The Caucasus as a major hotspot of biodiversity: Evidence from the millipede family Anthroleucosomatidae (Diplopoda, Chordeumatida) Author Antić, Dragan Ž. Author Makarov, Slobodan E. text Zootaxa 2016 4211 1 1 205 journal article 37322 10.11646/zootaxa.4211.1.1 7af458af-d56d-44e3-a6f7-af97868175d9 1175-5326 272750 6B86C6BA-6AFE-4AAD-870D-04794C138D47 Georgiosoma bicornutum gen. et sp. nov. Figs 53–55 Diagnosis. As for the genus. Etymology. An adjective; the new species is named after a pair of horns on the anterior gonopods. Material studied (total: 2 males , 1 juvenile ). Holotype . GEORGIA : male, Cave " Grot Lagernaya 1" near Okureshi , 2000 m , 21 Sep.–14 Oct. 1983 , A. Tirakh & V.Y. Dolzhanskiy leg. ( ZMUM ρ3229). Paratypes (total: 1 male, 1 juveniles). Both from GEORGIA : 1 male , 1 juvenile , same data as holotype ( ZMUM ρ3230). Type locality. GEORGIA : Cave " Grot Lagernaya 1" near Okureshi. Description. Body with 30 segments (including telson) in adults. FIGURE 53. Georgiosoma bicornutum gen. et sp. nov. , holotype male habitus. Scale line = 1 mm. MEASUREMENTS. Males 20 mm long, vertical diameter of the largest pleurotergite 1.5 mm . COLORATION ( Fig. 53 ). Yellowish white. HEAD. Slightly concave in males. Labrum with three medial teeth and 4+4 labral and 2+2 supralabral setae. Promentum triangular, without setae. Lingual plates with 10+12 setae, on each plate arranged in 3 irregular rows. Stipites with ca 40+40 setae. Antennae elongated, 3.4 mm long in holotype . Length of antennomeres (in mm): I (0.13), II (0.25), III (1), IV (0.54), V (0.98), VI (0.26), VII (0.22) and VIII (0.02). Length/breadth ratios of antennomeres I–VII: I (1), II (1.3), III (6.7), IV (3.4), V (6), VI (1.6) and VII (2). Antennomeres II, IV, V, VI and VII with one, three, one, four and one sensillum, respectively. Number of ocelli 6, arranged in 3 rows in males. FIGURE 54. Georgiosoma bicornutum gen. et sp. nov. , paratype male. A. Leg 3. B. Leg 10. C. Leg 4. D. Leg 7. E. Leg 11. Scale lines = 0.2 mm. COLLUM. Narrower than head, with six macrochaetae. Anterior edge semi-circular, posterior margin gently concave. BODY SEGMENTS ( Fig. 53 ). Lateral keels well-developed. Macrochaetae medium-sized, outer longer than medial and inner, all trichoid. CIX (pleurotergite 15) ~ 0.75; MIX (pleurotergite 15) ~ 1.5; PIX (pleurotergite 15) ~ 0.6; MA (pleurotergite 15) ~ 135˚. 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. FIGURE 55. Georgiosoma bicornutum gen. et sp. nov. , paratype male gonopods. A. Anterior gonopods, anterior view. B. Anterior gonopods, lateral view. C. Anterior gonopods, posterior view. D. Posterior gonopods, posterior view. c = coxite; n = distal notch; t = telopodite; cp = coxal process; cv = coxal vesicle; lg = logitudinal groove; mp = medial part; pl = posterior lamella, rs = row of setae; sp = sternal plate; ss = sternal sac; sah = subtriangular, acuminate horns. Scale line = 0.3 mm. WALKING LEGS ( Fig. 53 ). 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. 54 ). Leg-pairs 3–7 enlarged. Leg-pairs 3 and 4 each with a basal external protrusion on prefemur. Leg-pair 5 with a strongly developed protrusion on prefemur. Leg-pair 6 without peculiarities. Coxae of leg-pair 7 with a well-developed, mesally curved horn, anteriorly with a subtriangular protrusion. Leg-pair 10 with coxal glands and well-developed coxal horns. Leg-pair 11 with coxal glands and short posterior coxal processes. ANTERIOR GONOPODS ( Fig. 55 A–C). Sternal plate ( sp ) anteriorly with a medial, triangular, acuminate, hairy, sternal sac ( ss ). Coxal processes ( cp ) fused, only distally with a notch ( n ) and an anterior longitudinal groove ( lg ), forming a rounded shield with two well-developed, subtriangular and acuminate horns ( sah ) in anterior and posterior views. These horns connected to posterior lamellae ( pl ) supporting denticles and setae in upper half. Mediodistal parts ( mp ) with denticulate upper edges and mesal edges folded inside and forming a denticulate winglike structure. Posteriorly, two diagonal rows of setae ( rs ) present. POSTERIOR GONOPODS ( Fig. 55 D). Coxites ( c ) divided. Telopodites ( t ) present on posterolateral side, clothed with setae. Coxal processes ( cp ) horn-like, clothed with minute setae. Coxal vesicles ( cv ) present on anterior side. Notes. This species is only known from a cave and shows some troglomorphic features such as reduced body pigmentation and number of ocelli, a larger number of setae on the gnathochilarium, as well as elongated antennae and walking legs.