Molecular and morphological data uncover a striking new genus of dragon millipedes in Thailand, with alternately long and short legs (Diplopoda, Polydesmida, Paradoxosomatidae)

2025/06/25 by Ruttapon Srisonchai, Henrik Enghoff, Natdanai Likhitrakarn +2 · 1 voice · 2 citations
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Environmental Science · #Amphibian and Reptile Biology #Biology #Clade #Cladistics #Evolutionary biology #Genus #Millipede #Monophyly #Myriapoda #Phylogenetic tree #Spider Taxonomy and Behavior Studies #Subterranean biodiversity and taxonomy #Systematic Entomology #Systematics #Taxonomy (biology) #Zoology

paper · doi:10.1071/is25007

published in Invertebrate Systematics 39(6) (CSIRO Publishing)

openalex publication_date 2025/06/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

The dragon millipedes are a unique and diverse group of diplopods, endemic to limestone habitats in South-east Asia, and yet several new genera and species are still to be discovered. Among these, a recent field survey uncovered several striking specimens featuring alternately long and short legs on each diplosegment, a morphological trait previously unseen in the family Paradoxosomatidae or any other diplopods, except for the genus Pandirodesmus Silvestri, 1932 (family Chelodesmidae). Using mitochondrial (COI , 16S ) and nuclear (28S ) genetic data, alongside detailed morphological analysis in order to confirm their status, we reconstructed phylogenetic trees of dragon millipedes through maximum likelihood and Bayesian inference. The phylogenetic trees strongly support the monophyly of all dragon millipedes, as well as of each nominal dragon millipede genus. The results also revealed the new specimens forming a distinctly separate clade that is closely related to Spinaxytes . Based on these findings, we establish a new monotypic genus of dragon millipedes to accommodate a new species, Alternaxytes bipectinata gen. nov., sp. nov., within the tribe Orthomorphini of the family Paradoxosomatidae. Morphologically, Alternaxytes gen. nov. is characterised by unique gonopodal features and heteropodous legs, suggesting a case example of convergent evolution within Diplopoda. ZooBank: urn:lsid:zoobank.org:pub:E8C1488C-AF69-4F52-9F65-7645C7498D60.

Citations

• MrBayes 3.2: Efficient Bayesian Phylogenetic Inference and Model Choice Across a Large Model Space
• IQ-TREE 2: New Models and Efficient Methods for Phylogenetic Inference in the Genomic Era
• Diplopoda — taxonomic overview
• Limestone Karsts of Southeast Asia: Imperiled Arks of Biodiversity
• MEGA7: Molecular Evolutionary Genetics Analysis Version 7.0 for Bigger Datasets
• Paleocene–Eocene and Plio–Pleistocene sea-level changes as “species pumps” in Southeast Asia: Evidence from Althepus spiders
• A revision of the minor species group in the millipede genus Nannaria Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae)

Discussions

• This unusual dragon millipede found in Thailand has alternately long and short legs, a rare trait known as ‘heteropody’. The researchers documented their find in Invertebrate Systematics: doi.org/10 [bsky, 0 points, 1 comments]

Related

• A taxonomic study of millipede genera, Orangutana Golovatch, 1996 and Gigantomorpha Jeekel, 1963 (Diplopoda, Polydesmida, Paradoxosomatidae), with description of four new species from Sabah, Borneo, East Malaysia
• The fifth element: reconnection of the disjunct distribution of the members of Siphonocryptida (Diplopoda) with the description of a new species from Nepal
• Millipede Taxonomy after 250 Years: Classification and Taxonomic Practices in a Mega-Diverse yet Understudied Arthropod Group
• The millipede genus Mandarinopus Verhoeff, 1933, is a junior synonym of Kronopolites Attems, 1914 (Polydesmida, Paradoxosomatidae), with a revision of the species based on integrated evidence
• Mountainous millipedes in Vietnam. IV. Three new Anoplodesmus Pocock, 1895 in northern Vietnam (Diplopoda, Polydesmida, Paradoxosomatidae), with notes on its phylogenetics