Gigaxytes, Srisonchai & Enghoff & Likhitrakarn & Panha, 2018

Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2018, A revision of dragon millipedes III: the new genus Gigaxytes gen. nov., with the description of three new species (Diplopoda, Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 463, pp. 1-43 : 9-11

Key to species of Gigaxytes gen. nov. (based mainly on males)

1. Male femora 5, 6, 7 without modification ( Fig. 10 E–F) ..................................................................... ................................................................. G. gigas ( Golovatch & Enghoff, 1994) gen. et comb. nov.

– Male femora 5, 6 or 5, 6, 7 with an apophysis (e.g., Fig. 15 E–G) ................................................... 2

2. Body brown. Only male femora 5 and 6 with apophyses ( Fig. 5 E–F); solenophore narrow laterally (e.g., Figs 7 C–D, 8C, E) ............................... G. fusca Srisonchai, Enghoff & Panha gen. et sp. nov.

– Body pinkish brown or brownish pink. Male femora 5, 6 and 7 with apophyses ( Figs 15 E–G, 20E–G); solenophore (sph) broad laterally (e.g., Figs 17C , 18C , 22C , 23C ) ........................................... 3

3. Paraterga short ( Fig. 16 A–B); collum usually with 3+3 cones/spines (intermediate row) ( Fig. 15A ); metaterga 2–8 usually with 4+4 cones/spines (anterior row), 3+3 cones/ spines (intermediate row) and 3+3 cones/spines (posterior row); metaterga 9–19 usually with 5+5 cones/spines (anterior row), 5+5 cones/spines (intermediate row) and 5+5 cones/spines (posterior row) ( Fig. 15 A–C) ......................................................... G. parvoterga Srisonchai, Enghoff & Panha gen. et sp. nov.

– Paraterga long ( Fig. 21 A–B); collum usually with 4+4 cones/spines (intermediate row) ( Fig. 20A ); metaterga 2–8 usually with 4+4 cones/spines (anterior row), 4+4 cones/ spines (intermediate row) and 4+4 cones/spines (posterior row); metaterga 9–12 usually with 5+5 cones/spines (anterior row), 5+5 cones/spines (intermediate row) and 5+5 cones/spines (posterior row); metaterga 13–19 usually with 6+6 cones/spines (anterior row), 6+6 cones/ spines (intermediate row) and 6+6 cones/spines (posterior row) ( Fig. 20 A–C) ................ G. suratensis Srisonchai, Enghoff & Panha gen. et sp. nov.

Figures

Fig. 10. Gigaxytes gigas (Golovatch & Enghoff, 1994) gen. et comb. nov., ³, specimen from Wat Tham Sue (Tiger Cave). A. Anterior body part. B. Body rings 8–10. C. Posteriormost body rings and telson. D. Head and antenna. E. Ƌ leg 5 (right). F. Ƌ leg 6 (right). G. Ƌ leg 13 (right). H. Midbody ring.

Fig. 15. Gigaxytes parvoterga Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype. A. Anterior body part. B. Body rings 8–10. C. Posteriormost body rings and telson. D. Head and antenna. E. Ƌ leg 5 (right). F. Ƌ leg 6 (right). G. Ƌ leg 7 (right). H. Ƌ leg 13 (right). I. Midbody ring.

Fig. 5. Gigaxytes fusca Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype. A. Anterior body part. B. Body rings 8–10. C. Posteriormost body rings and telson. D. Head and antenna. E. Ƌ leg 5 (right). F. Ƌ leg 6 (right). G. Ƌ leg 13 (right). H. Midbody ring.

Fig. 7. Gigaxytes fusca Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype – right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view (arrowead points to sharp tip of lamina medialis).

Fig. 17. Gigaxytes parvoterga Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype – right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view.

Fig. 18. Gigaxytes parvoterga Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype – right gonopod. A. Lateral view. B. Mesal view. C. Ventral view. D, F. Subdorsal view. E. Dorsal view.

Fig. 22. Gigaxytes suratensis Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype – right gonopod. A. Mesal view. B. Lateral view. C. Ventral view. D. Dorsal view.

Fig. 23. Gigaxytes suratensis Srisonchai, Enghoff & Panha gen. et sp. nov., ³, paratype – right gonopod. A. Lateral view. B. Mesal view. C. Ventral view. D, F. Subdorsal view. E. Dorsal view.

Fig. 16. Gigaxytes parvoterga Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype. A. Body rings 8–10. B. Paraterga of ring 10 (arrowhead points to ozopore). C–D. Last ring and telson. E. Hypoproct. F–G. Epiproct. H–J. Sternal lobe between coxae 4.

Fig. 21. Gigaxytes suratensis Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype. A. Body rings 8–10. B. Paraterga of ring 10 (arrowhead points to ozopore). C–D. Last ring and telson. E. Hypoproct. F–G. Epiproct. H–J. Sternal lobe between coxae 4.

Fig. 20. Gigaxytes suratensis Srisonchai, Enghoff & Panha gen. et sp. nov., ³ paratype. A. Anterior body part. B. Body rings 8–10. C. Posteriormost body rings and telson. D. Head and antenna. E. Ƌ leg 5 (right). F. Ƌ leg 6 (right). G. Ƌ leg 7 (right). H. Ƌ leg 13 (right). I. Midbody ring.