Tokyosoma bifurcatum, Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hseuh-Wen, 2010

Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hseuh-Wen, 2010, The millipede family Diplomaragnidae in Taiwan, with descriptions of nine new species (Diplopoda, Chordeumatida), Zootaxa 2615, pp. 23-46 : 27-29

Tokyosoma bifurcatum sp. nov.

Figs 9–11 .

Material examined: Holotype: 1 male ( NMNS –6345–006), Taiwan, Taichung County, Heping Township, Taroko National Park, Tuleng, NW foot of Mt Diojiatun, 24°23.229’ N, 121°21.536’ E, 2043 m, secondary broad-leaved forest, 14 October 2009, leg. L. Dányi & E. Lazányi.

Diagnosis: Differs from congeners mainly by the shape of the posterior gonopod lateral coxal branch bifurcated distally into long and slender branches, by the form of the posterior gonopod colpocoxite with a long, slender, flat outgrowth distally, as well as in a rounded cup-shaped coxal process of male leg 10.

Description: Male. Length about 12 mm, width with paraterga about 1.0 mm. Coloration in alcohol marbled pale brown with a pattern of transverse brown bands and pale spots on dorsum. Legs with marbled, light brown, distal parts. Venter, proximal part of legs and lower portions of pleura pale. Head brown with marbled brown spots. Ocellaria black. Antennae brown with pale brown proximal parts.

Body with 29 segments. Head covered with dense, relatively long setae. Each eye patch composed of at least 20 ocelli. Collum semi-circular. Body width gradually increasing until somite 7, body parallel-sided on somites 8–15(16), thereafter gradually tapering. Beginning from somite 5, paraterga normally developed, growing increasingly less distinct towards hind part of body, strongly reduced on somites 25–27 (as well as on somite 2), absent from somites 28–31. Paraterga of somites 3 and 4 small. Metazonital macrochaetae in a transverse row on somites 29–31, like an elongate (to different degrees) triangle on preceding somites. Nearly all macrochaetae broken off, remaining ones in anterior part of body long, pointed apically, but in posterior part of body short (baton-shaped) and blunt. Metazonites with two knobs placed near axial suture on each side.

Leg pairs 3–7 somewhat enlarged. Leg pairs 6 and 7 with a group of funnel-shaped tarsal papillae apically near claw. Claw of leg pair 7 at base with a long setoid filament ventrally, but without additional dorsal claw. Claw of leg pair 6 at base with a long setoid filament ventrally and a small, dorsal, additional claw. Postgonopodal legs (including leg pairs 10 and 11) without tarsal papillae. Claw of legs 10 and 11 at base with one small additional claw dorsally and a long setoid filament ventrally. Claw of midbody and hindmost legs at base with one small additional claw dorsally and a long setoid filament ventrally.

Legs 10 and 11 with coxal glands. Coxa 10 with a caudoventral, rounded, cup-shaped process curved anteriad and papillate apically ( Fig. 9 ). Surface of coxa 10 covered with papillae mainly caudally. Trochanter 10 with a tiny ventral outgrowth setose apically. Coxa 11 covered with low papillae mainly caudally, without processes. Trochanter 11 with a caudal finger-shaped process papillate mesally and rounded apically.

Anterior gonopod telopodite 1-segmented, flagelliform, beset with cuticular spinules, its distal part positioned inside sheaths with very strongly elevated and tightly closed edges (e) ( Fig. 10 ). These sheath edges like high plates in lateral view. Telopodite base and distal part of coxosternum tightly attached to adjacent mesal portion of posterior gonopod. Posterior gonopod colpocoxites fused sub-basally. Colpocoxites distally with slender flat processes (c) somewhat curved posteriad, and laterally with thin rounded blades (b). Mesal sheath processes of posterior gonopod colpocoxites fused medially into a single cup-shaped structure (ms) carrying pointed spinules and a middle spine. Lateral sheath processes of colpocoxites (lp) cup-shaped, caudally covered with pointed spinules of different length.

Posterior gonopod angiocoxite with a globule, but without process in posterior view. Posterior gonopod coxal part with a long lateral branch (lb) bifurcated distally into long, slender and bifid apically branches. Basal part of lb fused with both colpocoxite and anterior angiocoxite.

Angiocoxite depressed centrally in anterior view ( Fig. 11 ), supplied with a long process (ap); distal portion of this process penetrating colpocoxite and visible outside in anterolateral view. Posterior gonopod telopodite 2-segmented; trochanteroprefemur hollow for accommodation of lateral branch (lb) mesocaudally; femur like a subconical knob (part of femur visible through wall of trochanteroprefemur of posterior gonopod telopodite).

Female unknown.

Name: The specific epithet refers to the posterior gonopod lateral coxal branch being bifurcated distally.

Figures

FIGURES 9 – 11. Tokyosoma bifurcatum sp. nov., male holotype. 9, coxa and trochanter 10, front view; 10, gonopods, caudal view; 11, gonopods, front view; e, edge of posterior gonopod colpocoxite sheath; c, distal processes of posterior gonopod colpocoxites; b, posterior gonopod colpocoxite lateral blade; ms, mesal sheath processes of posterior gonopod colpocoxites; lp, lateral sheath process of posterior gonopod colpocoxite; lb, posterior gonopod lateral coxal branch; ap, anterior process of posterior gonopod angiocoxite. Scale in mm.