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| Desmoxytes chaofa & D. sirindhornae Srisonchai, in Srisonchai, Srikampha, Benchapong et Panha, 2025. Tropical Natural History. Supplement 8; |
Abstract
Recent field surveys in northern Thailand led to the discovery of two remarkable new species of dragon millipede in the genus Desmoxytes Chamberlin, 1923. Using an integrative approach that combined morphological and molecular data, we confirmed the validity of these species, herein described as Desmoxytes chaofa Srisonchai, sp. nov. from Mae Hong Son Province and Desmoxytes sirindhornae Srisonchai, sp. nov. from Tak Province. To assess their systematic position and relationships, we conducted morphological examinations and reconstructed the phylogeny based on three gene fragments (COI, 16S rRNA, and 28S rRNA). Phylogenetic analysis supports the validity of these two new species, with genetic divergence in the COI gene clearly distinguishing them from congeners, ranging from 10.67–18.67% for D. chaofa Srisonchai, sp. nov. and 10.05–17.91% for D. sirindhornae Srisonchai, sp. nov. (mean = 14.71%). Notably, the phylogenetic tree aligns well with morphological characters, particularly those of the gonopod. Desmoxytes chaofa Srisonchai, sp. nov. is closely related to D. octoconigera Srisonchai, Enghoff & Panha, 2018, while D. sirindhornae Srisonchai, sp. nov. clusters together with D. des Srisonchai, Enghoff & Panha, 2016, both pairs exhibiting similarities in body colouration and gonopod telopodite. Based on current data, these two species are considered as narrow endemics and are restricted to limestone rock wall habitats. Complete morphological illustrations of the two new species and a distribution map of all Desmoxytes species are provided.
Keywords: biodiversity, evolution, karst, Southeast Asia, systematics
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| Photographs of live specimens and habitat of Desmoxytes chaofa sp. nov. (paratypes, MZKKU-MYR0014).(A) male paratype; (B) female paratype; (C) mating couple; (D, E) limestone habitat. Scale bars in centimetres. |
Class Diplopoda de Blainville in Gervais, 1844
Order Polydesmida Leach, 1815
Family Paradoxosomatidae Daday, 1889
Genus Desmoxytes Chamberlin, 1923
Desmoxytes chaofa Srisonchai, sp. nov.
Etymology.–The originally Thai term ‘chaofa’, a noun in apposition, signifies a royal princess of the Thai monarchy and is bestowed in honour of Her Royal Highness Princess Maha Chakri Sirindhorn. Renowned for her dedication to biodiversity research and environ-mental conservation, she has made significant contributions to these fields. With a profound passion for science and nature, she has actively supported research initiatives that deepen the understanding and preservation of Thailand’s rich biodiversity.
Etymology.–The originally Thai term ‘chaofa’, a noun in apposition, signifies a royal princess of the Thai monarchy and is bestowed in honour of Her Royal Highness Princess Maha Chakri Sirindhorn. Renowned for her dedication to biodiversity research and environ-mental conservation, she has made significant contributions to these fields. With a profound passion for science and nature, she has actively supported research initiatives that deepen the understanding and preservation of Thailand’s rich biodiversity.
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| Photographs of live specimens and habitat of Desmoxytes sirindhornae sp. nov. (paratypes, MZKKU-MYR0016). (A) male paratype (B) female paratype (C) amorous couple of adults (D, E) limestone habitat. Scale bars in centimetres. |
Desmoxytes sirindhornae Srisonchai, sp. nov.
Etymology.– This species is named in honour of Her Royal Highness Princess Maha Chakri Sirindhorn, whose remarkable contributions have significantly advanced biodiversity research and the preservation of Thailand’s natural heritage for future generations. Her unwavering commitment continues to inspire scientists, conservationists, and the public in efforts to safeguard the nation’s ecosystems. She has played a pivotal role in fostering scientific collaborations, supporting re-search institutions, and encouraging young scholars to pursue ecological and environmental studies. Her dedi-cation spans a wide range of conservation initiatives, including the protection of endangered species, forest conservation, and the promotion of sustainable resource management.
Ruttapon Srisonchai, Khanet Srikampha, Theemaporn Benchapong and Somsak Panha. 2025. Integrative Taxonomy Reveals Two New Dragon Millipede Species in the Genus Desmoxytes Chamberlin, 1923 from Thailand (Diplopoda: Polydesmida: Paradoxosomatidae). Tropical Natural History. Supplement 8; 79-107. DOI: 10.58837/tnh.25.8.266903 [2025-10-14]
