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| Elaphe xiphodonta Qi, Shi, Ma, Gao, Bu, Grismer, Li & Wang, 2021 秦皇锦蛇 || Qin Emperor Rat Snake or Blade-teethed Rat Snake |
Abstract
Based on combined morphological and osteological characters and molecular phylogenetics, we describe a new species of the genus Elaphe that was discovered from the south slope of the Qinling Mountains, Shaanxi, China, namely Elaphe xiphodonta sp. nov. It is distinguished from the other congeners by a combination of the following characters: dorsal scales in 21-21-17 rows, the medial 11 rows keeled; 202–204 ventral scales, 67–68 subcaudals; two preoculars (including one subpreocular); two postoculars; two anterior temporals, three posterior temporals; reduced numbers of maxillary teeth (9+2) and dentary teeth (12); sharp cutting edges on the posterior or posterolateral surface of the rear maxillary teeth and dentary teeth; dorsal head yellow, three distinct markings on the head and neck; a distinct black labial spot present in supralabials; dorsum yellow, 46–49 complete (or incomplete) large black-edged reddish brown blotches on the body and 12–19 on the tail, two rows of smaller blotches on each ventrolateral side; ventral scales yellow with mottled irregular black blotches, a few irregular small red spots dispersed on the middle of the ventral. Based on molecular phylogenetic analyses, the new species forms the sister taxon to E. zoigeensis. The discovery of this new species increases the number of the recognized species in the genus Elaphe to 17.
Keywords: Colubrid, morphology, osteology, Qinling Mountains, taxonomy
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| Figure 2. Detailed pholidosis of the head of the holotype (SYS r002534) of Elaphe xiphodonta sp. nov. Photos by Shuo Qi, illustrated by Xue-Man Zheng. |
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| Figure 1. General view of the holotype (SYS r002534) of Elaphe xiphodonta sp. nov. in life. Photo by Shuo Qi. |
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| Figure 3. Comparison between Elaphe xiphodonta sp. nov. and sympatric Protobothrops jerdonii in different age stages A adult Elaphe xiphodonta sp. nov. (SYS r002534, holotype) B adult Protobothrops jerdonii C juvenile E. xiphodonta sp. nov. (IVPP OV 2721, paratype), road-killed specimen D juvenile P. jerdonii specimen in preservative. The black arrow points to the labial spot. Photos A, B, D by Shuo Qi, photo C by Liang Sun. |
Elaphe xiphodonta sp. nov.
Diagnosis: Elaphe xiphodonta sp. nov. can be differentiated from its congeners by the combination of the following morphological characters: (1) medium body size , SVL 785 mm in single adult female; (2) dorsal scales in 21-21-17 rows, the medial 11 rows keeled; (3) supralabials seven or eight, third/fourth (right) or fourth/fifth (left) in contact with eye, infralabials 9 or 10; (4) ventral scales 202–204; (5) subcaudals 67–68; (6) loreal single, not in contact with eye, not in contact with internasals; (7) two preoculars (including one subpreocular), two postoculars; (8) two anterior temporals, three posterior temporals; (9) precloacal plate divided; (10) reduced teeth number in maxilla and dentary bones (MT 9+2, DT 12; (11) sharp edges on the posterior or posterolateral surface of the rear MT and DT; (12) top of head yellow, three distinct markings on head and neck; (13) a distinct black labial spot present on supralabials; (14) ground color of dorsum yellow, 46–49 entire (or incomplete) reddish brown blotches with black edges on body and 12–19 similarly colored spots on tail; (15) ventral surface of body yellow with mottled irregular black blotches, a few irregular small red spots dispersed on middle of ventral scales.
Etymology. The specific epithet “xiphodonta” of the new species comes from the Ancient Greek “ξίφοσ (ksίfos, refer to ‘knife’ or ‘blade’)” and “δοντι (dónti, refer to ‘tooth’)”, meaning “blade-shaped teeth”, indicating that the new species has unique blade-shaped MT and DT (Figs 5, 6), which differs from the inconspicuous dental specializations (all teeth are cone-shaped) in its congeners. We suggest the Chinese formal name as “秦皇锦蛇” (Qín Huáng Jǐn Shé), which derived from Qin Shi Huang (personal name: Ying Zheng or Zhao Zheng; 259 BC–210 BC), the founder of the Qin dynasty and the first emperor of unified China, whose territory including the distribution range of Elaphe xiphodonta sp. nov. The English name is suggested as “Qin Emperor Rat Snake” or “Blade-teethed Rat Snake”.
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| Figure 7. Comparisons of general morphological characteristics with its congeners in China A Elaphe xiphodonta sp. nov. (SYS r002534, holotype), Ningshaan, Shaanxi, by Shuo Qi B E. anomala, Benxi, Liaoning, by Shuo Qi C E. bimaculata, Hong’an, Hubei, by Chong-Jian Zhou D E. cantoris, Bomê, Tibet, by Jing-Song Shi E E. carinata, Mentougou, Beijing, by Jing-Song Shi F E. davidi, Benxi, Liaoning, by Jing-Song Shi G E. dione, Yongdeng, Gansu, by Shuo Qi H E. hodgsonii, Gyirong, Tibet, by Shuo Qi I E. moellendorffi, Chongzuo, Guangxi, by Jia-Jun Zhou J E. schrenckii, Baishan, Jilin, by Shuo Qi K E. taeniura from Hangzhou, Zhejiang, by Wei-Liang Xie L E. zoigeensis, Jiuzhaigou, Sichuan, by Jin-Wang. |
Shuo Qi, Jing-Song Shi, Yan-Bo Ma, Yi-Fei Gao, Shu-Hai Bu, L. Lee Grismer, Pi-Peng Li and Ying-Yong Wang. 2021. A Sheep in Wolf's Clothing: Elaphe xiphodonta sp. nov. (Squamata, Colubridae) and Its Possible Mimicry to Protobothrops jerdonii. ZooKeys. 1048: 23-47. DOI: 10.3897/zookeys.1048.65650
