 0.70; (6) supralabials 6, the 4th and 5th touch the eye; (7) the two anterior temporals in contact with eye; (8) ventrals 163–165, subcaudals 69–72, not paired. This raises the number of known species of Achalinus to 24.

Key words: Achalinus hunanensis sp. nov., morphology, phylogeny, divergence time, taxonomy


The holotype (CIB 119039, subadult male) of Achalinus hunanensis sp. nov.
A dorsolateral view B ventral view C right side of middle body view D dorsal head view E left side of head view F right side of head view G ventral head view.
Photographs by Sheng-Chao Shi.

 Achalinus hunanensis sp. nov.
 
Achalinus ater: Shu et al. 2014; Shen et al. 2014; Gao et al. 2022.

Diagnosis: (1) 23 rows of dorsal scales throughout the body, all dorsal scales strongly keeled, and the outmost one strongly keeled and enlarged; (2) tail relatively short, TaL/TL 0.221 ~ 0.225; (3) maxillary teeth 23; (4) the suture between internasals 2 × as long as that between prefrontals; (5) loreal one, subrectangular, LorH/LorL 0.62 ~ 0.70; (6) supralabials six, the 4th and 5th touch the eye; (7) the two anterior temporals in contact with eye; (8) ventrals 163–165, subcaudals 69–72, not paired.
 
Etymology: This new species is named after its known distribution range, which is endemic to Hunan Province. 
The Chinese name is suggested as “湖南脊蛇” (Hú Nán Jǐ Shé) 
and the English name “Hunan Odd-scale Snake” or “Hunan Burrowing Snake” is suggested.


 Shun Ma, Sheng-Chao Shi, Sun-Jun Xiang, Fu Shu and Jian-Ping Jiang. 2023. A New Species of Achalinus Peters, 1869 (Squamata, Xenodermidae) from Hunan Province, China. ZooKeys. 1166: 315-331. DOI: 10.3897/zookeys.1166.103055