Leucogeorgia borealis, Antić & Reip, 2020

Antić, Dragan Ž. & Reip, Hans S., 2020, The millipede genus Leucogeorgia Verhoeff, 1930 in the Caucasus, with descriptions of eleven new species, erection of a new monotypic genus and notes on the tribe Leucogeorgiini (Diplopoda: Julida: Julidae), European Journal of Taxonomy 713, pp. 1-106 : 28-32

Leucogeorgia borealis sp. nov.

urn:lsid:zoobank.org:act:D8CFFCD0-8D33-42A0-B7FD-E8FDE92E99E2

Figs 16–18 , 56–57

Diagnosis

This species belongs to the group of Leucogeorgia spp. without modified mouthparts and with teeth on the mesomeral claw (vs absent in L. golovatchi sp. nov., L. lobata sp. nov. and L. prometheus sp. nov.). Leucogeorgia borealis sp. nov. differs from L. abchasica , L. satunini and L. gioi sp. nov. by having a stout mesomeral claw (vs elongate and slender in L. abchasica , L. satunini and L. gioi sp. nov). Leucogeorgia borealis sp. nov. differs from L. oculata sp. nov. by having a strongly serrate mesomeral lamella without a posterior rise (vs lamella non-serrate and with a posterior rise in L. oculata sp. nov.), and in the absence both of pigmentation and ommatidia, and the presence of metazonal setae (vs a pigmented body, ommatidia present and metazonal setae absent in L. oculata sp. nov.).

Etymology

From the Latin ʻ boreas ʼ (= ʻnorthʼ), reflecting its having the northernmost species in the genus.Adjective.

Type material

Holotype

RUSSIA • ♂; Krasnodar Province, near Goryachiy Klyuch, NW karst area of Greater Caucasus, Fanagoriyskaya (= Bolshaya Fanagoriyskaya, = Psekupskaya) Cave ; 44.47° N, 38.98° E; 3 Nov. 1943; J. Birstein leg.; ZMUM.

Paratypes

RUSSIA • 1 ♂, 1 ♀, 2 juvs; same collection data as for holotype but 8 Jul. 1961; S.I. Ljovuschkin leg.; ZMUM • 1 juv.; same collection data as for holotype but 19 May 1983; S.I. Golovatch leg.; ZMUM • 1 ♀; same collection data as for holotype but 20 Sep. 1968; ZMUM .

Description

SIZE AND NUMBER OF BODY RINGS. Holotype male 24 mm long, vertical diameter of largest body ring 1.5 mm, body with 43 podous rings + 1 apodous ring + telson. Paratype male 28 mm long, vertical diameter of largest body ring 1.55 mm, body with 49 podous rings + 2 apodous rings + telson. Paratype females 21 and 24 mm long, vertical diameter of largest body ring 1.4–1.5 mm, body with 37 or 44 podous rings + 1 apodous ring + telson.

COLOUR ( Fig. 16 ). Yellowish white in alcohol.

HEAD ( Figs 16B , 17C ). Without ommatidia. Frontal setae absent. Labrum with three labral teeth, four supralabral setae and 17 labral setae in paratype male. Gnathochilarium with a rhomboid promentum; lamellae linguales with 4+4 setae, stipites with 3+3 distolateral and 5+6 medial setae. Antennae 1.9 mm long in smaller paratype female, their length ca 140% of vertical diameter of largest body ring. Lengths of antennomeres I–VIII (in mm): 0.13 (I), 0.45 (II), 0.36 (III), 0.30 (IV), 0.40 (V), 0.18 (VI), 0.06 (VII) and 0.02 (VIII). Length/width ratio of antennomeres I–VII: 0.8 (I), 3 (II), 2.4 (III), 2 (IV), 2.7 (V), 1 (VI) and 0.5 (VII). Antennomeres V and VI each with a terminal corolla of large sensilla basiconica bacilliformia; antennomere VII with a terminal corolla of small sensilla basiconica bacilliformia.

BODY RINGS ( Fig. 16E ). Entire metazonal area with longitudinal striations. Length of midbody setae ca 5% of vertical diameter of rings.

TELSON ( Fig. 16C ). Epiproct with a short and blunt preanal process, covered with dorsal and lateral setae. Paraprocts rounded, setose. Hypoproct without any modifications.

LEGS IN MALES. First pair of legs modified, hook-shaped ( Figs 17 A–B, 18D–E), with three complete podomeres; coxa with two setae; prefemur with four setae; femur, postfemur and tibiotarsus coalesced; femur with two setae; postfemur with one seta; tibiotarsus with a prominent distal lobe (tarsal remnant). Tip slightly tuberculated. Postfemoral and tibial ventral pads well developed on anterior legs, then gradually disappearing towards posterior legs.

VENTRAL MARGIN OF MALE BODY RING 7 ( Fig. 16D ). Poorly developed, low, rounded in lateral view.

PENES ( Fig. 18C ). In form of a short trapezoid, apically with two small subtriangular lobes.

GONOPODS ( Figs 17D , 18 A–B). Promere (p) long and slender, with a flagellum (f); apical part spatulate, with denticulate margins; basal half with two developed ridges. Mesomere (m) with a well-developed, robust and denticulate mesomeral claw (mc); mesomeral lamella (ml) convex in central part, distal margin serrate, posterior part finely fimbriate. Opisthomere (o) bipartite. Anterior branch of o with a solenomere (s), with a medium-sized tip, and a well-developed and fimbriate velum (v). Posterior branch

of o in form of a shield-like protective lamella (pl). Mesomere and opisthomere connected basally through an accessory membrane (am).

Distribution

Known only from its type locality ( Fig. 57 , blue triangle).

Remarks

This is the northwesternmost record of the entire genus.

Figures

Fig. 16. Leucogeorgia borealis sp. nov., types from Fanagoriyskaya Cave (ZMUM). A. Paratype ♀, habitus, lateral view. B. Paratype ♀, anterior part of body, lateral view. C. Paratype ♂, posterior part of body, lateral view. D. Holotype ♂, body ring 7, lateral view. E. Paratype ♀, midbody rings, lateral view. Arrow indicated metazonal seta. Scale bars: 1 mm.

Fig. 17. Leucogeorgia borealis sp. nov., paratype ♂ from Fanagoriyskaya Cave (ZMUM). A. Leg-pair 1, anterior view. B. Right leg 1, lateral view. C. Head, ventral view. D. Left gonopods, mesal view. Abbreviations: am = accessory membrane; f = flagellum; m = mesomere; mc = mesomeral claw; ml = mesomeral lamella; o = opisthomere; p = promere; pl = protective lamella; s = solenomere; v = velum. Scale bars: A–B = 0.05 mm; C = 0.2 mm; D = 0.1 mm.

Fig. 18. Leucogeorgia borealis sp. nov., holotype ♂ from Fanagoriyskaya Cave (ZMUM). A. Right gonopods, mesal view. B. Right gonopods, lateral view. C. Penes, posterior view. D. Leg-pair 1, anterior view. E. Right leg 1, lateral view. Scale bar: 0.1 mm.

Fig. 56. General distribution of the Caucasian leucogeorgiinines. The white dashed line hypothetically indicates the boundary between the northwestern and southeastern groups of species of the genus Leucogeorgia Verhoeff, 1930.

Fig. 57. Distribution of the northwestern group of the genus Leucogeorgia Verhoeff, 1930.