Stylopauropus laminatus, Scheller, Ulf, 2014

Scheller, Ulf, 2014, New records of Pauropoda (Myriapoda) with descriptions of new taxa, Zootaxa 3866 (3), pp. 301-332 : 319

Stylopauropus laminatus n. sp.

Figs 30–37

Type specimen. Holotype: subad. 8 (♀), Thailand, Chiang Mai Prov., Doi Inthanon, 2100 m a. s. l., in litter, June 1, 1989, A. Bedos leg. Type specimen deposited in the Zoological Museum, University of Lund, Sweden.

Diagnosis. The small but distinct anal plate protruding backwards from between the setae st on the posterior part of the pygidial tergum has no equivalent in other species of the genus. Because the anal plate of the pygidial sternum has an extraordinary shape the relationships of this species cannot be traced at present.

Remarks. The occurrence of two anal plates, one on the sternum and the other on the tergum, has earlier been shown to occur in a few species in Tetramerocerata , family Diplopauropodidae with the genera Diplopauropus and Adelphopauropus ( Scheller 1988b, 2013, Scheller & Muchmore 1990), in all three species. Stylopauropus laminatus n. sp. may belong to a new genus, at present not possible to describe because the antennae are incomplete and all the bothriotricha are lacking in the material presented here.

Derivation of name. From the Latin laminus = thin plate, referring to the anal plate of the pygidial tergum.

Description. Length. 0.68 mm.

Head ( Fig. 30 ).Setae with oblique pubescence, partly dense, most tergal setae cylindrical, a 3 of 3rd row and lateral group setae pointed. Relative lengths of setae, 1st row: a 1 = 10; a 2 = 13; 2nd row: a 1 = 13, a 2 = a 3 = 11; 3rd row: a 1 = 13, a 2 =?; 4th row: a 1 = 17, a 2 =?, a 3 = 15, a 4 =?; lateral group: l 1 = 11, l 2 = l 3 = 13. The ratio a 1 /a-a 1 in 1st row 1.2, 2nd row 0.6, 3rd row 0.9, 4th row 1.5. Temporal organs broadest anteriorly, in tergal view 0.7 of shortest interdistance. Head cuticle glabrous.

Antennae ( Fig. 31 ). Very incomplete, flagella and seta q lacking. Segment 4 with 4 setae, p and p´ lacking, p '' and r both pointed, with oblique pubescence, length 15 µm. Tergal branch t cylindrical, 6.4 times as long as its greatest diameter and 1.1 times as long as the length of sternal branch s, that branch 3.4 times as long as its greatest diameter and with longish posterodistal truncation, Globulus g somewhat curved. 2.8 times as long as its greatest diameter; ≈11 bracts; capsule longer than wide. Diameter of g 1.2 times as long as the greatest diameter of t. Antennae glabrous.

Trunk ( Fig. 32 ). Setae of collum segment ( Fig. 32 ) with very short pubescence, submedian ones thick, clavate, sublateral ones furcate, main branch similar to submedian setae, secondary branch half of that length and inserted just outside the middle of the main branch. Sternite processes wide, subcylindrical, caps large thick. Process broad, two rounded anterior lobes separated by a V-shaped incision. Process and appendages glabrous.

Setae on anterior tergites as on median part on head, posteriorly growing longer. Tergite I with 4+4 setae, II–IV with 6+6, V with 6+4. Anterior row of setae on pygidial tergum with 4 setae, both d 1 and d 2. Tergites glabrous.

Bothriotricha. All lacking.

Legs ( Figs 33–35 ). Setae on coxa ( Fig. 33 ) and trochanter ( Fig. 34 ) of leg 9 furcate, branches thick cylindrical blunt, pubescence short, oblique; more anteriorly these setae leaf-shaped with rudimentary secondary branches. Tarsus of leg 9 ( Fig. 35 ) slender, tapering, 5.7 times as long as its greatest diameter. Proximal seta long, tapering, pointed, with distinct oblique pubescence, 0.4 of the length of tarsus and 3.9 times as long as cylindrical, distal seta. Cuticle of tarsus with distinct oblique pubescence on outer side, very short on inner side.

Pygidium ( Figs 36–37 ). Tergum: Posterior margin with distinct lobes around insertion points of setae st, in between straight. Setae of different shapes, a t thick, thickest in distal half, blunt, glabrous, a 2 and a 3 tapering, the former glabrous, the latter, pointed and with distinct oblique pubescence; their relative lengths: a 1 = 10, a 2 = 9, a 3 = 13, st = 9; a 1 and st almost straight, st also diverging, a 2 and a 3 curved inwards. Distance a 1 -a 1 0.6 of interdistance, distance a 1 -a 2 4.5 times as long as distance a 2- a 3; distance st-st as long as st and 1.5 times as long as distance a 1 -a 1. Cuticle glabrous.

Sternum: Posterior setae b 1 cylindrical, blunt, with short, dense, oblique pubescence, posterior margin with broad shallow indentation. Relative lengths of setae (pygidial a 1 = 10): b 1 = 18 and 19; these setae as long as to 1.1 times long as interdistance.

Anal plate of tergum linguiform, glabrous, length 0.3 of the length of the anal plate of the sternum; the latter broadest anteriorly, sub-quadrate, posterior margin with deep U-shaped indention, depth ¼ of the length of the plate, four posteriorly directed appendages, two small dentiform ones protruding from sternal side of the middle of lateral margins, and two large, clavate ones protruding from posterior margin of posterolateral branches, these appendages, as long as plate, with distinct oblique pubescence.

Figures

FIGURES 30 – 37. Stylopauropus laminatus n. sp., holotype, subad. 8 (♀). 30. Head, median and right part, tergal view. 31. Left antenna, sternal view. 32. Median and left part of collum segment, sternal view. 33. Seta on coxa of leg 8. 34. Seta on trochanter of leg 8. 35. Tarsus of leg 8. 36. Pygidium, median and left part, sternal view. 37. Pygidial tergum, median and right part, tergal view. Scale a: 35; b: 30 – 32; c: 33 – 34. 36 – 37.