Osoriellus tunariensis n. sp. (Figs 85 A-C, 102C) Type material: Holotype, male: Bolivia: Cochabamba, Villa Tunari, 800 m elevation, 17.10.1981, leg. M. Cooper (BMNH). Diagnosis: Both the total size and the shape of the pronotum of O. tunariensis are similar to O. argentinus. The species can be differentiated from the other species by the large prominent eyes and the contrast between the dense microsculpture of the head and the weak pronotal microsculpture. Description: Length: 5.6 mm. Colouration: Black; legs and antennae lighter brown. Head: 0.84 mm long, 1.26 mm wide; eyes prominent; distinctly longer than temples; sides of fore-head slightly emarginate to anterior angles of clypeus; anterior edge of clypeus even; setiferous punctation deep and dense; on vertex, partly coriaceously punctate; on central posterior vertex and at base of antennae impunctate; on supraocular area, punctures granulate; netlike microsculpture dense and deep; surface matt. Antennae lost. Pronotum: 1.14 mm long, 1.30 mm wide; widest at anterior angles; slightly convergent in even curve to shortly rounded posterior angles; lateral margin fine; finer at anterior angles than at posterior angles; anterior angles produced to very short acute teeth; setiferous punctation coarse and deep; impunctate midline widened from anterior margin to posterior margin; on average, interstices between punctures half as wide as diameter of punctures; microsculpture extremely weak; surface shiny. Elytra: 1.40 mm long, 1.36 mm wide; with dense and deep coriaceous ground-sculpture; setiferous punctures in irregular rows; surface matt. Abdomen with dense setiferous punctation; on tergites narrow midline impunctate; moderately weak netlike microsculpture; on impunctate midline weaker than on punctate area; surface of puntate area matt; midline shiny. Protibia: 0.70 mm long, 0.26 mm wide; 9 spines at outer edge; WLR: 1.4; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face very densely covered by yellow setae. Aedeagus rectangularly angulate; apical lobe thick; ending in obtuse apex; inner edge of apical lobe with numerous sensillae. Etymology: The specific name refers to the Bolivian village Villa Tunari, where the species was found.

Published as part of Irmler, Ulrich, 2014, The Neotropical species of the genus Osoriellus FAGEL, 1959 (Coleoptera: Staphylinidae: Osoriinae), pp. 231-354 in Beiträge Zur Entomologie = Contributions to Entomology 64 (2) on page 290, DOI: 10.21248/contrib.entomol.64.2.231-354, http://zenodo.org/record/5461706