A sheep in wolf's clothing: Elaphe xiphodonta sp. nov. (Squamata, Colubridae) and its possible mimicry to Protobothrops jerdonii

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 xiphodontasp. 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.