The first record of the anopsobiid genus Shikokuobius Shinohara, 1982 in continental Asia, with the description of a new species from the Altais, southwestern Siberia, Russia (Chilopoda, Lithobiomorpha, Anopsobiidae)

Abstract A new lithobiomorph species, Shikokuobiusaltaicussp. n., is described from the Altai Mountains in southwestern Siberia, Russia. This is the first record of the genus Shikokuobius Shinohara, 1982 in continental Asia, all previous reports being from Japan. The distribution of Shikokuobius is mapped.

A collection of lithobiomorph centipedes from the Republic of Altai, Russia, deposited in the Zoological Museum of the Lomonosov Moscow State University, has yielded a single male of a new anopsobiid species of Shikokuobius. Four additional specimens of that new species have also been freshly collected from the Altai Province, Russia.

Material and methods
The material used in the present study was collected by S.I. Golovatch (Moscow, Russia) in the environs of Lake Teletskoye, Republic of Altai and by T.M. Krugova (Barnaul, Russia) with her team of volunteers in the Tigirek State Nature Reserve, Altai Province. Both sites are located in the Russian Altais, southwestern Siberia, Russia. Most of the material is currently deposited in the collection of the Zoological Museum of the Lomonosov Moscow State University, Moscow, Russia (ZMUM), partly also shared with the collection of the Perm State University, Perm, Russia (PSU).
The total body length was measured from the fore margin of the cephalic plate to the posterior end of the postpedal tergite. Leg length was measured excluding the length of the claw. Lengths are given as the minimum and maximum values. All measurements are given in millimeters (mm).
The mouthparts, legs and body segments of the new species were cleared in 10% KOH and mounted in permanent slides in sandarac medium (Krasheninnikov 2011) for examination. The specimens were examined and measured using a Meiji EMZ-5 stereo microscope, and stacks of colour images were manually generated using an Olympus OMD EM-10 digital camera with a Panasonic Lumix H-H025 25 mm f/1.7 lens mounted on a Zeiss microscope. Digital images were prepared using Photoshop CS6 image stacking software. The drawings were executed using a Zeiss microscope and a Zeiss drawing tube. The distribution map was composed using QGIS 3.0.
The terminology of the external anatomy follows Bonato et al. (2010).
The following abbreviations are used in the text: T, TT tergite, tergites; C, CC coxa, coxae; t trochanter; P prefemur; F femur. Name. The specific epithet refers to Altai, the locus typicus. Diagnosis. A Shikokuobius species with the body 4-6 mm long, the antennae composed of 15-17 antennomeres, commonly 15; coxosternal teeth large, separated from each other by distances less than width at the base of a tooth; P, F and T of 15 leg relatively short and thick, 15 C with a prominent, acute, mesodistal process; the number of coxal pores varying from 1 to 2 on 12-15 CC (formula 1,1,1,1 in the male and 1,1,1,2 in the female); 15 t and 15 P with bifurcate ventral spines (seldom on legs 13 and 14); at least each leg 15 with a bifurcate spine at the distodorsal end of P; 1-10 tibiae with a distal spinose projection (Figs 7-8, 24); 1-12 tarsi clearly unipartite, claws of 1-14 legs with two accessory spines, claw of legs 15 with a single accessory spine; 1 st female gonopodal segment with 2+2 coniform spurs and eight long setae, 2 nd with four setae, 3 rd with a single seta on the external face; terminal claw simple; male gonopod with four segments including terminal filament. Distribution (Fig. 46). Altai Province and Republic of Altai, southwestern Siberia, Russia.
Non-type material ♂. Length 4.9 mm, width 0.5 mm. All other characters as in holotype (Figs 39-40, 42), but antennae with 17+17 articles, first maxillae with at least six plumose bristles (Fig. 37); second maxillae with four plumose bristles; 14 C ventrally with a tiny denticle, as in Fig. 38; 15 P with a bifurcate spine at distodorsal end (Figs 41, 43); 15 leg with a single well-developed accessory spine; 3 rd gonopodal segment with two long setae on the external face.
Paratype ♀♀. All characters as in ♂♂. The number of antennomeres in females unknown: one ♀ with antennae completely broken off, while another ♀ with damaged antennae, having 12+7 antennal articles. Coxal pores as in holotype, formula 1,1,1,2 (Figs 34-35). The number of accessory spines unknown: both females had no 15 leg-pairs.  Gonopods without setae on internal face, with 2+2 conical spurs and simple claw (Fig.  27). All segments of gonopods with long setae (broken off as in Fig. 27): 1 st segment with eight setae, 2 nd with four ones, while 3 rd with a single seta on the external face of gonopod.

Remarks.
The new species belongs to the genus Shikokuobius Shinohara, 1982 that shows the following synapomorphies: antenna with up to 18 articles, 3+3 coxosternal teeth; spiracles on leg-bearing segments 3, 5, 8, 10, 12 and 14; coxal pores on 12-15 legs; 15 C with a prominent, acute, mesodistal process; 15 t and 15 P with spines, ventrally bifurcated at their tips; at least 15 P with a bifurcate spine at distodorsal end (as some specimens with spines apparently broken off, so these are not visible).
Finally, S. altaicus sp. n. is also rather similar to Ghilaroviella valiachmedovi Zalesskaja, 1975, from the Tajikistan in showing the same body length, simple and plumose bristles on the second maxillae; the number of antennomeres, 1-2 coxal pores, 2+2 spurs and a simple ♀ gonopodal claw. However, S. altaicus sp. n. is well-distinguished from the latter species by: (1) 3+3 coxosternal teeth (vs. 2+2 in G. valiachmedovi); (2) coxal process well-developed only on leg 15 (vs. on legs 14 and 15 in G. valiachmedovi) and (3) the absence of small warts at the base of the ♀ gonopodal claw (vs. 2 small warts in G. valiachmedovi). much obliged to A.A. Schileyko (Moscow, Russia) for the provision some of material from ZMUM and to T.M. Krugova (Barnaul, Russia) and her team of volunteers who collected fresh specimens of the new species and donated us their material for study. Special thanks are also addressed to reviewers, G.D. Edgecombe (London, UK) and M. Zapparoli (Viterbo, Italy), for very valuable comments and an SEM image. We are also grateful to I.H. Tuf (Olomouc, Czechia) who kindly shared some of old literature and corrected the draft.