The first record of Calamaria nebulosa Lee, 2021 (Squamata, Calamariidae) from Yunnan Province, China and an expanded morphological description based on newly-collected specimens

Calamaria nebulosa Lee, 2021 was originally described, based on a single female holotype collected in Phongsaly Province, Laos. Until now, this species has been known only from a single specimen and exhibits an extremely restricted geographic distribution. Consequently, its intraspecific morphological variation and biogeography remain poorly understood. Several Calamaria specimens collected during recent field surveys were identified as C. nebulosa using morphological and molecular data, representing a new national record for China. Genetic analyses, based on the mitochondrial cytb gene, confirmed that these specimens clustered within a well-supported C. nebulosa clade, with uncorrected p -distances of 1.2%–1.3% relative to the holotype. Herein, we provide a detailed morphological description of Chinese C. nebulosa specimens and revise the species diagnosis: rostral scale wider than high; the portion of rostral scale visible in dorsal view is approximately half the length of the prefrontal suture; six scales and shields surround the paraparietal scale; preocular scale absent; four supralabials, with the second and third touching the orbit; five infralabials, the first pair separating the mental from the anterior chin-shields; posterior chin-shields meeting only anteriorly; five indistinct dark-brown longitudinal dorsal stripes; ventral surface of tail uniformly yellow and immaculate in preservative; distinct white nuchal collar absent; dorsal scales reduce from six to four rows between the last 1 st and 4 th subcaudal scales; ventrals scales 179-192 in males and 198-206 in females. To date, a total of twelve Calamaria species have been recorded from China.