Golovatchosoma bacillichaetum

Antić, Dragan Ž. & Makarov, Slobodan E., 2016, The Caucasus as a major hotspot of biodiversity: Evidence from the millipede family Anthroleucosomatidae (Diplopoda, Chordeumatida), Zootaxa 4211 (1), pp. 1-205 : 8-14

Golovatchosoma bacillichaetum gen. et sp. nov.

Figs 2–6

Diagnosis. This new species differs from the only other known congener, G. trichochaetum sp. nov., by the presence of short and bacilliform macrochaetae on most of pleurotergites, as well as in some details of structures of the anterior gonopods, in particular the shape of the anterior sternal sac (bilobed vs. unipartite). Male leg-pair 7 with a posterior coxal process.

Etymology. To emphasize the bacilliform macrochaetae on body segments.

Material studied (total: 9 males, 8 females). Holotype. ARMENIA: male, Kafan District , Shikahoh Nature Reserve, Tsav, 100 m asl, Quercus , Fagus , Carpinus forest, litter, 29 Apr. 1983, S. Golovatch leg. ( ZMUM ρ3218).

Paratypes (total: 8 males, 8 females). All from ARMENIA, Kafan District, Shikahoh Nature Reserve: 1 male, same data as holotype ( ZMUM ρ3219) ; 6 males, 7 females (ZMUM ρ3220), 1 male, 1 female (IZB), village Shikahoh, 900–950 m, Quercus , Fagus , Carpinus forest near spring, litter, logs and under stones, 28 Apr. 1983, S. Golovatch leg.

Type locality. ARMENIA: Kafan District , Shikahoh Nature Reserve, Tsav, 100 m asl, Quercus , Fagus , Carpinus forest.

Description. Body with 30 segments (including telson) in adults.

MEASUREMENTS. Males 7–8 mm long, vertical diameter of the largest pleurotergite 0.5–0.6 mm. Females 7– 8.5 mm long, vertical diameter of the largest pleurotergite 0.6–0.65 mm.

COLORATION ( Fig. 2 ). Pale yellowish. Some specimens dark violet, probably due to a specific diet.

HEAD. Without frontal depression in males. Labrum with three medial teeth and 5+4 labral and 2+2 supralabral setae. Promentum triangular, without setae. Lingual plates with 4+4 setae, on each plate arranged in one row. Stipites with ca 20+20 setae. Antennae 1.2 mm long in paratype male. Length of antennomeres (in mm): I (0.06), II (0.11), III (0.3), IV (0.18), V (0.31), VI (0.12), VII (0.11) and VIII (0.01). Length/breadth ratios of antennomeres I– VII: I (1), II (1.4), III (4.3), IV (2.3), V (2.8), VI (1.2) and VII (1.6). Antennomeres II, IV, V, VI and VII with one, three, one, four and one sensillum, respectively. Number of ocelli 4–7, arranged in 3–4 rows in males; 5–8 in 4 rows in females.

COLLUM. Narrower than head, with six macrochaetae. Anterior edge semi-circular, posterior margin gently concave.

BODY SEGMENTS ( Figs 2 , 3 ). Lateral keels like lateral swellings. Macrochaetae on the first 5–6 pleurotergites and on pleurotergites 28 and 29 medium-sized and trichoid, remaining pleurotergites with short bacilliform macrochaetae. CIX (pleurotergite 15) ~ 0.7; MIX (pleurotergite 15) ~ 1.2; PIX (pleurotergite 15) ~ 0.5; MA (pleurotergite 15) ~ 120˚.

TELSON. Epiproct with a pair of spinnerets and 3+3 setae (1+1 paramedian, 2+2 marginal). Hypoproct with 1+1 apical setae. Paraprocts with 3+3 marginal setae.

WALKING LEGS. In both sexes, leg-pairs 1 and 2 with tarsal combs; prefemora with several long and robust setae; femora and postfemora with a group of several long and robust setae.

MALE SEXUAL CHARACTERS ( Fig. 4 ). Leg-pairs 3–7 enlarged. Leg-pairs 3 and 4 each with a basal exterior protrusion on prefemur. Leg-pairs 5 and 6 without peculiarities. Leg-pair 7 with a well-developed rounded protrusion carrying several long setae and one well-developed posterior horn on coxae; prefemora with a posterior basal protrusion. Leg-pair 10 with coxal glands, without other peculiarities. Leg-pair 11 with coxal glands and a posterior coxal horn.

ANTERIOR GONOPODS ( Figs 5 A–C, 6). Sternal plate with a bilobed anterior sternal sac (ss) consisting of two lateral parts clothed with small setae apically and of one medial, low part also carrying small setae. Gonopods consisting of a medial syncoxal (s) part and two lateral parts (lp). Syncoxite anteriorly only with a distal (dg) and a basal (bg) groove; apically with setae; posteriorly with lateral and medial rows of setae, the latter row connected by a pair of lamellae (l) to a robust, subtriangular, medial, posterior projection (ppr). A row of setae (rs) traced on both lateral sides of projection base. Lateral parts (lp) lamellar, with denticulate lateral edges; posteriorly with a row of setae (rs).

POSTERIOR GONOPODS ( Fig. 5 D). Coxites (c) divided. Telopodites (t) well-developed, two-segmented, orientated laterad, setose. Coxal processes (cp) placed mesally. Coxal vesicles (cv) present at base on posteromesal side.

Distribution. Armenia (Shikahoh Nature Reserve) ( Fig 166 , red asterisk).

Figures

FIGURE 2. Golovatchosoma bacillichaetum gen. et sp. nov., paratype male. A. Habitus. B. Body segments with bacilliform macrochaetae. Scale lines = 1 mm.

FIGURE 3. Golovatchosoma bacillichaetum gen. et sp. nov., paratype male. A. Pleurotergite 15, posterior view. B. Pleurotergites 13 – 15, lateral view. C. and D. Bacilliform macrochaeta. E. Pleurotergites 13 – 15, dorsal view.

FIGURE 4. Golovatchosoma bacillichaetum gen. et sp. nov., holotype male. A. Leg 3. B. Leg 4. C. Leg 7. D. Leg 11. Scale lines = 0.2 mm.

FIGURE 5. Golovatchosoma bacillichaetum gen. et sp. nov., holotype male gonopods. A. Anterior gonopods, anterior view. B. Anterior gonopods, posterior view. C. Anterior gonopods, lateral view. D. Posterior gonopods, posterior view. c = coxite; l = lamellae; s = medial syncoxal part; t = telopodite; bg = basal groove; cp = coxal process; cv = coxal vesicle; dg = distal groove; lp = lateral part; rs = row of setae; ss = sternal sac; ppr = posterior projection. Scale line = 0.2 mm.

FIGURE 6. Golovatchosoma bacillichaetum gen. et sp. nov., paratype male, anterior gonopods gonopods. A. Anterior view. B. Anterolateral view. C. and D. lateral view. E. and F. Posterior view. l = lamellae; s = medial syncoxal part; bg = basal groove; dg = distal groove; lp = lateral part; rs = row of setae; ss = sternal sac; ppr = posterior projection.

FIGURE 166. Distribution of the Cucasian Anthroleucosomatidae: the Alloiopus and the Enghoffiella complexes.