Description. Head, thorax, elytra and abdomen dark, reddish-brown, antennae and legs black; head shining, with moderately large punctation and thin scattered setae, frons transverse; eyes large, strongly convex, roughly facetted; male antennae longer than body, surpassing elytral apices by 2 joints, in females a little longer than elytra; 1st antennal joint about as long as 4th, longer than 3rd and much shorter than 5th; prothorax elongated, about 1.34 times longer than basal width; strongly tuberculate at lateral middle; about as wide anteriorly as posteriorly; pronotum with sparse scattered fine punctation and a few erect setae; scutellum glabrous, triangular; elytra about parallel-sided, about 2.5 times longer, than humeral width; narrowed at middle and slightly widened posteriorly, with small very dense punctation and nearly indistinct recumbent pubescence, rounded apically; femora distinctly clavate; 1st abdominal segment about as long as all others together; body length of males: 7.5-8.5 mm, width at humeri of males: 2.0-2.3 mm; body length of females: 7.4-7.6 mm, width at humeri of females: 2.0-2.1 mm. Differential diagnosis. The new species is close to O. cantharinum (Linnaeus, 1767) (Figs. 3-4), but the body color is much darker; the elytra a little shorter, about 2.3-2,5 times longer than basal width (O. cantharinum - about 2.4-2.7 times); elytral punctation denser and rougher; the distance between upper eye lobes about 1.4 times more than width of the 1st antennal joint (in O. cantharinum - about 1.3 times); 5th joint about 1.5 times longer than 3rd (in O. cantharinum - about 1.3 times). Material. Holotype (♂): Mongolia [M 25], 22 km N of Buglan, 46°17′27.496″N, 091°34′39.778″E, 1600 m, 23-25.6.2025, L. Purchart leg. - collection of M.A. Lazarev (Moscow, Russia). Etymology. The taxon is named after Luboš Purchart (Department of Forest Ecology, Mendel University in Brno, Czech Republic), a specialist in Tenebrionidae.