Leucogeorgia golovatchi, 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 : 37-41

Leucogeorgia golovatchi sp. nov.

urn:lsid:zoobank.org:act:AFC4B93A-128A-4FF6-9E97-726F4DDE4CA1

Figs 22–24 , 56 , 58

Diagnosis

This species belongs to the group of Leucogeorgia spp. with neither modified mouthparts nor teeth on the mesomeral claw (vs teeth present in L. abchasica , L. borealis sp. nov., L. gioi sp. nov., L. oculata sp. nov. and L. satunini ). Leucogeorgia golovatchi sp. nov. differs from L. lobata sp. nov. by the absence of a strongly developed lobe on the mesomeral lamella (vs presence of a strongly developed lobe in L. lobata sp. nov.). Leucogeorgia golovatchi sp. nov. differs from L. prometheus sp. nov. by both a shorter mesomeral claw and a long solenomere clearly exceeding the height of the mesomeral lamella (vs a longer mesomeral claw and a short solenomere not exceeding the height of the mesomeral lamella in L. prometheus sp. nov.). Additionally, L. golovatchi sp. nov. clearly differs from all other congeners by having strongly developed ventral lobes on body ring 2 in both sexes (vs absence of such lobes in all other congeners).

Etymology

This new species is dedicated to Sergei Golovatch, one of the collectors, a well-known diplopodologist worldwide, and our good friend and colleague. His collection of millipedes from the Caucasus, now in ZMUM, is one of the largest and most complete. Noun in the genitive case.

Material examined

Holotype

CENTRAL-WEST GEORGIA – Racha-Lechkhumi • ♂; Ambrolauri District , near Gogoleti, Tsakhi (= Gogoleti) Cave ; 42.54° N, 42.90° E; 30 Jul. 1939; J. Birstein leg.; ZMUM.

Paratypes

CENTRAL-WEST GEORGIA – Racha-Lechkhumi • 8 ♂♂, 1 ♀, 6 juvs; same collection data as for holotype; ZMUM • 1 ♂; same collection data as for holotype; IZB • 1 ♂; same collection data as for holotype; SMNG ; • 7 ♂♂, 3 ♀♀, 7 juvs (mainly fragmented); same collection data as for holotype but 9 Aug. 1974; S.I. Golovatch leg.; ZMUM .

Description

SIZE AND NUMBER OF BODY RINGS. Holotype male 25 mm long, vertical diameter of largest body ring 1.6 mm, body with 50 podous rings + 1 apodous ring + telson. Paratype males 22–29 mm long, vertical diameter of largest body ring 1.3–1.8 mm, body with 43–52 podous rings + 0–2 apodous rings + telson. Paratype females 21–29 mm long, vertical diameter of largest body ring 1.3–1.8 mm, body with 46–50 podous rings + 1 apodous ring + telson.

COLOUR ( Fig. 22 ). Yellowish white in alcohol.

HEAD ( Figs 22B , 23C ). Without ommatidia. Frontal setae absent. Labrum with three labral teeth, four supralabral setae and 15 labral setae. Gnathochilarium with rhomboid promentum. Lamellae linguales with 5+5 setae, stipites with 3+3 distolateral and 11+11 medial setae. Antennae 2.3 mm long in holotype

male, their length ca 140% of vertical diameter of largest body ring. Lengths of antennomeres I–VIII (in mm): 0.12 (I), 0.47 (II), 0.41 (III), 0.4 (IV), 0.46 (V), 0.29 (VI), 0.12 (VII) and 0.03 (VIII). Length/width ratio of antennomeres I–VII: 0.8 (I), 3 (II), 3 (III), 2.7 (IV), 2.4 (V), 1.6 (VI) and 0.9 (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. 22 D–F). Entire metazonal area with longitudinal striations. Length of midbody setae ca 5% of vertical diameter of rings. Body ring 2 with strongly developed ventral lobes ( Fig. 22B , E–F), rounded in lateral view.

TELSON ( Fig. 22C ). Epiproct with a very short and blunt preanal process, covered with dorsal and lateral setae. Paraprocts rounded, with numerous setae. Hypoproct without any modifications.

LEGS IN MALES. First pair of legs modified, hook-shaped ( Figs 23 A–B, 24D–E), with three complete podomeres; coxa with one seta; prefemur with 8–10 setae; femur, postfemur and tibiotarsus coalesced; femur with 2–3 setae; postfemur with one seta. Tibiotarsus with a short distal lobe (tarsal remnant). Tip slightly tuberculated. Postfemoral and tibial ventral pads well-developed on anterior legs, then gradually disappearing towards posterior legs.

PENES ( Fig. 24C ). In form of a short trapezoid, apically with two small subtriangular lobes.

VENTRAL MARGIN OF MALE BODY RING 7 ( Fig. 22G ). Small, rounded in lateral view.

GONOPODS ( Figs 23D , 24 A–B). Promere (p) long and slender, with a flagellum (f); apical part with poorly denticulated margins; basal half with two developed ridges. Mesomere (m) with a slender mesomeral claw (mc) lacking teeth; mesomeral lamella (ml) gradually decreasing in height posteriad, distal margin serrate, posterior part finely fimbriate. Opisthomere (o) bipartite. Anterior branch of o with a solenomere (s) with a long tip exceeding posterior part of lamella, 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 with an accessory membrane (am).

Distribution

Known only from its type locality ( Fig. 58 , orange triangle).

Figures

Fig. 22. Leucogeorgia golovatchi sp. nov., type ♂♂ from Tsakhi Cave (ZMUM) (A–D: holotype; E–G: paratype). A. Habitus, lateral view. B. Anterior part of body, lateral view. C. Posterior part of body, lateral view. D. Midbody rings, lateral view. E. Body ring 2, lateral view. F. Body ring 2, anterior view. G. Body ring 7, lateral view. Scale bars: A–D = 1 mm; E–G = 0.5 mm.

Fig. 23. Leucogeorgia golovatchi sp. nov., paratype ♂ from Tsakhi Cave (ZMUM). A. Leg-pair 1, anterior view. B. Right leg 1, lateral view. C. Head, ventral view. D. Right 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, C–D = 0.1 mm; B = 0.05 mm.

Fig. 24. Leucogeorgia golovatchi sp. nov., type ♂♂ from Tsakhi Cave (ZMUM). A. Holotype, right gonopods, mesal view. B. Holotype, left gonopods, lateral view. C. Paratype, penes, posterior view. D. Paratype, leg-pair 1, anterior view. E. Right leg 1, lateral view. Scale bar: 0.3 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. 58. Distribution of the southeastern group of the genus Leucogeorgia Verhoeff, 1930 and the species Martvilia parva gen. et sp. nov.