Siamaxytes Srisonchai and Panha, 2024

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai, Jeratthitikul, Ekgachai, Jirapatrasilp, Parin, Panha, Somsak & Sutcharit, Chirasak, 2024, Molecular phylogeny of dragon millipedes (Diplopoda: Polydesmida: Paradoxosomatidae) from mainland SouthEast Asia, with description of a new genus and species, Zoological Journal of the Linnean Society 202 (1), pp. 1-33 : 21-23

Genus Siamaxytes Srisonchai and Panha gen. nov.

Zoobank registration: urn:lsid:zoobank.org:act:39181782-C1FC-49B0-97FE-46B52D499E4D .

Type species

Siamaxytes bifurca sp. nov.

Etymology

The name of the new genus is a combination of Siam,the former name of Thailand, and -xytes, an ending used in the names of other dragon millipede genera, i.e. Burmaxytes , Desmoxytes , Gigaxytes , Nagaxytes , and Spinaxytes (and also its synonym Pteroxytes ). Feminine.

Diagnosis

A genus of dragon millipede characterized by the combination of these characters: (i) body sculpture with tiny microganulation— not smooth as in Desmoxytes and Spinaxytes , (ii) metaterga with two transverse rows of small cones/spines—not three transverse rows as in Gigaxytes and some Hylomus species, (iii) the presence of caudalateral spine behind the base of paraterga—not absent as in Gigaxytes , (iv) ozopores present only on rings 5 and 7—not present body rings 5, 7, 9, 10, 12, 13, and 15–19 as in Burmaxytes , Desmoxytes , Gigaxytes , Hylomus , Nagaxytes , and Spinaxytes , (v) only male femora 6 and 7 modified—not unmodified as in Nagaxytes , (vi) lamina lateralis distinctly demarcated from lamina medialis—not indistinctly demarcated as in Burmaxytes , Gigaxytes , and Hylomus , and (vii) lamina medialis branched into two processes—not unbranched as in Burmaxytes , Desmoxytes , Gigaxytes , Hylomus , Nagaxytes , and Spinaxytes (see also Table 2 ).

Remarks

The new genus exhibits subspiniform paraterga and a very long lamina medialis (lm) of the gonopod. These aspects are similar to the genus Nagaxytes , but this new genus differs from Nagaxytes by having longer paraterga; lamina medialis of gonopod bifurcated into two processes (vs one lobe/process), and the presence of defensive glands (ozopores) only on rings 5 and 7. The genus Gigaxytes also has subspiniform paraterga, but the relatively short lamina medialis and sheathed solenomere in combination with the presence of caudolateral spines on posterior part of metaterga make them different from the new genus.