Thyropygus opinatus (Karsch, 1881) Arw

Pimvichai, Piyatida, Enghoff, Henrik, Panha, Somsak & Backeljau, Thierry, 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, pp. 1-37 : 10-14

The Thyropygus opinatus subgroup (including the T. bifurcus subgroup of Pimvichai et al. 2009 b)

This is a subgroup of the T. allevatus group, characterized by an additional projection on the anterior coxal fold (amp). Included species:

T. bearti Pimvichai et al., 2009a

T. bifurcus ( Demange, 1986)

T. bispinispatula Pimvichai et al., 2009a

T. bispinus Pimvichai et al., 2009a

T. brachyacanthus Pimvichai et al., 2009a

T. casjeekeli Pimvichai et al., 2009b

T. chelatus Pimvichai et al., 2009a

T. cristagalli Pimvichai et al., 2009a

T. demangei Pimvichai et al., 2009b

T. enghoffi ( Demange, 1989)

T. erectus Pimvichai et al., 2009a

T. floweri ( Demange, 1961)

T. implicatus ( Demange, 1961)

T. inflexus ( Demange, 1989)

T. loxia Pimvichai et al., 2009a

T. opinatus ( Karsch, 1881)

T. quadricuspis Pimvichai et al., 2009b

T. richardhoffmani Pimvichai et al., 2009b

T. cimi sp. nov.

T. culter sp. nov.

T. forceps sp. nov.

T. mesocristatus sp. nov.

T. navychula sp. nov.

T. planispina sp. nov.

T. sutchariti sp. nov.

T. undulatus sp. nov.

T. ursus sp. nov.

In addition to the diagnostic character combination given by Pimvichai et al. (2009a, b), all species in the opinatus subgroup share common characters of head, antennae, mandibles, gnathochilarium, collum, epiproct, paraprocts, hypoproct and first pair of male legs. We therefore give a general description of males of the opinatus subgroup, so that subsequent species descriptions (which are mainly based on males) can be kept brief.

General description of males of the T. opinatus subgroup

Head smooth, 5–8 supralabral setae, eyes moderate in size, ocelli in 7–8 horizontal rows consisting of 11–14, 10–13, 8–11, 7–9, 5–8, 3–6, 1–4 and 1–3 ocelli, total: 46–68.

Gnathochilarium: mentum smooth, at most with a few small setae distally and a large, horseshoe-shaped ridge opening distally. Stipites densely covered with spine-like setae, except for an irregular oblique band from c. middle of lateral margin to border of lamella lingualis; long setae present on the distolateral part; males (not females) distally with a small sclerotised ‘island’ with 1–3 spine-like setae in middle of an ovoid, poorly sclerotized, hairless area. Lamellae linguales with three long, apical setae and a number of short, basal, spine-like setae.

Sterna smooth, stigmatal grooves distinct, long. Legs relatively long; tip of postfemora, tibiae and tarsi visible from above when legs are extended laterad; coxae of anterior and posterior pair markedly dissimilar, posterior coxae humped; coxae with 2–8 setae, prefemora with 3–6 setae, femora with 2–5 setae in a median row and 2 larger, subapical setae; tarsi typically with 6–8 irregularly placed ventral setae and 1–2 large dorsal, apical spurs. Postfemora and tibiae without setae.

Ventral pads on postfemora and tibiae on all legs, except first three pairs.

Gonopods: sternum (st) triangular. Anterior coxal fold (ac) basally slender, becoming broader towards tip, lateral margins diverging; distally with two processes: a lateral process (alp) and a usually smaller mesal process (amp); the shape of these processes is species-specific. Posterior coxal (pc) fold much lower than anterior coxal fold, basally with moderately high lateral paracoxites (px), distally variously modified but always with a smooth area over which the telopodite shaft can slide. Telopodite with a single or double, well-developed femoral spine (fe) and a long, slender, curved tibial spine (ti). Many species with a characteristic spatulate lobe (sl) originating under the base of the tibial spine; lobe sometimes distally rounded, spoon-like, sometimes ending in a large, stout spine. Other species instead with a small and slightly folded lateral lamella (ll). Apical palette (pa) simple, forming a broad gutter, sometimes with a longitudinal crest in the concavity; apically with a row of 7–13 brownish blepharochaetae (bp).

Key to species of the T. opinatus subgroup (partly extracted and adapted from Pimvichai et al. 2009a, b)

1. Apical part of telopodite with spatulate lobe (sl)............................................................................2

− Apical part of telopodite with lateral lamella (ll)...........................................................................20

2. Spatulate lobe (sl) distally drawn out into one (rarely two) sharp dark brown spine(s)............3

− Spatulate lobe (sl) distally expanded and/or rounded, spoon-like, without a spine....................9

3. Spatulate lobe (sl) terminating in two sharp brown spines, the outer spine slightly smaller and shorter than the inner one; lateral process of anterior coxal fold (alp) slender, slightly curving mesad; mesal process of anterior coxal fold (amp) almost as long as alp, flattened ............................ .............................................................................................. T. bispinispatula Pimvichai et al., 2009a

− Spatulate lobe (sl) terminating in a single sharp dark brown spine.............................................4

4. Telopodite without a lobe distal to femoral spine (fe); lateral process of anterior coxal fold (alp) long, slender, regularly curved, tip close to tip of opposite alp, the two together forming a circle; mesal process of anterior coxal fold (amp) straight, shorter than alp; fe directed distad, pointed ...................................................................................................... T. erectus Pimvichai et al., 2009a

− Telopodite distally to fe with a large, round lobe (lo), projecting distolaterally.....................5

5. Lateral process of anterior coxal fold (alp) very slender, regularly curved...........................6

− Lateral process of anterior coxal fold (alp) different, broader and/or with several apical denticles...8

6. Mesal margin of lateral process of anterior coxal fold (alp) with fine serrations ( Fig. 6A ); mesal process of anterior coxal fold (amp) almost as long as alp, broadly expanded, apically sharp, straight distad, mesal margin forming a strong longitudinal crest (lc) in posterior view ( Fig. 6B ) ........................................................................................................................... T. navychula sp. nov.

− Mesal margin of lateral process of anterior coxal fold (alp) without serrations, tip of lateral process close to tip of the opposite side, the two together forming a circle..............................7

7. Mesal process of posterior coxal fold (pmp) strongly developed along anterior-posterior axis ..... ................................................................................................................. T. floweri ( Demange, 1961)

− Mesal process of posterior coxal fold (pmp) slender, directed distolaterad ( Fig. 4C ) .................... ................................................................................................................................ T. forceps sp. nov.

8. Lateral process of anterior coxal fold (alp) broad, apically gradually narrowed; mesal process of anterior coxal fold (amp) almost as long as alp, slender, straight, terminally slightly curved, pointed ....................................................................................................... T. opinatus ( Karsch, 1881)

− Lateral process of anterior coxal fold (alp) apically bent abruptly mesad, tip with serrate margins; mesal process of anterior coxal fold (amp) much shorter than alp, directed meso-distad, simple, pointed; mesal process of posterior coxal fold (pmp) strongly developed along anteriorposterior axis ................................................................................... T. implicatus ( Demange, 1961)

9. Telopodite with a single femoral spine..........................................................................................10

− Telopodite with a double femoral spine..........................................................................................17

10. Lateral process of anterior coxal fold (alp) apically abruptly truncate .......................................... ......................................................................................................... T. bearti Pimvichai et al., 2009a

− Lateral process of anterior coxal fold (alp) apically pointed.........................................................11

11. Mesal process of anterior coxal fold (amp) very small; telopodite distally to fe with a small round lobe (lo) projecting distolaterally ......................................... T. loxia Pimvichai et al., 2009a

− Mesal process of anterior coxal fold (amp) relatively long....................................................12

12. Mesal process of anterior coxal fold (amp) shorter than lateral process (alp)...........................13

− Mesal process of anterior coxal fold (amp) as long as lateral process (alp)..............................14

13. Mesal process of anterior coxal fold (amp) directed obliquely disto-mesad, slender, straight .......... ...................................................................................................... T. chelatus Pimvichai et al., 2009a

− Mesal process of anterior coxal fold (amp) directed distad, thicker, slightly sigmoid ....................... ........................................................................................ T. brachyacanthus Pimvichai et al., 2009a

14. Mesal process of anterior coxal fold (amp) directed obliquely disto-mesad, tip overlapping tip of opposite amp ( Fig. 8A ); lateral process of posterior coxal fold (plp) a massive, broad lobe, projecting laterad ( Fig. 8B ) ................................................................ T. sutchariti sp. nov.

− Mesal process of anterior coxal fold (amp) directed distad.........................................................15

15. Lateral process of anterior coxal fold (alp) apically without a crest; telopodite distally with a rounded lobe (lo); margins of spatulate lobe (sl) terminally meeting in a distinct angle ............... .................................................................................................... T. bispinus Pimvichai et al., 2009a

− Lateral process of anterior coxal fold (alp) apically with a crest.............................................16

16. Mesal process of anterior coxal fold (amp) apically irregularly tuberculate; telopodite distally without a rounded lobe (lo) ..................................................................... T. inflexus ( Demange, 1989)

− Mesal process of anterior coxal fold (amp) slender, straight, its tip pointed, its mesal margin forming a strong longitudinal crest (lc) in posterior view ( Fig. 5B ) .......... T. mesocristatus sp. nov.

17. Anterior coxal fold (ac) with an additional spine-like process (aip) between lateral process of anterior coxal fold (alp) and mesal process of anterior coxal fold (amp); alp broad, mesal margin concave, tip with serrate margins, cockscomb-like; amp much shorter than alp, directed meso-distad, simple, pointed; both femoral spines (fe) slender, long ............ T. cristagalli Pimvichai et al., 2009a

− Anterior coxal fold (ac) without an additional spine-like process (aip) between alp and amp ...18

18. Lateral process of anterior coxal fold (alp) apically without a crest, flattened, slightly curved, its laterodistal margin coarsely dentate, terminating in a short, sharp, pointed spine ( Fig. 3A ); mesal process (amp) much shorter than alp, directed distad, tip curving mesad, pointed; both femoral spines (fe 1, fe 2) long, curving backward; tibial spine (ti) long, not curving in horizontal plane ( Fig. 3C ) ......... ................................................................................................................................... T. culter sp. nov.

− Lateral process of anterior coxal fold (alp) apically with a crest extending caudad...............19

19. Lateral process of anterior coxal fold (alp) flattened, curving mesad, laterodistal margin coarsely dentate, terminating in a short spine, tip curving against the tip of opposite side ( Fig. 9A ); mesal process of anterior coxal fold (amp) much shorter than alp, slender, curving mesad; both femoral spines (fe 1, fe 2) broad, long; tibial spine (ti) long, curving in horizontal plane, not ending in a sharp spine ( Fig. 9D ) .................................................................... T. undulatus sp. nov.

− Lateral process (alp) regularly curved, terminating in a sharp, slightly upward-pointing spine ( Fig. 7A ); mesal process (amp) slightly shorter than alp, flattend, straight, directed distad; tibial spine (ti) flattend, short, curving mesad ( Fig. 7D ) ........................................... T. planispina sp. nov.

20. Telopodite with a single femoral spine.......................................................................................21

− Telopodite with a double femoral spine.......................................................................................23

21. Lateral process of anterior coxal fold (alp) without an apical crest; mesal process of anterior coxal fold (amp) shorter than and as broad as alp, directed distad; femoral spine (fe) very long and slender .............................................................. T. casjeekeli Pimvichai et al., 2009b

− Lateral process of anterior coxal fold (alp) with a sharp crest on the posterior surface near the tip...22

22. Lateral process of anterior coxal fold (alp) flattened, slightly curved, inflexed; femoral spine (fe) very long, slender, with an additional lamella at base ... T. quadricuspis Pimvichai et al., 2009b

− Lateral process of anterior coxal fold (alp) regularly curved, basally broad, gradually tapering towards end and ending in sharp point ( Fig. 2A ); femoral spine (fe) very long, slender, without an additional lamella at base ( Fig. 2D ) ............................................................................ T. cimi sp. nov.

23. Lateral process of anterior coxal fold (alp) broader..................................................................24

− Lateral process of anterior coxal fold (alp) slender, regularly curved, sickle-shaped............25

24. Lateral process of anterior coxal fold (alp) terminating in a very short external spine and a very long internal one; mesal process of anterior coxal fold (amp) as long as alp; first femoral spine (fe 1) very short, pointed; second femoral spine (fe 2) very long, as long as tibial spine (ti); an additional lamella at both sides of base of fe 2 ........................ ... T. richardhoffmani Pimvichai et al., 2009b

− Lateral process of anterior coxal fold (alp) flattened, apically curved laterad as a short spine, lateral margin of alp slightly folded; mesal process of anterior coxal fold (amp) shorter than alp, slender, straight, directed distad, pointed ( Fig. 10A ); the first femoral spine (fe 1) very short, directed upward, situated above the second femoral spine (fe 2); fe 2 very long, slender, curved downward ( Fig. 10C ) .................................................................................. T. ursus sp. nov.

25. Mesal margin of lateral process of anterior coxal fold (alp) simple, without a caudad spine or crest; mesal process of anterior coxal fold (amp) much shorter than alp, curved, pointed ............................. ................................................................................................................ T. enghoffi ( Demange, 1989)

− Mesal margin of lateral process of anterior coxal fold (alp) caudad with a small spine or crest......26

26. Mesal margin of lateral process of anterior coxal fold (alp) with a small caudad crest; mesal process of anterior coxal fold (amp) slightly shorter than alp, slightly sigmoid, pointed ............... ............................................................................................................ ... T. bifurcus ( Demange, 1986)

− Mesal margin of lateral process of anterior coxal fold (alp) with a short curved caudad spine; mesal process of anterior coxal fold (amp) as long as alp, straight ... T. demangei Pimvichai et al., 2009b

Figures

Fig. 6. Thyropygus navychula sp. nov., from Surin Islands, holotype (CUMZ-D00095), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Left telopodite, posterior-mesal view. D. Left telopodite, anterior-lateral view.

Fig. 4. Thyropygus forceps sp. nov., gonopods. –A, C–E. Holotype (CUMZ-D00092), ♂, from Namwang Srithammasokrach.A. Anterior view, left telopodite removed. C. Posterior view, left telopodite removed. D. Left telopodite, posterior-mesal view. E. Left telopodite, anterior-lateral view. – B. Specimen from Tham Pha Deang temple (CUMZ-D00093), ♂. Anterior view, left telopodite removed.

Fig. 8. Thyropygus sutchariti sp. nov., from Kaeng Krachan, holotype (CUMZ-D00090), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Left telopodite, posterior-mesal view. D. Left telopodite, anterior-lateral view.

Fig. 5. Thyropygus mesocristatus sp. nov., from Srikasorn, holotype (CUMZ-D00094), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Lateral view. D. Left telopodite, posterior-mesal view. E. Left telopodite, anterior-lateral view.

Fig. 3. Thyropygus culter sp. nov., from Rorn waterfall, holotype (CUMZ-D00091), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Left telopodite, posterior-mesal view. D. Left telopodite, anterior-lateral view.

Fig. 9. Thyropygus undulatus sp. nov., from Khao Phanom Bencha, holotype (CUMZ-D00087), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Lateral view. D. Left telopodite, posterior-mesal view. E. Left telopodite, anterior-lateral view.

Fig. 7. Thyropygus planispina sp. nov., from Tham Sua temple, holotype (CUMZ-D00088), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Lateral view. D. Left telopodite, posterior-mesal view. E. Left telopodite, anterior-lateral view.

Fig. 2. Thyropygus cimi sp. nov., from Namwang Srithammasokrach, holotype (CUMZ-D00086), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Lateral view. D. Left telopodite, posterior-mesal view. E. Left telopodite, anterior-lateral view.

Fig. 10. Thyropygus ursus sp. nov., from Lanta Islands, holotype (NMHW-Inv.7855), ♂, gonopods. A. Anterior view, left telopodite removed. B. Posterior view, left telopodite removed. C. Left telopodite, posterior-mesal view. D. Left telopodite, anterior-lateral view.