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