Wednesday, July 8, 2026

[Diplopoda • 2026] Enghoffosoma chiangmaiense, ER. minutum, E. chanabunae • Integrative Taxonomy of the Millipede Genus Enghoffosoma Golovatch, 1993 (Polydesmida: Paradoxosomatidae) in Thailand and Myanmar, with Descriptions of Three New Species


Enghoffosoma chiangmaiense Srisonchai & Likhitrakarn; 
E. minutum Srisonchai & Likhitrakarn; 
 E. chanabunae Srisonchai & Likhitrakarn, 
 
 in Srisonchai, Benchapong, Golovatch, Sutcharit, Panha et Likhitrakarn, 2026. 

Abstract
Although comprehensive studies on the Southeast Asian flat-backed millipede genus Enghoffosoma Golovatch, 1993 in Thailand have begun quite recently, in 2014, continuous field surveys have since revealed a steadily increasing species diversity. Based on extensive new material collected from Thailand and Myanmar, three new species are described using an integrative taxonomic approach that combines morphological characters and mitochondrial COI DNA barcoding: Enghoffosoma chiangmaiense Srisonchai & Likhitrakarn sp. n. from northern Thailand, Enghoffosoma minutum Srisonchai & Likhitrakarn sp. n. from northeastern Thailand, and Enghoffosoma chanabunae Srisonchai & Likhitrakarn sp. n. from the Tanintharyi Region, southern Myanmar. COI sequence comparisons, available for E. chanabunae Srisonchai & Likhitrakarn sp. n. and E. chiangmaiense Srisonchai & Likhitrakarn sp. n., reveal significant interspecific genetic divergences (K2P distances) from their congeners, ranging from 13.53–16.75% and 13.53–18.14%, respectively. While DNA data were unavailable for E. minutum Srisonchai & Likhitrakarn sp. n., its distinctive morphological characters, particularly the gonopod structure, clearly support its status as a new species. To provide a clear morphological baseline for comparison, the type species, Enghoffosoma spinipleurum (Carl, 1941), from Myanmar, originally described as Sundanina spinipleura Carl, 1941, is redescribed and illustrated in detail based on the lectotype. With these additions, the genus Enghoffosoma now comprises 21 valid species, confirming its status as a highly diverse and widespread diplopod lineage in the Indochinese region. An updated identification key to all known species and a distribution map are provided.


Enghoffosoma chiangmaiense Srisonchai & Likhitrakarn sp. n. 


 Enghoffosoma minutum Srisonchai & Likhitrakarn sp. n. 



 Enghoffosoma chanabunae Srisonchai & Likhitrakarn sp. n. 



Ruttapon Srisonchai, Theemaporn Benchapong, Sergei I. Golovatch, Chirasak Sutcharit, Somsak Panha, Natdanai Likhitrakarn. 2026. Integrative Taxonomy of the Millipede Genus Enghoffosoma Golovatch, 1993 (Diplopoda, Polydesmida, Paradoxosomatidae) in Thailand and Myanmar, with Descriptions of Three New Species. Ecologica Montenegrina. 99; 40-71. DOI: doi.org/10.37828/em.2026.99.4 [2026-06-24]