Tylopus sutchariti, Likhitrakarn & Golovatch & Srisonchai & Panha, 2021

Likhitrakarn, Natdanai, Golovatch, Sergei I., Srisonchai, Ruttapon & Panha, Somsak, 2021, Two new species of the millipede genus Tylopus Jeekel, 1968 from Shan State, Myanmar (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 1040, pp. 167-185 : 167

publication ID	https://dx.doi.org/10.3897/zookeys.1040.66209
publication LSID	lsid:zoobank.org:pub:910903D2-476A-439F-AC73-292D5B9A18C1
persistent identifier	https://treatment.plazi.org/id/5385A3A0-C129-41F3-9A8C-C3910EF9178C
taxon LSID	lsid:zoobank.org:act:5385A3A0-C129-41F3-9A8C-C3910EF9178C
treatment provided by	ZooKeys by Pensoft
scientific name	Tylopus sutchariti
status	sp. nov.

Treatment

Tylopus sutchariti View in CoL sp. nov. Figs 1B View Figure 1 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7

Material examined.

Holotype: Myanmar - Shan State • ♂; Taunggyi District, near Montawa Cave ; elev. 1204 m; 20°45'15.9"N, 97°01'03.4"E; 21 Sep. 2016; R. Srisonchai leg.; CUMZ GoogleMaps . Paratype: Myanmar - Shan State • 1 ♀; same collection data as holotype; CUMZ GoogleMaps .

Diagnosis.

This new species comes to a dead end in couplet 5 in the latest key to Tylopus species ( Likhitrakarn et al. 2016), but it seems to be particularly similar to the later described and grossly sympatric T. brehieri Golovatch, VandenSpiegel & Semenyuk, 2016, especially in its gonopod conformation. Both species compared come from Shan State, Myanmar ( Golovatch et al. 2016), but T. sutchariti sp. nov. differs in the presence of a small and triangular gonopod process h (vs. absent), and the large and subtrapeziform apicolateral lobe (l) with a smooth apical margin (Figs 6B, D View Figure 6 , 7B View Figure 7 ) (vs. a subtriangular l with an apically rugose and denticulate margin), as well as the pleurosternal carinae being complete crests with a caudal tooth clearly visible until segments 16 (♂) or 13 (♀), thereafter missing (Fig. 5B, D, E View Figure 5 ) (vs. visible until segment 10), while the sternal lobe between ♂ coxae 4 is deeply notched (Fig. 5H, I View Figure 5 ) (vs. prominent and subquadrate).

Description.

Length 24.1 (♂) or 22.5 mm (♀), width of midbody pro- and metazona 1.8 and 2.7 mm (♂) or 2.2 and 2.6 mm (♀), respectively.

Colouration of live animals dark brown (Fig. 1B View Figure 1 ); venter and legs brown; colouration of alcohol material after two years of preservation blackish, calluses of paraterga yellowish brown, head and antennae dark brown, venter and legs light yellowish, increasingly darker brown distally (Fig. 5 View Figure 5 ).

Clypeolabral region and vertex sparsely setose, epicranial suture distinct. Antennae short (Figs 1B View Figure 1 , 5B View Figure 5 ), reaching body segment 3 (♂) or surpassing body segment 2 (♀) when stretched dorsally. In width, head <segment 3 <4 <5 <collum <segment 2 <6-17 (♂, ♀); thereafter body gently and gradually tapering. Collum with three transverse rows of strong setae: 3+3 anterior, 1+1 intermediate, and 3+3 posterior; a small lateral incision near midway; caudal corner of paraterga rounded, slightly declined ventrad, not surpassing rear tergal margin (Fig. 5B View Figure 5 ).

Tegument rather smooth and shining, prozonae very finely shagreened, metaterga smooth and finely rugulose; surface below paraterga finely microgranulate (Fig. 5A-F View Figure 5 ). Postcollum metaterga with two transverse rows of rather long setae: 2+2 in anterior and 2(3)+2(3) in posterior row, the latter often abraded, but then readily traceable as insertion points. Tergal setae long, strong, slender, about 1/3 metatergal length. Axial line visible only on metazonae.

Paraterga strongly developed (Fig. 5A-F View Figure 5 ), especially well so in ♂, set high, at upper 1/3 of midbody height, slightly upturned, but remaining below dorsum; anterior edge well-developed, mostly regularly rounded and narrowly bordered, continuous with callus; caudal corner narrowly rounded to fully pointed, extending increasingly past rear tergal margin, especially well so on segments 15-19; on segments 16-19, tips strongly curved mesad, posterior edge slightly oblique (Fig. 5A, C, F View Figure 5 ); paraterga very thin blunt blades in lateral view, a little thicker only on pore-bearing segments (Fig. 5D View Figure 5 ). Calluses on paraterga delimited by a sulcus both dorsally and ventrally. Paraterga 2 broad, horizontal, anterior edge angular, lateral edge with three evident incisions, one in anterior 1/3, middle one at midway, caudal incision near tip; anterior incision particularly evident. Paraterga 3 and 4 with two small incisions at lateral edge (Fig. 5A View Figure 5 ), one in anterior 1/3, the other at midway, anterior one also particularly evident. Following segments each with lateral edge showing an evident incision near front 1/3 (Fig. 5C View Figure 5 ). Ozopores evident, lateral, lying in an ovoid groove at about 1/3 metatergal length in front of posterior edge of metaterga (Fig. 5D View Figure 5 ). Transverse sulcus usually distinct (Fig. 5A, C, F View Figure 5 ), complete and visible on metaterga 5-18, deep, narrow, reaching bases of paraterga, line-shaped, clearly beaded at bottom. Stricture between pro- and metazonae wide, deep, clearly ribbed at bottom down to base of paraterga (Fig. 5A, C, F View Figure 5 ). Pleurosternal carinae complete crests on segment 2-4 (Fig. 5B View Figure 5 ), with anteriorly bulged crests and a sharp denticle caudally on segments 5-8 (♂, ♀), thereafter increasingly reduced and broken, remaining only a small sharp caudal tooth until segment 16 (♂) or 13 (♀), thereafter missing (Fig. 5B, D, E View Figure 5 ). Epiproct (Fig. 5E-G View Figure 5 ) conical, flattened dorsoventrally, subtruncate, with two evident apical papillae directed caudally, both pointed at tip; pre-apical papillae evident, lying close to tip. Hypoproct roundly subtrapeziform (Fig. 5G View Figure 5 ), small setiferous knobs at caudal edge well-separated and evident.

Sterna densely setose, without modifications (Fig. 5G View Figure 5 ); cross-impressions shallow; a deeply notched sternal lobe between ♂ coxae 4 (Fig. 5H, I View Figure 5 ). Legs long and slender, midbody ones ca 1.4-1.5 (♂) or 1.1-1.2 (♀) as long as body height; ♂ legs of segments 4-17 with prefemora distinctly swollen laterally; ♂ legs of segments 2-16 each with femur, postfemur, tibia and tarsus with particularly dense setae and carrying ventral microgranulations (Fig. 7C View Figure 7 ), tarsal brushes absent.

Gonopods (Figs 6 View Figure 6 , 7A, B View Figure 7 ) complex; coxa slightly curved caudad, sparsely setose distoventrally. Prefemorite as usual, densely setose, about 1/2 as long as femorite + “postfemoral” part. Femorite rather stout, suberect, expanded distad, showing a distinct mesal groove/hollow (g) and a prominent, rounded, dorso-apical lobe (m), apicolateral lobe (l) large, subtrapeziform, with a smooth apical margin, mostly delimited at base by a transverse sulcus, with process h short and triangular; process (z) rather short and simple, narrowly rounded at tip. Solenophore (sph) typically coiled, lamellar, expanded apically into a subtruncate lobe, almost fully sheathing a similarly long, flagelliform solenomere, with only its tip (sl) being exposed.

Name.

To honour Dr. Chirasak Sutcharit, Professor at the Department of Biology of the Chulalongkorn University, Bangkok, who participated in collecting the type series.

Remark.

Both new species described here have been found to occur syntopically (Fig. 9 View Figure 9 ).