Amphichroum rotundatum Shavrin & Smetana, 2018

Shavrin, Alexey V. & Smetana, Aleš, 2018, New species of the genus Amphichroum Kraatz, 1857 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini) from China, Zootaxa 4508 (3), pp. 377-402 : 390-391

publication ID	https://doi.org/ 10.11646/zootaxa.4508.3.3
publication LSID	lsid:zoobank.org:pub:E53B4C53-554A-4913-8E3B-CE1C530DF004
DOI	https://doi.org/10.5281/zenodo.5962996
persistent identifier	https://treatment.plazi.org/id/DA218790-FFB0-2E29-248F-FD947A79FD14
treatment provided by	Plazi
scientific name	Amphichroum rotundatum Shavrin & Smetana
status	sp. nov.

Treatment

Amphichroum rotundatum Shavrin & Smetana View in CoL , sp.n.

( Figs. 17 View FIGURES 16–19 , 22–23 View FIGURES 20–23 , 41 View FIGURE 41 )

Paratypes: 1 ♂ [specimen dissected], 2 ♀: same data as the holotype (1 ♀: CS; 1 ♂, 1 ♀: NSMT) ; 1 ♂ [specimen dissected], 1 ♀ [specimen without antennae]: ‘ CHINA Sichuan, Gongga | Shan, Hailuogou , in front of | Glacier 1, 2800m 9.VII.96 | 29°35N 102°00E C58’ <rectangular label, printed>, ‘collected by | A. Smetana, J. Farkač | and P. Kabátek’ <rectangular label, printed> ( NSMT) ; 1 ♀: ‘ CHINA (W Sichuan) (14) | Daxue Shan, Hailuogou | Glacier Park ( Gongga | Shan ) tongue of glacier 1 | 3200m / 29.34N / 102.00E | 29.V.1997 [D.] Wrase’ <rectangular label, printed> ( CSC) GoogleMaps . All paratypes with red rectangular label ‘ PARATYPE | Amphichroum | rotundatum sp.n. | Shavrin A. & Smetana A. des. 2018’.

Description. Measurements (n=7): HW: 0.57–0.67; HL: 0.35–0.38; AL(holotype): 1.36; OL: 0.17–0.21; PL: 0.53–0.63; PW: 0.86–1.04; ESL: 1.07–1.32; EW: 1.13–1.46; AW: 0.92–1.44; MTbL(holotype): 0.72; MTrL(holotype): 0.58 (MTrL 1–4: 0.37; MTrL 5: 0.21); AedL: 0.75–0.82; TL: 2.81–3.75 (holotype: 3.05).

Head, pronotum and abdominal tergites reddish-brown; elytra yellow-brown to brown; antennomeres 3–11 or 4–11 and abdomen brown; mouthparts, antennomeres 1–2 or 1–3, lateral portions of pronotum and sometimes paratergites yellow (two paratypes paler, with yellowish body and yellow-brown tergites). Head with a pair of setose punctures on posterior portions of infraorbital ridges between ocelli and posterior margin of eyes; pronotum with moderately dense punctation, slightly larger and smoothed on lateral portions; punctation of elytra dense and deep, denser and coarser near scutellum; abdominal tergites without visible punctation.

Head 1.6–1.7 times as wide as long. Distance between ocelli slightly shorter than distance between ocellus and posterior margin of eye. Length × width of antennomeres (holotype): 1: 0.16 × 0.05; 2: 0.13 × 0.05; 3: 0.12 × 0.04; 4–5: 0.10 × 0.04; 6–7: 0.11 × 0.05; 8–9: 0.12 × 0.05; 10: 0.11 × 0.05; 11: 0.18 × 0.05.

Pronotum 1.6 times as wide as long, 1.5 times as wide as head, widest about middle, slightly more narrowed posteriad than anteriad; holotype and some paratypes with indistinct, wide longitudinal impression in middle part of pronotum; lateral portions distinctly flattened and slightly explanate.

Elytra wider than long, slightly or distinctly widened apicad, twice as long as pronotum.

Metatibia more than 1.2 times as long as metatarsus.

Male ( Fig. 17 View FIGURES 16–19 ). Protarsomeres 1–4 distinctly widened. Medial margin of protibia with two parallel rows of five to seven peg setae; mesotibia slightly curved mediad and slightly widened apicad, with dense row of seventeen to twenty short and wide thorns on medial margin, becoming slightly longer closer to apex. Apical margin of abdominal tergite VIII slightly emarginated. Apical margin of abdominal sternite VIII rounded. Aedeagus ( Fig. 22 View FIGURES 20–23 ) with median lobe gradually narrowed toward rounded apex; parameres significantly exceeding apex of median lobe, distinctly widened anteriad in lateral view, each with two pairs of apical and preapical short setae; internal sac long, with long rows of thorns in apical half and with wide field of strongly sclerotized thorns in basal portion Aedeagus laterally as in Fig. 23 View FIGURES 20–23 .

Female. Protarsomeres 1–4 narrow. Protibia and mesotibia without modifications; meso- and metatibia with long, strong thorns along entire length of outer margin. Abdominal tergite VIII and sternite VIII with small rounded apical margin.

Comparative notes. Based on the body size, shape of long parameres and on the presence of fields of large thorns in the internal sac, A. rotundatum sp.n. is similar to A. assingi sp.n. and A. tibetanum sp.n. Based on the shape of apex of the median lobe, it’s most similar to A. tibetanum sp.n., from which it differs by the darker coloration of the body, and denser and larger punctation of the head. From A. assingi sp.n. it differs by the anterior angles of the pronotum not protrudedanteriad. From both species it differs by the longer parameres and details of the internal sac.

Distribution. The new species is known from two localities ( Fig. 41 View FIGURE 41 ) in Daxue Shan and Gongga Shan ranges in Sichuan, China.

Bionomics. Specimens were collected at elevations from 2800 to 3850 m a.s.l. by sifting leaf litter and humus in crevices between large rocks in a broadleaved forest (C58) and leaflitter, moss and various debris under broadleaved shrubbery in a narrow gully with a tiny creek (C85).

Etymology. The specific epithet is a Latin adjective rotundatus, - a, - um (rounded). It refers to the rounded apex of the median lobe of the aedeagus.