Thyropygus bifurcus ( Demange, 1986 )

Pimvichai, Piyatida, Enghoff, Henrik & Panha, Somsak, 2009, A revision of the Thyropygus allevatus group. Part 2: the T. bifurcus subgroup (Diplopoda, Spirostreptida, Harpagophoridae), Zootaxa 2165, pp. 1-15 : 4-5

Thyropygus bifurcus ( Demange, 1986)

( Figs. 1 A–E)

Thyropisthus bifurcus Demange, 1986: 852

[ Thyropisthus bifurcatus Demange, 1986: 853 , lapsus calami] Thyropygus bifurcus: Enghoff 2005: 93

Cornugonus bifurcus: Jeekel 2006: 19

Material: HOLOTYPE male THAILAND, Nakhonsrithammarat Province, Khao Luang, 8° 34ˏ 39˝ N, 99° 42ˏ 55˝ E, B. Degerbøl leg., ( ZMUC). – 1 male paratype, same data as holotype ( ZMUC).

Diagnosis: A species of the bifurcus subgroup. Lateral margin of lateral process of anterior coxal fold (alp) with a small crest. Similar in this respect to T. demangei and T. quadricuspis . Differs from T. demangei by having the first femoral spine (fe 1) almost as long as the second femoral spine (fe 2). Differs from T. quadricuspis by having a double femoral spine (fe). Differs from all other species of the T. bifurcus subgroup by having the lateral margin of alp folded caudad along the whole length.

Description: Adult males with 61–63 podous rings, no apodous rings. Length ca. 10 cm (broken), width ca. 8.0 mm. Color in life unknown; preserved holotype with head, antennae, legs, prozona, epiproct, paraprocts, and hypoproct brown; metazona and margins of paraprocts dark brown.

Gonopods ( Figs. 1 A–E): Anterior coxal fold (ac) ( Fig. 1 A): lateral process (alp) regularly curved, in anterior view sickle-shaped, lateral margins folded caudad along entire length, with a small crest ( Fig. 1 C, arrow), ca. 1/3 from tip; mesal process (amp) slightly shorter than lateral process, directed distad, slightly sigmoid, pointed. Posterior coxal fold (pc) ( Fig. 1 B) basally with moderately high lateral paracoxites (px), distally truncate, forming shelf (sh) for accommodation of telopodite; mesal process (pmp) slender, directed distolaterad. Telopodite ( Figs. 1 D–E) leaving coxite over shelf of posterior coxal fold; double femoral spine (fe), the first fe (fe 1) slender, inflexed, in situ resting against posterior surface of alp, the second fe (fe 2) situated under fe 1, slender, curved rearwards; tibial spine (ti) long, slender, curving in horizontal plane; apical part: lamellar lobe (ll) small, slightly twisted; palette (pa) simple, with a longitudinal rounded crest (cr) near tip, distally with about eight brownish blepharochaetae (bp).

Distribution ( Fig. 8 ): Known only from the type locality.

Figures

FIGURE 1. Thyropygus bifurcus, holotype, gonopods. A: anterior view, right telopodite removed. B: posterior view, right telopodite removed. C: lateral view. D: right telopodite, posterior-mesal view. E: right telopodite, anterior-lateral view.

FIGURE 8. Map of peninsular Thailand, showing the known distribution of the species of the T. bifurcus subgroup.