The Neotropical species of the genus Osorius G - M, 1829 with remarks to the Neotropical Osoriid complex (Coleoptera: Staphylinidae: Osoriinae) Author Irmler, Ulrich text Beiträge Zur Entomologie = Contributions to Entomology 2010 2010-12-20 60 2 363 426 https://www.contributions-to-entomology.org/article/view/1782 journal article 10.21248/contrib.entomol.60.2.363-426 0005-805X 5212736 Osorius affinis SHARP , 1876: 385 (Figs 9 a-b) Type material examined: Brazil : Amazonas: São Paulo de Olivença , 1 female without further data ( holotype , BMNH ) . Diagnosis: O. affinis is one of the smallest Osorius species and, in this respect, similar to O. costaricensis . It can be distinguished from O. costaricensiscostaricensis by the large prominent eyes. It can be separated from O. boops that is also characterised by prominent eyes by the smaller size. Unfortunately, only the female holotype could be studied. The species was not found in any other collection. Description: Length: 7.0 mm. Colour: black, legs and antennae dark brown. Head :: 0.80 mm long, 1.25 mm wide; eyes slightly prominent and 0.5 times longer than temples; with moderately dense punctation; punctures denser near neck than on disc and clypeus; on average, distance between punctures as wide as or slightly smaller than diameter of punctures; surface with distinctly isodiametric microsculpture; slightly shiny; laterad with numerous supraocular striae and several supraocular granular setiferous punctures. AntennaeAntennae with 2 nd antennomere globular and 3 rd one conical; both antennomeres equal in length; antennomeres 4 to 11 increasing in width, but still penultimate antennomeres quadrate. Pronotum : 1.35 mm long, 1.45 mm wide; widest at anterior edge; continuously narrowed to posterior edge; shortly in front of posterior angles with weak emargination; lateral margin small, not visible at anterior angles in dorsal aspect, scarcely widened to posterior angles; disc with moderately dense longitudinal punctation; distance between punctures on average as wide as or distinctly smaller than diameter of punctures; a midline without punctures in posterior half; surface with deep isodiametric microsculpture, microsculpture deeper than on head, scarcely shiny. Elytra : 1.50 mm long, 1.45 mm wide; punctation deep and distinct; with deep coriaceous ground sculpture. Abdomen with fine and sparse punctation; punctation coarser and denser on VII; tergite each abdominal tergite with deep transverse depression at base. Front tibia with 8 spines, apical two inserting on long teeth.