Osoriellus triangulatus Irmler 2014, n. sp.
Creators: name: Irmler, Ulrich
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Osoriellus
Osoriellus triangulatus

description: Osoriellus triangulatus n. sp.
(Figs 71 A-C, 98E)
Type material: Holotype, male: Venezuela: Prov. Falcón, Cogollal (68°49.64'W, 10°54.96'N), grazed grassland with logs, 19.3.1998, leg. C. Schmidt (UIC).
Diagnosis: Among the intermediate sized species between 4 and 5 mm, O. triangulatus is characterised by the strongly convergent pronotum. In this respect, it can be confused with O. tuxtlae. But in contrast to O. tuxtlae, the pronotum is still more convergent and the surface is matt due to the distinct microsculpture, whereas the pronotum of O. tuxtlae has no microsculpture and a polished surface.
Description: Length: 4.5 mm. Colouration: Dark brown; legs and antennae lighter brown.
Head: 0.63 mm long, 0.92 mm wide; eyes slightly prominent and slightly shorter than temples; sides of fore-head shortly convergent to obtuse anterior angles; front edge of clypeus even; clypeal angles produced to short granules; setiferous punctation coarse and dense; punctation on midline sparser; coriaceously punctate; close to eyes, punctures partly granulate; at base of antennae, small area impunctate; netlike microsculpture dense and deep except on impunctate area at base of antennae without microsculpture; surface of vertex matt.
Antennae slightly longer than head; second antennomere oval and slightly longer than conical third; antennomeres 4 to 6 as wide as preceding antennomeres, but quadrate; antennomeres 7 to 10 wider than preceding antennomeres and increasing in width; antennomere 7 approximately quadrate; antennomere 10 slightly wider than long.
Pronotum: 0.88 mm long, 0.92 mm wide; widest at obtusely rounded anterior angles; strongly convergent to posterior angles; close to posterior angles more strongly convergent than in anterior half; lateral margin fine; in posterior half slightly wider than in anterior half; in dorsal aspect, not visible close to anterior angles; setiferous punctation coarse; in irregular rows; narrow midline impunctate; wider at anterior edge than at posterior edge; within rows, interstices between punctures shorter than diameter of punctures; between rows, interstices between punctures at least as wide as diameter of punctures; between coarse punctures with sparse micro-punctation; netlike microsculpture weaker and wider than on head; surface slightly shiny.
Elytra: 1.08 mm long, 0.95 mm wide; with rows of setiferous punctures on deep coriaceous ground-sculpture; surface matt.
Abdomen with dense and coarse setiferous punctation except impunctate dorsal midline; microsculpture weak, but dense; surface matt.
Protibia: 0.55 mm long, 0.18 mm wide; 10 spines on outer edge; WLR: 2.8; in posterior aspect, comb at inner edge visible throughout its total length; posterior face with dense setation.
Aedeagus rectangularly angulate; apical lobe long; apex obtusely rounded.
Etymology: The specific name refers to the triangular shape of the pronotum.
description: 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 pages 289-290, DOI: 10.21248/contrib.entomol.64.2.231-354, http://zenodo.org/record/5461706