Plusioglyphiulus erawan, Golovatch & Geoffroy & Mauriès & Vandenspiegel, 2011

Golovatch, Sergei I., Geoffroy, Jean-Jacques, Mauriès, Jean-Paul & Vandenspiegel, Didier, 2011, The millipede genus Plusioglyphiulus Silvestri, 1923 in Thailand (Diplopoda, Spirostreptida, Cambalopsidae) 2940, Zootaxa 2940 (1), pp. 1-63 : 24-27

Plusioglyphiulus erawan sp. n. Figs 20−23 .

Material examined: Holotype male ( MNHN GA 065 ), Thailand, Lamphun Prov., Pasang Distr., Cave Tham Erawan , 530 m a.s.l., 15 November 2009, leg. C. Sucharit and members of the Animal Systematics Research Unit . Paratypes: 29 males, 8 females, 27 juveniles ( MNHN GA 065 ) , 2 males, 2 females ( ZMUM) , 2 males, 2 females ( ZMUC) , 2 males, 1 female ( MZCU) , 2 males, 1 female ( NMNHS) , 1 male ( SEM) , same locality, together with holotype ; 8 males, 8 females, 18 juveniles ( MNHN GA 065 ) , 2 males, 1 female ( MZCU) , 2 males, 1 female ( ZMUM) , 1 male ( SEM) , same province and district, Cave Tham Tep Ni Mu , 470 m a.s.l., 25 November 2009, leg. C. Sucharit and members of the Animal Systematics Research Unit ; 21 males, 15 females, 3 juveniles ( MNHN GA 065 ) , 2 males, 1 female ( MZCU) , same province, Ban Hong Distr. , Cave Tham Luang Ha Wiang, 400 m a.s.l., 25 November 2009, leg. C. Sucharit and members of the Animal Systematics Research Unit .

Name: To emphasize Erawan both as the type locality and as a mythic 3-headed elephant, a noun in apposition and also to reflect the discovery of this species in three caves at once.

Diagnosis: Differs from congeners in the oligotrichous gnathochilarium, coupled with the particular carinotaxy patterns, and the special shapes and armature of both gonopod pairs (see also Key below).

Description: Length 20–41 mm, width 1.2–1.9 mm, collum and midbody segments being broadest and approximately equal. Coloration uniformly dark grey-brown to light yellow- to castaneous brown; antennae and collum often lighter, usually yellow-brown; metatergal crests and, especially, poriferous tubercles often infuscate.

Body with 47–67p+5–1a+T. Length of holotype about 40 mm, width 1.8 mm, with 64p+1a+T. Largest penultimate males about 16 mm long, 1.0 mm wide, with 45+5a+T.

All characters as in P. panhai sp. n. ( Figs 20E, F , 21A, C, E, G , 22A , 23A, E, F ), except as follows. Ocellaria large, blackish, ovoid in shape, with about 13–22 ocelli arranged in 4–6 longitudinal rows. Gnathochilarium ( Figs 21B , 23B ) rather oligotrichous, with a separate promentum (n=2).

Postcollum constriction very evident, due to especially enlarged collum and segment 2 ( Figs 20A, D ). Carinotaxy formula of collum: /(t)/t+/(t)/+1p/t+2p/t+3p/t+4a/t+pp/(t)/t+/ma/m ( Figs 20A, D ). Carinotaxy of metaterga 2– 4, 7/7+m/m+7/7; usual formula of following metaterga until about caudal third of body, 3/3+I/i+3/3/3+m/m/m, thereafter, 4/4+I/i+3/3/3+m/m/m ( Figs 20A–C , 21F ); all crests and tubercles, including poriferous cones, rather low. Midbody segments ovoid in cross-section, slightly compressed laterally ( Fig. 21F ).

Male legs 1 ( Fig. 23C ) with a usual strong central hook curved forward, appendages larger, sac-shaped, with a few setae mesally near base, 1-segmented. Male legs 2 strongly enlarged ( Fig. 23D ).

Anterior gonopods rather complex, with a paramedian pair of anterior coxosternal processes (cxp1), especially high, slender, nearly contiguous, digitiform, only at midway evidently expanded laterad and in distal quarter supplied with a rather sharp tooth on caudal face; caudal pair of coxosternal processes (cxp2) considerably shorter, slender and slightly curved; telopodites (te) finger-shaped, densely setose distally, slightly shorter than cxp2, attached to coxal region caudolaterally, probably capable of movement ( Figs 22B–E , 23G ). Posterior gonopods considerably shorter, rather simple, coxites well separated from sternum, fused only basally, sac-shaped, membranous, each surmounted on caudal face by an evident fovea with a rather short and simple uncus at base and with a very short flagellum on top; telopodites virtually missing ( Figs 22B–E , 23H ).

Figures

FIGURE 20. Plusioglyphiulus erawan sp. n., male paratype from Cave Erawan. A: anterior part of body, lateral view. B: midbody segments, lateral view. C: posterior part of body, lateral view. D: anterior part of body, dorsal view. E: midbody segments, dorsal view. F: posterior part of body, dorsal view. Scale bars: A–E, 0.5 mm; F, 0.2 mm.

FIGURE 21. Plusioglyphiulus erawan sp. n., male paratypes from Cave Erawan. A: anterior part of body, ventrolateral view. B: gnathochilarium, ventral view. C: midbody segments, ventral view. D: posterior part of body, ventral view. E: same, caudal view. F: cross-section of a midbody segment, caudal view; G: enlarged ozopore region, lateral view. Scale bars: A and F, 0.5 mm; B–E, 0.2 mm; G, 0.01 mm.

FIGURE 22. Plusioglyphiulus erawan sp. n., male paratypes from Cave Erawan. A: enlarged claw, lateral view. B: both gonopod pairs, front view. C: same, caudal view. D: same enlarged, caudoventral view. E: same, ventrolateral view. Scale bars: A, 0.02 mm; B−E, 0.1 mm.

FIGURE 23. Plusioglyphiulus erawan sp. n., male paratype from Cave Erawan. A: antenna, lateral view. B: gnathochilarium, ventral view. C: leg 1, front view. D: leg 2, front view. E: leg 3, front view. F: midbody leg, lateral view. G: anterior gonopods, caudal view. H: posterior gonopods, front view. te: telopodite; cxp1: anterior coxosternal process; cxp2: posterior coxosternal process. Scale bar: 0.2 mm.