A new dwarf schendylid centipede (Chilopoda: Geophilomorpha: Schendylidae) with a low number of legs from Serbia, Balkan Peninsula Author Stojanović, Dalibor Z. University of Belgrade-Faculty of Biology, Institute of Zoology, Studentski Trg 16, 11000 Belgrade, Serbia Author Šević, Mirko 0000-0002-1979-9516 University of Belgrade-Faculty of Biology, Institute of Zoology, Studentski Trg 16, 11000 Belgrade, Serbia mirko.sevic@bio.bg.ac.rs Author Makarov, Slobodan E. 0000-0002-4365-8182 University of Belgrade-Faculty of Biology, Institute of Zoology, Studentski Trg 16, 11000 Belgrade, Serbia slobodan@bio.bg.ac.rs text Zootaxa 2024 2024-03-07 5419 3 401 418 http://dx.doi.org/10.11646/zootaxa.5419.3.5 journal article 10.11646/zootaxa.5419.3.5 1175-5326 10791864 DB42F853-1755-48E1-A1CB-0147C0D7998F Schendyla antici Stojanović , new species Figs 1C – 6 Material studied . Holotype : male (IZB ChG0151), SERBIA , Mt. Medvednik , Kulina hill, near mountain hut “Krušik” (coordinates 44.20620 , 19.65880 ; elevation about 830 m a.s.l. ; Fig. 1A, B ), old beech forest, extracted from the soil, 2 August 2011 , D. Antić leg. Paratypes : five males (IZB ChG0152, IZB ChG0153, NHMW MY10371 , NMNHS-Myriapoda-10830, and VNR 021239-1b) , nine females (IZB ChG0154–IZB ChG0159, NHMW MY10372 , NMNHS-Myriapoda-10831, and VNR 021239-1a), same locality as in the holotype , 8 June 2021 , old beech forest, extracted from the soil, D. Stojanović , M. Šević & D. Antić leg. Additional non-type material : three juvenile females (IZB ChG0160), all on adolescens 3 stage, same data as in paratypes ; two males (IZB ChG0162 A, B) and five females (IZB ChG0163 A–E), same locality, extracted from the soil, 14 November 2023 , D. Stojanović & M. Šević leg. FIGURE 1. A , B . Type locality. C . Schendyla antici sp. nov. , paratype ♀ (NMNHS-Myriapoda-10831). A . Position of the type locality on the map of Serbia. B . Habitat, old beech forest on Kulina hill, Mt. Medvednik (photo D. Antić). C . Habitus, dorsal, somewhat lateral view. Scale bar : 1 mm. FIGURE 2. Schendyla antici sp. nov. , living specimens, habitus. A , B . Non-type ♂ (IZB ChG0162 A). C , D . Non-type ♀ (IZB ChG0163 A). E , F . Non-type ♀ (IZB ChG0163 B). Photographs : D. Antić. Name. The new species is named in honour of our close friend and colleague, the well-known Serbian myriapodologist Dr. Dragan Antić ( Belgrade , Serbia ), who collected the first specimen of the new species ( holotype ) and participated in the collection of most of the remaining specimens. The epithet, a name in the genitive case, is a patronym . Diagnosis. The unique combination of characters clearly distinguishes the new species from its congeners: 29–31 leg-bearing segments; small body size (less than 8 mm ); labrum with 10 median and three moderately longer and pointed lateral denticles on each side; minute denticles on forcipular trochanteroprefemora (small and weakly noticeable), without denticles on femora and tibiae, and with small basal denticle on tarsungulum; mandibular dentate lamella undivided, with 6–8 teeth (usually eight); pretarsus of second maxillae slightly flattened distally, without filaments; absence of ventral pore-fields in all sternites; last terminal article of ultimate legs as small tubercle, armed with minute rudimentary apical claw and with few accessory spines close to the basis of the claw. The low number of leg-bearing segments clearly distinguishes the new species from all other species of the genus, with the exception of poorly known Schendyla verneri ( Folkmanová & Dobroruka, 1960 ) , which has 31 leg-bearing segments, recorded in all studied specimens. However, the new species can be easily distinguished from this species based on more teeth on mandibular dentate lamella (6–8 vs. three in S. verneri ), the complete absence of sternal pores (vs. presence of a few scattered pores in anterior sternites in S. verneri ), and the presence of rudimentary claw on ultimate legs (vs. without claw in S. verneri ). Description. Number of leg pairs and body size : Holotype male with 29 pairs of legs, body length 7.2 mm . All paratype males with 29 pairs of legs, body length 4.8–6.6 mm (average 5.6 mm ); all paratype females with 31 pairs of legs, body length 4.5–8.0 mm (average 6.3 mm ). Non-type juvenile females also with 31 pairs of legs, and body length around 4 mm . Additional non-type material follows the similar pattern, both males with 29 leg-bearing segments and a body length of 5.5–7.0 mm (average 6.3 mm ); all females with 31 leg-bearing segments, with a body length of 6.4–7.7 (average 7.0 mm). Colouration : Whitish, with pale yellowish zones on somewhat sclerotized parts of the head, mouthparts, forcipular segment, antennae and apical claws of walking legs ( Figs 1C , 2 ). Antennae : Relatively short, ca . 1.4–2.3 (usually 1.8) times longer than cephalic plate, slightly longer in males (1.5–2.3; usually 1.8) than in females (1.4–2; usually 1.7). Basal article ca . 1.5 times wider than long ( Fig. 3A ). Terminal article without any dents or flattening on apex, completely rounded, and ca . three times longer than penultimate one ( Fig. 3A, B ); in both sexes. Chaetotaxy fairly uniform along the antennae ( Fig. 3A ), without differences between dorsal and ventral sides. In adults of both sexes, terminal article with 7–9, usually 8 distolateral and 3 or 4 distomesal sensilla basiconica ( Fig. 3A, B ), with more prominent sensilla trichodea between. All other articles with only sensilla trichodea. Cephalic capsule : Oval, ca . 1.3–1.5 (usually 1.4) times longer than wide, with evenly distributed setae on surface ( Fig. 4A ). Forcipular segment : Forcipular tergite trapeziform, slightly narrowed anteriad, with a flat anterior side. Forcipular coxosternite ca . 1.2–1.3 times wider than long, somewhat wider in comparison to cephalic capsule ( Figs 3C , 4B ). Anterior margin of coxosternite without denticles, slightly concave. Coxopleural sutures ending nearby coxosternal condyles, somewhat laterally; chitin lines absent. Shape and chaetotaxy of forcipular coxosternite and telopodites as in Fig. 4B . Small, barely noticeable proximal denticles present on forcipular trochanteroprefemora; femora and tibiae without denticles ( Fig. 4C ). Forcipular tarsungulum curved, armed with small basal denticle and without denticle-like projections along inner side. The straight duct of poison gland opening externally near apical end of tarsungulum; calyx of poison gland follicular ( Fig. 4C ). Clypeus : Reticulate, moderately high, with 2+2+4 setae, all in anterior part (first pair just below the base of basal antennal article), without clypeal area or prelabral setae ( Fig. 5A ). Labrum : Mid-piece with 10 tubercle-like median; side pieces with 3+3 moderately longer and pointed lateral denticles ( Fig. 5A, B ). Mandible : Pectinate lamella with ca . 12–14 hyaline teeth, dentate lamellae undivided, with 6–8 teeth (usually eight) in one block ( Fig. 5C ). First maxillae : Coxosternite undivided, without coxosternal lappets and setae ( Fig. 5D ). Basal telopodital article ca . 2 times wider than long, with moderately long and thin lappets (approximately three times longer than wide; apically rounded), without setae. Distal article ca . 2.5 times longer than wide, distally rounded, with one ventral seta each. Coxal projection subtriangular, distally rounded, with 1+1 ventral setae on about half of the projection length. Second maxillae : Undivided coxosternite with 2+1 setae (arrangement as in Fig. 5D ), with concave anterior margin in median part. Telopodite poorly setose ( Fig. 5D, E ), with 1+1 setae on second maxillary articles 2, and with four long, sclerotized setae on distal articles (articles 3). Claws moderately elongated, about two quarters as long as terminal article, distally it gradually becomes slightly flattened, without spines or filaments ( Fig. 5E ). FIGURE 3. Schendyla antici sp. nov. : A–D , F . Paratype ♀ (IZB ChG0159), E . Paratype ♀ (IZB ChG0158). A . Antennae, ventral view. B . Terminal article of right antenna, ventral view. C . Forcipular segment, ventral view. D . Right walking legs of first two leg-bearing segments, ventral view. E . Penultimate sternite, ventral view. F . Anterior part of trunk, ventral view. Arrows point sensilla basiconica. Abbreviations : L : leg; S : sternite. Scale bars : 0.5 mm ( A , C ); 0.2 mm ( D–F ); 0.1 mm ( B ). FIGURE 4. Schendyla antici sp. nov. : A , B . Paratype ♂ (IZB ChG0153), C . Paratype ♀ (IZB ChG0159). A . Cephalic capsule and basal antennomeres, dorsal view. B . Forcipular segment, ventral view. C . Left forcipule, ventral view. Scale bars : 0.2 mm. FIGURE 5. Schendyla antici sp. nov. , paratype ♀ (IZB ChG0158). A . Clypeus and basal antennomeres, ventral view. B . Labrum, ventral view. C . Right mandible, ventral view. D . First and second maxillae, ventral view. E . Left second maxillae, ventral view. Scale bars : 0.2 mm ( A , D ); 0.1 mm ( B , C , E ). FIGURE 6. Schendyla antici sp. nov. : A , B , D , F . Paratype ♂ (IZB ChG0153), C . Paratype ♀ (IZB ChG0158), E . Paratype ♀ (IZB ChG0159). A . Ultimate leg-bearing segment and postpedal segments, dorsal view. B . Ultimate leg-bearing segment and postpedal segments, ventral view. C . Penultimate leg-bearing segment, ultimate leg-bearing segment and postpedal segments, ventral view. D . Distal part of right ultimate leg, ventral view. E . Distal part of right ultimate leg, ventral view. F . Penis, ventral view. Scale bars : 0.5 mm ( A–C ); 0.1 mm ( D–F ). Trunk : All sternites rectangular in shape, longer than wide ( Fig. 3E, F ). Pore-fields absent on all leg-bearing segments. Chaetotaxy uniform along whole body. Walking legs : Chaetotaxy similar throughout the entire body length. Distribution and relative size of setae as in Fig. 3D . Apical claws almost straight, distally pointed out and moderately curved, without accessory spines in the base. Ultimate leg-bearing segment : Ultimate pretergite with rectangular shape, laterally slightly rounded, wide as anterior margin of tergite of the ultimate leg-bearing segment, and with 7–8 relatively small setae arranged in a row closer to the posterior margin of pretergite; intercalary pleurites absent ( Fig. 6A ). Ultimate tergite inverted trapezoid, with anterior margin almost twice as long as posterior, and with slightly longer setae than on ultimate pretergite, arrangement as in Fig. 6A . Ventrally, ultimate presternite in both sexes with similar shape and setation as ultimate pretergite, somewhat wider than posterior margin of sternite of the ultimate leg-bearing segment ( Fig. 6B, C ). Ultimate sternite in both sexes inverted trapezoid, but with sharper corners and more expressed setation on the posterior half of sternite in males ( Fig. 6B ) than in females ( Fig. 6C ). Coxopleuron laterally rounded, each with two relatively large coxal pores opening on the surface separately, close to margin of sternite, partly covered or completely exposed, and with numerous small setae on the posterior half (more pronounced in males). Ultimate legs in both sexes inflated, composed of six articles, much longer than the penultimate ones and with noticeably wider articles; with somewhat proportionally longer setae in males. In both sexes, terminal articles ca . 3–3.5 times shorter than penultimate, with poorly visible rudimentary apical claw ( Fig. 6D, E ). Shape and chaetotaxy of the ultimate legs of both sexes are presented in Fig. 6B, C . Postpedal segments : Intermediate sternite only with few moderately long setae arranged along the slightly concave posterior margin ( Fig. 6B, C ). Intermediate pleurites absent in both sexes. First genital sternite approximately rectangular in shape, with concave anterior (somewhat more pronounced in males) and straight posterior margin, and with ca . 4–6 setae close to posterior margin in males or scattered more along the middle in females; second genital sternite with rounded posterior margin. Male gonopods biarticulate, with larger basal articles with ca . 2 or 3 relatively long setae positioned on posterior margin of articles, and rounded apical articles with three long setae distributed mostly on external sides of articles ( Fig. 6B, F ). Shape and setation of penis as in Fig. 6F . Female gonopods in a single lamina ( Fig. 6C ). Anal pores absent in both sexes ( Fig. 6B, C ). Intraspecific variation : Based on all specimens analyzed in this study ( type and non-type), the new species shows no intrasexual variability in the number of leg-bearing segments, fixed to 29 in males and 31 in females. All collected specimens are of a small size ( ca . 5–8 mm ), with a relatively similar coloration and setation, and with similar size and proportion of body parts (antennae, cephalic plate, forcipules, ultimate legs, etc.). When comparing the sexes, in addition to the differences in the number of leg-bearing segments and genital structures, it was observed that females are slightly larger than males (average size 6.5 mm vs 5.8 mm ). Also, the males have a more pronounced setation on the posterior half of the ultimate sternite and the coxopleura. There are no distinct differences between the sexes in the other morphological characteristics.