We investigate the phylogenetic relationships of two poorly known Natricinae, Parahelicops and Pararhabdophis, for which we obtained nucleotide sequence data from one mitochondrial gene (cytochrome b) and three nuclear genes (CMOS, NT3, and RAG1). Maximum parsimony, maximum likelihood, and combined and partitioned Bayesian analyses suggest that both Parahelicops and Pararhabdophis are embedded within the genus Hebius. To align classification with phylogeny, we synonymize Parahelicops and Pararhabdophis with Hebius.

Cyrtodactylus is the most diverse genus of the family Gekkonidae and the world’s third largest vertebrate genus. The number of species has increased more than fourfold over the last two decades. Indochina, especially Vietnam and Laos, has witnessed a surge in new species discoveries over the last three decades. The species number reported from Laos and Vietnam has remarkably increased from five in 1997 to 71 species in 2021. However, within the genus, several taxonomic issues have not yet been fully resolved. Based on recently collected samples from Laos and Vietnam, we conducted a comprehensive molecular review of Cyrtodactylus occurring in Laos and Vietnam. Our molecular analysis with support from morphological comparisons showed that C. thuongae is a junior synonym of C. dati and C. rufford is a junior synonym of C. lomyenensis. In total, 68 described species distributed in Laos and Vietnam are undisputed with strong support from both molecular and morphological evidence. On the other hand, the molecular analyses revealed that there are at least seven undescribed species in Vietnam and Laos, one in the C. angularis group, one in the C. chauquangensis, and five in the C. irregularis group. This number will likely increase significantly, as previous work suggested that the C. angularis and C. irregularis groups harbor three and six unnamed lineages, respectively. Based on survey gaps identified in our study, it is clear that additional new species will be discovered in poorly studied regions of central Vietnam and northern and southern Laos. As many species in the genus are facing high extinction risks, several undescribed populations might already be severely threatened by human activities in both countries. Therefore, urgent taxonomic research is needed before conservation assessments of newly discovered taxa can be undertaken to protect them from anthropogenic threats.

Tóm tắt: Cyrtodactylus là một trong những nhóm có mức độ đa dạng cao nhất trong họ tắc kè (Gekkonidae) ở Việt Nam. Năm 1997 chỉ có ba loài được ghi nhận phân bố ở Việt Nam, và cho tới nay 38 loài đã được mô tả và ghi nhận. Các nghiên cứu gần đây cho thấy một số loài có hình thái rất giống nhau dẫn tới việc phân loại các loài thằn lằn ngón đến nay vẫn chưa rõ ràng. Dựa trên các mẫu thu từ 24 tỉnh trên cả nước, chúng tôi đã tiến hành nghiên cứu toàn diện về mối quan hệ di truyền cho tất cả các loài đã được mô tả ở Việt Nam dựa trên trình tự của một phân đoạn gen COI. Kết quả cho thấy loài C. paradoxus là loài đồng danh của loài C. condorensis và loài C. thuongae là loài đồng danh của C. dati. Ngoài ra, kết quả nghiên cứu cũng cho thấy các loài thuộc giống Cyrtodactylus ở Việt Nam tập hợp thành 4 nhóm: nhóm A gồm các loài C.

Based on morphological and molecular analyses, we herein describe a new species of Achalinus from northern Vietnam. Achalinus quangi sp. nov. differs from its sister taxon, A. emilyae, and other members of the genus Achalinus by at least 4% in terms of genetic divergence based on fragments of the mitochondrial COI and Cytb genes and a combination of the following morphological characters: (1) maxillary teeth 27–29; (2) suture between the internasals distinctly longer than that between the prefrontals; (3) loreal not fused with prefrontal, extending from the nasal to the eye; (4) supralabials six; (5) infralabials five; (6) postocular absent, temporals 2+2, only the upper one in broad contact with eye; (7) dorsal scales in 25(23)–23–23(21) rows, keeled; (8) ventrals 139–141 in males, 141–154 in females; (9) subcaudals 75–84 in males, 69 in the female, all unpaired; (10) cloacal entire; (11) dorsum reddish brown to brown. Achalinus quangi sp. nov. consists of two subclades, the first one occurring on the northern side of the Da River in Son La and Tuyen Quang provinces and another subclade found on the southern side in Thanh Hoa, Nghe An, and Ha Tinh provinces. These two subclades are separated from each other by 1.8 to 2.3% genetic divergence and are slightly differing in ventral scalation.