Pimvichai, P.; Enghoff, H.; Panha, S.; Backeljau, T. (2016). A revision of the Thyropygus allevatus group. Part V: Nine new species of the extended opinatus subgroup, based on morphological and DNA sequence data (Diplopoda: Spirostreptida: Harpagophoridae). European Journal of Taxonomy. (199): 1-37.
The Thyropygus opinatus subgroup (Diplopoda: Harpagophoridae) of the T. allevatus group in Thailand is revised. Based on a phylogenetic analysis of mtDNA sequence data, it is merged with the T. bifurcus subgroup to form an extended T. opinatus subgroup. Nine new species are described: Thyropygus cimi sp. nov. and T. forceps sp. nov. from Nakhonsrithammarat Province, T. culter sp. nov., T. planispina sp. nov., T. undulatus sp. nov. and T. ursus sp. nov. from Krabi Province, T. mesocristatus sp. nov. from Songkhla Province, T. navychula sp. nov. from Phang-Nga Province and T. sutchariti sp. nov. from Phetchaburi Province.