Orthomorpha subtuberculifera, Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2011

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2011, Revision of the Southeast Asian millipede genus Orthomorpha Bollman, 1893, with the proposal of a new genus (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 131, pp. 1-161 : 26-29

Orthomorpha subtuberculifera sp. n. Figs 2224

Holotype.

♂ (CUMZ), Thailand, Nakhon Ratchasima Prov., Wang Nam Khiao Distr., Sakaerat Enviromental Research Station, 14°50'N, 102°34'E, 15.07.2006, leg. S. Panha.

Paratypes.

1 ♂ (CUMZ), same data as holotype. 1 ♂, 3 ♀ (CUMZ), same locality, 10.01.2007, leg. N. Likhitrakarn.

Name.

To emphasize the strong similarity to Orthomorpha tuberculifera sp. n.

Diagnosis.

Comes closest to Orthomorpha tuberculifera sp. n., but differs in a strong anterolateral incision on paraterga (see also Key below).

Description.

Length 21-23 mm (♂), 23-24 mm (♀), width of midbody pro- and metazona 2.2-2.4 and 3.5-4.2 mm (♂), 2.1-3.7 and 3.4-4.3 mm (♀), respectively. Coloration of alcohol material after preservation uniformly blackish-brown (♀) or apparently faded to uniformly brown (♂), with paraterga, venter, distal part of epiproct and several basal podomeres more flavous, pallid to light yellow (Fig. 13B-J); antennomere 7 infuscate, brown to dark brown; legs sometimes infuscate distally, light brown.

All other characters as in Orthomorpha tuberculifera sp. n. (Fig. 13), except as follows.

Antennae longer (Fig. 22B), extending behind segment 3 (♂) or 2 (♀) dorsally.

Head in width <collum <segments 3-4 <2 <5-16 (♂, ♀); thereafter body gently and gradually tapering. Paraterga on collum slightly declivous, subtriangular, with a small, but evident indentation near midway and a small, caudally directed, sharp denticle at caudal corner, the latter not extending behind tergal margin (Fig. 22A & J). Paraterga very strongly developed (Fig. 22A-G & J-L), especially well so in ♂, mostly subhorizontal to faintly upturned, always lying below dorsum, set at about 1/4 midbody height; shoulders well-developed, mostly straight; caudal tips of paraterga pointed, always extending behind tergal margin. Calluses delimited by a sulcus both dorsally and ventrally, especially deeply so dorsally, rather broad, with three evident lateral incisions on callus 2 (front indentation being smallest) and two strong indentations on following segments (front one being extremely strong, middle one smallest) (Fig. 22A, C, F & J-L). Posterior edge of paraterga always strongly concave, more strongly so on segments 16-19 (Fig. 22F & L). Pleurosternal carinae large, roughly granulate crests with a distinct tooth both frontally and caudally, complete on segments 2-7 (♂, ♀), thereafter split into both front and caudal teeth, the former increasingly strongly reduced until segment 15 (♂) or 16 (♀), the latter tooth gradually reduced until segment 17 (♂) or 18 (♀), much more strongly developed in ♂ than in ♀ (Fig. 22B, D & E). Epiproct (Fig. 22E, F & L) with pre-apical papillae place closer to tip.

Sterna delicately and sparsely setose. Only small paramedian knobs in front of gonopod aperture. Legs moderately long and slender, almost not incrassate in ♂, midbody ones ca 1.2-1.3 (♂) or 0.9-1.1 times (♀) as long as body height, prefemora without modifications.

Gonopods (Figs 23 & 24) simple. Prefemoral part densely setose, less than 2 times shorter than femorite + “postfemoral” part. Femorite rather stout, slightly curved, nearly not enlarged distad, with a “postfemoral” part demarcated by an oblique lateral sulcus. Solenophore tip bifid, with terminal tooth bearing a minute denticle at base.

Remarks.

This new species has been found rather close to the localities of Orthomorpha tuberculifera sp. n., but northeast of the Sankamphaeng Mountain Range, Khao Yai National Park (Map 2).