Epanerchodus campus, Liu & Huo, 2020

Liu, Weixin & Huo, Qingbo, 2020, Two new species and a new record of polydesmoid millipedes from Jiangsu and Zhejiang provinces, eastern China (Diplopoda, Polydesmida), Zootaxa 4722 (1), pp. 41-49 : 42-45

Epanerchodus campus , new species

Figs 4–6

Type material: Holotype male ( SCAU), China, Jiangsu Province, Yangzhou City, Hanjiang district, Yangzhou University Wenhui Road Campus , 32°23’11.06”N, 119°25’27.74”E, 12 m a.s.l., 2017-XII-28, Qing-Bo Huo, Peng Gao leg. Paratypes: 1 male, 3 females ( SCAU), the same locality and data as holotype .

Etymology: This species epithet, campus , is used as a noun in apposition and emphasizes the type locality, i.e. the campus of Yangzhou University, Jiangsu Province.

Diagnosis: Adult males of E. campus n. sp. are distinct from other Epanerchodus species by the following combination of characters: (1) caudolateral corners of paraterga square ( Figs 5A, D ); (2) gonopodal femorite with a curved finger-shaped process medially and a smaller triangular tooth at its base; (3) endomere tip unequally bifid ( Fig. 6 ).

The new species seems to be especially similar to E. bishou n. sp. (from Zhejiang, China), but is distinguished by (1) male legs being devoid of sphaerotrichomes vs. male tibiae and tarsi with sphaerotrichomes in E. bishou n. sp.; (2) endomere bifid, with a small subapical lobe (l) ( Fig. 6 ) vs. endomere bifid, without lobe in E. bishou n. sp. ( Fig. 8B, C ).

Description: Based on type specimens. Lengths of both sexes ca 13–14 mm, widths of pro- and metazonae 1.2–1.4 and 2.3–2.4 mm, respectively. Coloration: generally grey to dark brownish ( Fig. 4 ). Body: Adults with 20 rings. Width: head <collum <ring 2 <3–4 <5 <6–15, thereafter (rings 16–19) body gradually tapering towards telson. Head: densely pilose, epicranial suture conspicuous ( Figs 5B, C ). Antennae long, reaching past middle of ring 3 (male) or 2 (female) when extended posteriorly, slightly clavate ( Figs 5 A–C).

Exoskeleton: Collum semi-circular, with three transverse rows of 4+4 setae and a faint lateral incision/denticle on each side. Paraterga broad ( Figs 5 A–E), midbody paraterga ca. 1.9x prozonite width. Paraterga 2–4 slightly upturned dorsally above a faintly convex dorsum, following paraterga flat and subhorizontal ( Figs 5C, E, I ). Caudolateral corners of paraterga nearly square, slightly projecting posteriorly past tergal margin, clearly acute only on rings 16–19 ( Figs 5A, D, G ). Integument shining ( Fig. 5 ), prozonae delicately alveolate. Limbus regularly denticulate. Constriction between pro- and metazonae narrow, shallow and smooth ( Fig. 5D ). Metatergal sculpture faint, with three irregular transverse rows of 3+3 setigerous polygonal bosses. Sulcus between front and middle rows of setae a little deeper than that between middle and caudal rows ( Figs 5A, D, G ). Tergal setae very short, present on rings 17–19 ( Fig. 5G ). Three or four faint setigerous incisions at lateral margins of poreless and pore-bearing rings, respectively. Pore formula normal: 5, 7, 9, 10, 12, 13, 15–19, ozopores evident, dorsal, clearly set off from lateral margin and located between last and penultimate marginal incisions ( Figs 5A, D, G ). Epiproct short, conical, pre-apical lateral papillae evident. Hypoproct subtrapeziform, with two setigerous papillae. Pleurosternal carinae present only on ring 2 in both sexes. Sterna sparsely setose, cross-shaped impressions (both axial and transverse) shallow, clearly broadened between male coxae 7 and 9 ( Figs 5B, E ).

Legs: long, but stout, about 1.5 (male) or 1.2 (female) times as long as body ring height, with neither sphaerotrichomes nor sternal cones, prefemora not bulging laterally.

Gonopods: ( Figs 5E , 6 A–B) Coxa large and squarish, as usual. Prefemur densely setose and about 1/3 as long as telopodite. Clivus, or distolateral ridge on femorite, prominent; femorite with a curved finger-shaped process (p) medially and a smaller triangular tooth (t) at base. Endomere (en) ribbon-shaped, unequally bifid, tip of longer branch being curved, with a small subapical lobe (l). Seminal groove (sg) starting mesally, distally recurved laterad near base of p, then turning laterobasad to run into an accessory seminal chamber, the latter opening on a hairy pulvillus. An exomere absent.

Figures

FIGURE 4. Epanerchodus campus n. sp. in nature A, B: two different male paratypes.

FIGURE 5. Epanerchodus campus n. sp., male paratype. A–C: anterior part of body, dorsal, ventral and lateral views, respectively D, F: midbody segments, dorsal, and lateral views, respectively E: gonopods in situ, ventral view G–I: posterior part of body, dorsal, ventral and lateral views, respectively.

FIGURE 6. Epanerchodus campus n. sp., male paratype. A, B: left gonopod, mesal and lateral views, respectively. Abbreviations: en = endomere; l = lobe; p = process; sg = seminal groove; t = tooth.

FIGURE 8. Epanerchodus bishou n. sp., male paratype from Tianmu Mountain Nature Reserve, Zhejiang. A: midbody leg 9, lateral view. B, C: right gonopod, lateral and mesal views, respectively. Abbreviations: en = endomere; p1 and 2 = processes 1 and 2; sg = seminal groove; t = tooth. Scale bar: A, 0.4 mm.