Caucaseuma elephantum, Antić, Dragan Ž. & Makarov, Slobodan E., 2016

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 : 29-32

Caucaseuma elephantum sp. nov.

Figs 18–20

Diagnosis. Differs from the other Caucaseuma species by the general shape of the anterior shields of the anterior gonopods; by the presence of two bifurcated projections/processes (bp1 and bp2), one below the other, on the anterior gonopods; and by the presence of a small and simple posterior coxal process on male leg-pair 7.

Etymology. The new species is named after its type locality, the Southern Elephant Cave; at the same time, this is one of the largest Caucaseuma species.

Material studied (total: 1 male). Holotype. RUSSIA: male, Peshchera Yuzhnyi Slon—“ Southern Elephant”, Mt Dzentu , Karachaevo-Cherkessia Republic , 1784 m asl, Efremova leg. ( ZMUM ρ3253).

Type locality. RUSSIA: Cave Yuzhnyy Slon—“ Southern Elephant Cave”, Mt Dzentu, Karachaevo-Cherkessia Republic , 1784 m asl.

Description. Body with 30 segments (including telson).

MEASUREMENTS. Holotype male 20 mm long, vertical diameter of the largest pleurotergite 1.2 mm.

COLORATION ( Fig. 18 ). Yellowish white.

HEAD. Without frontal depression in male. Labrum with three medial teeth and 5+5 labral and 2+2 supralabral setae. Gnathochilarium densely setose. Promentum triangular, with 10 setae. Lingual plates with 26+23 setae arranged in irregular rows. Stipites densely setose. Antennae long, densely setose; 3.03 mm long in holotype. Length of antennomeres (in mm): I (0.1), II (0.31), III (0.8), IV (0.41), V (0.85), VI (0.32), VII (0.2) and VIII (0.04). Length/breadth ratios of antennomeres I–VII: I (0.8), II (1.9), III (6.6), IV (2.9), V (4.7), VI (1.8) and VII (1.2). Antennomeres II, IV, V, VI and VII with one, three, one, four and one sensillum, respectively. Number of ocelli 11–12, arranged in 3–4 rows in holotype.

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

BODY SEGMENTS ( Fig. 18 ). Lateral keels well-developed. Macrochaetae long and trichoid. CIX (pleurotergite 15) ~ 0.9; MIX (pleurotergite 15) ~ 2.3; PIX (pleurotergite 15) ~ 0.5; MA (pleurotergite 15) ~ 93˚.

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 ( Fig. 18 ). Densely setose. 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. 19 ). Leg-pairs 3–7 enlarged. Leg-pairs 3 and 4 each with a basal external protrusion on prefemur. Leg-pairs 5 and 6 without any peculiarities. Leg-pair 7 with nearly rounded coxae, a small and simple posterior process placed in the middle of each coxa and associated with one long, exterior seta. Legpairs 10 and 11 with coxal glands; leg-pair 10 with external basal denticles on prefemur; leg-pair 11 with external and ventral denticles on prefemur.

ANTERIOR GONOPODS ( Fig. 20 A–C). Anteriorly, sternal plate (sp) [= v sensu Strasser (1970): 201, figs 1 and 2] with a medial, triangular, hairy, tapering sternal sac (ss) [= s sensu Strasser (1970): 201, figs 1 and 2]. Anterior coxal processes (cp) shield-like [= sc sensu Strasser (1970): 201, figs 1 and 2], partially (basally) fused, divided distally. Shields finger-shaped apically (a) and curved posteriorly. Mesal edges folded inside and forming two bifurcated projections/processes (bp1 and bp2), one below the other. These projections extending beyond rear edge of posterior coxal processes (pp) [= te sensu Strasser (1970): 201, 202 figs 2 and 3]. Upper bifurcated projection (bp1) thinner, curved downward and laterad, while lower bifurcated projection (bp2) thicker and orientated downward. Upper bp1 divided medialy, while bp2 seems to be unique. Posterior coxal processes (pp) characterized by the presence of several lamellar structures. Anterior parts (app) of posterior coxal processes higher, as high as apical constrictions of shields. These parts tapering apically and slightly curved anteriorly. In lateral view, fore edge of this part smooth, rare edge being denticulate. Laterally, this part showing one lamella (l1), starting subapically, at halfway with a lateral, massive, spoon-shaped, probably protective lamella (prl). Anterior part (app) of posterior coxal processes apically in the form of a finger in posterior view. Mesal edges of posterior coxal processes charaterized by a lamellar structure in upper half, while lower halves covered by numerous setae. The opening for sperm transfer is possibly located at the border between the lamellar and setose parts. Two lobes covered by numerous short setae located at base of posterior coxal processes, these lobes possibly representing remnants of coxal vesicles (cv) [= w sensu Strasser (1970): 202, fig 3].

POSTERIOR GONOPODS ( Fig. 20 D). Coxites (c) [= co sensu Strasser (1970): 203, fig 5] completely divided. Laterally and posteriorly with telopodital remnants (t) [= te sensu Strasser (1970): 203, figs 5 and 6], with small a tongue. Coxal vesicles (cv) [= w sensu Strasser (1970): 203, figs 5 and 6] present anteriorly. Both coxites bearing a pair of flagelliform coxal processes (cp) [= x and y sensu Strasser (1970): 203, figs 5 and 6].

Distribution. Russia (known only from Peshchera Yuzhnyy Slon—“ Southern Elephant Cave”) ( Fig. 168 , orange circle).

Notes. This species is known only from a cave and shows certain troglomorphic features such as reduced body pigmentation and a somewhat reduced number of ocelli, a densely setose gnatochilarium where even the promentum bears 10 setae, as well as elongated antennae and walking legs.

Figures

FIGURE 18. Caucaseuma elephantum sp. nov. holotype male habitus. Scale lines = 1 mm.

FIGURE 19. Caucaseuma elephantum sp. nov. holotype male. A. Leg 3. B. Leg 4. C. Leg 7. Scale lines = 0.4 mm.

FIGURE 20. Caucaseuma elephantum sp. nov. holotype male gonopods. A. Anterior gonopods, anterior view. B. Anterior gonopods, lateral view. C. Anterior gonopods, posterior view. D. Posterior gonopods, posterior view. a = apical constriction of the shield; c = coxite; t = telopodite; cp = anterior coxal process / coxal process; cv = coxal vesicle; l 1 = lamella; pp = posterior coxal process; sp = sternal plate; ss = sternal sac; app = anterior part of the posterior coxal process; bp 1 = uper bifurcated projection; bp 2 = lower bifurcated projection; prl = spoon-shaped protective lamella. Scale line = 0.3 mm.

FIGURE 168. Distribution of the Caucasian Anthroleucosomatidae: the Caucaseuma complex.