Omalium tibetanum Shavrin, 2025, sp. nov.
Creators: name: Shavrin, Alexey V.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Omalium
Omalium tibetanum

description: 3.5.7. Omalium tibetanum sp. nov.
(Figs 47, 78, 85–87, 89)
Type material examined. Holotype ♂: CHINA: YUNNAN: ‘CHINA: N-Yunnan [C2005-03] | Diqing Tibet. Aut. Pref., | Zhongdian Co., 35 km | ESE Zhongdian, 3450 m | 27°41.00´N 100°01.47´E, devas- | tated mixed forest nr. small creek, | litter, moss, dead wood sifted, | 3.VI.2005, M. Schülke [C2005-3]’ <printed>, ‘Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <printed>, ‘HOLOTYPE | Omalium | tibetanum sp. nov. | Shavrin A.V. des. 2025’ <printed> (cSch).
Paratypes: CHINA: YUNNAN: 1 ♂ (dissected): same data as the holotype (cSh); 1 ♂ (dissected): ‘CHINA: N-Yunnan [C2005-09] | Diqing Tibet. Aut. Pref., | Deqin Co., Meili Xue Shan, | E-side, 14 km W Deqin, 2580 m,’ <printed>, ‘ 28°27.47´N 98°46.35´E, creek | valley below glacier, mixed forest, | leaf litter, moss, dead wood, sifted, | 11.VI.2005, M. Schülke [C2005-09]’ <printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <printed> (cSch). All paratypes with additional red printed label: ‘ PARATYPE | Omalium | tibetanum sp. nov. | Shavrin A.V. des. 2025’.
Description. Measurements (n=3): HW: 0.48–0.52; HL: 0.32–0.34; OL: 0.14–0.15; TL: 0.10; AL (holotype): 1.08; PL: 0.39–0.42; PWmax: 0.61–0.64; PWmin: 0.57–0.59; ESL: 0.79–0.88; EW: 0.83–0.94; MTbL (holotype): 0.45; MTrL (holotype): 0.23 (MTrL 1–4: 0.08; MTrL 5: 0.15); AW: 0.81–0.89; AedL: 0.50–0.52; BL: 2.87–3.20 (holotype).
Habitus as in Fig. 78. Body reddish-brown, with darker head and pronotum (lateral and basal portions of pronotum, abdominal paratergites and intersegmental abdomen markedly paler); antennomeres 6–11 brown; mouthparts, antennomeres 1–5 and legs yellowish. Punctation of head fine and dense, denser in middle and coarser on infraorbital portions; neck with fine sparse or dense punctation; punctation of pronotum dense, finer and sparser in middle and mediobasal portion; punctation of elytra about as that on pronotum, slightly finer and sparser in middle; abdominal tergites with fine and sparse punctation.Anterior portion with distinct transverse microsculpture; neck with fine isodiametric meshes; abdominal tergites with dense isodiametric microreticulation. Anterior and posterior margins of pronotum with row of short cuticular fringe.
Head 1.5 times as broad as long, with wide and deep anteriomedian depressions, reaching level of anterior margins of eyes; posteriolateral margins of clypeus reaching level of middle length of eyes. Latero-apical margin between anterior margin of eyes and clypeus with distinct small and moderately deep semicircular notch. Dorsal surface with diagonal longitudinal wrinkles between anterior margin of eyes and scutellum and on laterobasal portions of clypeus, with slightly elevated surface between punctures in middle and irregular longitudinal and diagonal wrinkles on infraorbital portions, denser and coarser on postocular parts. Anteocellar foveae deep and moderately narrow, convergent latero-apicad toward level of middle or anterior third of eyes. Temples 1.4–1.5 times as long as longitudinal length of eye, from posterior margin slightly narrowed posteriad toward widely rounded hind angles. Distance between ocelli 1.5–1.7 times as long as distance between ocellus and posterior margin of eye. Apical maxillary palpomere about three times as long as penultimate segment. Antenna with slightly transverse antennomeres 8–10; antennomere 3 about as long as and distinctly narrower than 2, 4 1.3 times as long as 3, 5 longer and slightly broader than 4, 6 slightly broader than 5, 7 slightly shorter and broader than 6, 8 broader than 7, 9–10 broader than 8.
Pronotum 1.5 times as broad as long, 1.2 times as broad as head, from widest anterior portion distinctly more narrowed posteriad than anteriad. Anterior margin slightly rounded, not protruded anteriad. Laterobasal portions not concaved in front of obtuse hind angles. Lateral portions moderately widely and deeply impressed, deeper in about middle. Surface of disc with two long and wide longitudinal depressions; mediobasal portion without (holotype) or with shallow oval depression; surface between all pronotal depressions slightly elevated, with indistinct and irregular longitudinal elevations between punctures.
Elytra twice as long as pronotum; hind margins straight. Dorsal surface of each elytron with strong irregular transverse and diagonal elevations between punctures (middle part of elytra of holotype without elevations).
Metatarsi about twice as long as metatibia.
Abdomen slightly narrower than elytra, with wide intersegmental membranes between abdominal tergites III– VI (holotype and one paratype).
Male. Posterior margin of abdominal tergite VIII truncate. Posterior margin of abdominal sternite VIII sinuate. Aedeagus with wide basal portion, gradually narrowed toward median lobe; median lobe from basal part gradually broadened toward middle, and from middle strongly narrowed posteriad toward small rounded apex; accessory plates moderately wide, relatively long, curved in apical portions, each with widely rounded apex; parameres reaching preapical part of median lobe, distinctly broadened in about middle, and from middle gradually narrowed apically toward narrow apical parts, each with two long apical and two moderately short preapical setae; internal sac long and moderately narrow, without sclerotized structures (Fig. 85). Lateral aspect of the aedeagus as in Fig. 86; apical portion of median lobe (lateral view) narrow, with slightly crenulate ventrolateral margin and slightly curved small apex, slightly curved laterodorsad (Fig. 87).
Female unknown.
Comparative notes. Based on the general shape of the body and the aedeagus, O. tibetanum sp. nov. is more similar to O. xizangense, described from Xizang (see below), but can be distinguished from it by the more rounded and less protruded anterior angles of the slightly more transverse pronotum widest in anterior portion (pronotum of O. xizangenese broader in the middle) and with slightly denser punctation, and by the shape of longer and narrower median lobe of the aedeagus.
Distribution. Omalium tibetanum sp. nov. is known from two localities in Zhongdian and Meili Xue Shan Mts., northern Yunnan, China (Fig. 47).
Etymology. The specific epithet is the latinized adjective derived from the area where the specimens were collected.
Bionomics. Specimens were collected from altitudes from 2580 to 3450 m a.s.l. by sifting of litter, moss and dead wood. One specimen was collected in Meili Xue Shan together with O. rutilum sp. nov. and O. sectum sp. nov. The photograph of the type locality in Zhongdian (C2005-3) as in Fig. 89.
description: Published as part of Shavrin, Alexey V., 2025, Review of the genus Omalium Gravenhorst, 1802 (Coleoptera: Staphylinidae: Omaliinae: Omaliini) of China, pp. 501-543 in Zootaxa 5588 (4) on pages 538-541, DOI: 10.11646/zootaxa.5588.4.1, http://zenodo.org/record/14896684