Tylopus parahilaroides, Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2014

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2014, Three new species of the millipede genus Tylopus Jeekel, 1968 from Thailand, with additional notes on the species described by Attems (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 435, pp. 63-91 : 68-71

Taxon classification Animalia Polydesmida Paradoxosomatidae

Tylopus parahilaroides sp. n. Figs 4, 5

Holotype.

♂ (CUMZ), Thailand, Loei Province, Phuluang District, Phuluang Wildlife Sanctuary, 1,486 m a.s.l., 17°16'44.9"N, 101°31'10.2"E, 20.07.2011, leg. Sira Noommeechai.

Paratype.

1 ♀ (CUMZ), same data, together with holotype.

Name.

To emphasize the close resemblance to Tylopus hilaroides Golovatch, 1984.

Diagnosis.

Very similar to Tylopus hilaroides , especially as regards its gonopod conformation, but differs in the presence of two rows of setae on metaterga 3-18 (an anterior transverse row of 2+2 setae and a posterior row of 4+4 insertion points versus solely an anterior transverse row of 2+2 setae), by the transverse sulcus visible starting already from metatergum 4 (versus metatergum 5), as well as in gonopod process z with two evident spines along distal margin (versus three spines) and process h being smaller (versus stouter).

Description.

Length 34 (♂) or 33 mm (♀), width of midbody pro- and metazonae 3.1 and 4.3 mm (♂) or 3.2 and 4.1 mm (♀), respectively.

Coloration of live animals dark castaneous brown (Fig. 4A); legs red-brown, venter and a few basal podomeres light brown to yellow-brown; coloration of alcohol material after a half year preservation faded to dark brown; antennae and epiproct light brown to pallid, venter and a few basal podomeres light brown to pallid (Fig. 4 B–H).

Clypeolabral region and vertex sparsely setose, epicranial suture distinct. Antennae moderately long (Fig. 4A), reaching behind body segment 3 (♂, ♀) when stretched dorsally. In width, head <segment 3 <4 <5 <collum <segment 2 <6-17 (♂) or head <segment 3 <4 <collum <segment 2 <5-17 (♀); thereafter body gently and gradually tapering. Collum with three transverse rows of setae: 4+4 anterior, 3+3 intermediate, and 4+4 posterior; a setigerous incision laterally in posterior 1/3; caudal corner of paraterga very narrowly rounded, not drawn behind rear tergal margin (Fig. 4B, C).

Tegument rather smooth and shining, prozonae finely shagreened, metaterga often rugose (Fig. 4 A–F); surface below paraterga finely microgranular (Fig. 4C, E, H). Postcollum metaterga with an anterior transverse row of 2+2 setae visible at least as insertion points, and a posterior row of 4+4 insertion points. Tergal setae long, strong, slender, about 1/3 of metatergal length. Axial line clearly visible both on pro- and metazonae. Paraterga strongly developed (Fig. 4 B–H), especially so in ♂, lying rather high (at 1/3 of midbody height), slightly upturned, but lying below dorsum; anterior edge rounded, caudal corner very narrowly rounded, starting from segment 13 extending increasingly beyond rear tergal margin, pointed, on segments 15-19 tips strongly curved mesad (Fig. 4F, H); lateral edge on poreless segments with two evident (anterior larger, posterior one smaller) setigerous incisions in anterior 1/3, but with only one strong (anterior) incision on pore-bearing segments (Fig. 4B, D, F); posterior edge oblique. Calluses on paraterga narrow, delimited by a sulcus only dorsally in segments 2-3, but both dorsally and ventrally in following segments. Paraterga 2 broad, posterior edge clearly oblique. Paraterga 2 and 3 broadly angular anteriorly, following segments with rounded anterior edges (Fig. 4B). Ozopores evident, lateral, lying in an ovoid groove at about 1/3 in front of posterior edge of metaterga. Transverse sulcus usually distinct (Fig. 4B, D, H), slightly incomplete on segments 4 and 19, complete on metaterga 5-18 (♂, ♀), narrow, wavy, rather deep, not reaching bases of paraterga, at most faintly ribbed at bottom. Stricture between pro- and metazonae broad and deep, beaded at bottom down to well below base of paraterga (Fig. 4B, D, H). Pleurosternal carinae complete crests with a sharp caudal tooth on segments 2-4, thereafter split into a sharp front and a sharp caudal tooth, the former gradually turning into a bulge, the latter tooth gradually reduced until segment 17 (♂, ♀). Epiproct (Fig. 4F, G) conical, flattened dorsoventrally, with two evident apical papillae; tip subtruncate; pre-apical papillae small, lying rather close to tip. Hypoproct roundly subtrapeziform, setiferous knobs at caudal edge small and well-separated (Fig. 4G).

Sterna densely setose, without modifications; a single, linguiform, sternal lobe between ♂ coxae 4 (Fig. 4I, J). Legs rather long and slender, midbody ones ca 1.2-1.3 (♂) or 1.1-1.4 times (♀) as long as body height; appressed setation ventrally on coxa, prefemur and femur, but tarsal brushes absent; ♂ prefemora distinctly bulged laterally (Fig. 5C), ♂ postfemora and tibiae on segments 7-17 with an evident adenostyle at midway on ventral side (Fig. 5C).

Gonopods (Fig. 5A, B) simple; coxa a little curved caudad, sparsely setose distoventrally. Prefemur densely setose, about 1/3 as long as femorite + “postfemoral” part. Femorite rather stout, expanded distad, slightly curved, showing a mesal groove; lobe l simple; process z with two evident spines along dorsal margin; process h short and slender, curved, with an acute tip; solenophore long and slender, typically coiled, tip subtruncate.