Taxonomic reassessment of the Lycodon rufozonatus species complex (Serpentes, Colubridae), with re-evaluation of Dinodon rufozonatum walli, and description of a new species from north-central Vietnam.

The Red-banded Wolf Snake, Lycodon rufozonatus Cantor, 1842 has a complex taxonomic history. In this study, an integrative taxonomic approach is applied, incorporating morphological analyses, cytochrome b mitochondrial gene sequencing, and a re-examination of available type material to clarify the longstanding taxonomic uncertainties within Lycodon rufozonatus species complex. Our findings restrict the distribution of Lycodon rufozonatus to mainland China, Taiwan, the Korean Peninsula, Russia (southern Primorsky Krai), Japan (Tsushima Islands, Nagasaki), and northeastern Vietnam. Additionally, Dinodon rufozonatum walli Stejneger, 1907, previously considered a subspecies, is elevated to full species status as Lycodon walli stat. nov., endemic to the Miyako and Yaeyama Islands, Okinawa, Japan. Furthermore, a new cryptic species is described from north-central Vietnam, Lycodon duytan sp. nov., which is distinguished from L. rufozonatus and L. walli stat. nov. by differences in body scalation, colouration, and the number of keeled dorsal scales. Our findings highlight the underestimated diversity within Lycodon and contribute to a more refined understanding of its taxonomy. This study increases the total number of recognised Lycodon species to 78, underscoring the importance of integrative approaches in resolving taxonomic complexities within the genus.