A new Scincella species (Squamata, Scincidae) from the Dabie Mountains, China, with delimitation of its closely related congeners

Previous studies have indicated the polyphyly of Scincella modesta and reported a new record of Scincella vandenburghi in Qingdao, Shandong Province. Furthermore, the research highlighted significant morphological similarities between the Qingdao population of S. vandenburghi and a branch of S. modesta from Hubei, leaving the taxonomic boundaries between these two species unclear. To better understand the relationship between S. modesta and S. vandenburghi , we conducted extensive sampling in the Dabie Mountains, which geographically lie between Qingdao, Ningbo and Yichang. Based on phylogenetic analyses and morphological comparisons, we identify an undescribed species of the genus Scincella from the Dabie Mountains, China and also discover the presence of a population of S. vandenburghi in the same region. Morphological characteristics and molecular phylogenetic analyses indicate that the new species is similar to S. vandenburghi , but clearly distinct from it and other congeners. The new species has the following characteristics: (1) slender body, small size, snout-vent length 24.47–40.60 mm; (2) supraciliaries 6 or 7; (3) midbody scale row counts 28–31; (4) dorsal scales smooth and slightly enlarged, paravertebral scale row counts 55–68, ventral scale row counts 55–64; (5) upper edge of lateral longitudinal stripes relatively wavy, lower edge irregular, covering 2–2.5 scale rows on the trunk; (6) black dorsolateral stripes from posterior corner of eye to lateral side of tail, six rows of dorsal scales in middle; (7) supralabials 7, infralabials 6 or 7; (8) tympanum diameters significantly smaller than palpebral disc diameters; (9) 9–12 enlarged lamellae beneath finger IV and 14–17 beneath toe IV; (10) 3–4 pairs of nuchal scales; (11) when the limbs are pressed down, toes and fingers touch or overlap. Phylogenetic analyses indicate that the population from the Dabie Mountains in Anhui Province, China, represents a new species, with a 3% uncorrected genetic distance in 16S rRNA from its closest relative ( S. vandenburghi ). This discovery brings the total number of Scincella species in China to 19, identifying the known distribution of the genus. We have made preliminary progress in clarifying the relationship between S. vandenburghi and S. modesta ; however, the polyphyletic issues surrounding S. modesta warrant further investigation in future research. Additionally, the distribution patterns and divergence times of the two Scincella species in the Dabie Mountains require further study to gain a more comprehensive understanding.