taxonID	type	description	language	source
00DE5EF153B15290AEDC4BD1012614FD.taxon	description	Figs 5 G, H, 7 E – H, 8 I	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
00DE5EF153B15290AEDC4BD1012614FD.taxon	diagnosis	Diagnosis. BL = 2.09 mm (n = 1). Body densely setose and brown, finely punctate above; head rounded at base, vertexal foveae impressed, without vertexal horns or tubercles at base; frons narrowing and rising to common antennal base; eyes reduced, with two or three ommatidia; gular teeth well-developed; antennae with scape very long, slightly sinuate at base, antennomere II (pedicel) slightly longer than III – VI combined, globose, narrow at base, widening towards apex, convex along outer margin, slightly concave on inner, protruding slightly at apical internal corner, III – VIII all bead-like, V and VII slightly larger and bearing elongate setae, IX – XI forming loose club, IX and X bearing elongate setae, XI densely setose; pronotum slightly longer than wide, widest near front, sides rounded; pronotal disk with lateral and median subbasal foveae; disk with strongly marked lateral longitudinal impressions; elytra rather short (wingless), humeri evenly sloped, sides rounded, each elytron with sutural and lateral dorsobasal foveae, lateral fovea with strong impression running posterad ~ 2 / 3 elytron length; posterior margin of elytron with outer submarginal tooth; subhumeral fovea absent; dorsal surface of abdomen distinctly punctate; protibia swollen; junction of mesepimeron and metaventrite deeply foveate; metatrochanter with inner margin slightly expanded, with blunt tooth at inner corner; penultimate ventrite distinctly depressed at middle, swollen at sides, last abdominal ventrite bearing small median apical marginal flange. Aedeagus (Fig. 5 G, H) with rather reduced basal bulb, slightly rounded dorsally, with oval dorsobasal diaphragm; basal apodemes forming wide elongate plate; tegmen not obviously articulated with basal bulb, dorsally subdivided into two asymmetric processes, one shorter, thinner strongly arched, the other longer, wider, curved ventrally to acute apex; additionally, below tegmen, two thin, curved, spine-like processes, project apically and basally from midpoint of tegmen, distal process flattened at base.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
00DE5EF153B15290AEDC4BD1012614FD.taxon	distribution	Distribution. This species is known only from the Yasuní Biological Station in Amazonian Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
00DE5EF153B15290AEDC4BD1012614FD.taxon	etymology	Etymology. This species’ name refers to a mythical ‘ spirit of the jungle’, Amasanga, who came to the people in dreams and taught them to hunt	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
1C80667BA7EB59C3B427704DD50338B4.taxon	description	Figs 5 E, F, 7 A – D	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
1C80667BA7EB59C3B427704DD50338B4.taxon	diagnosis	Diagnosis. BL = 1.68 mm (4). Body densely setose, densely and finely punctate beneath; head rounded at base, vertexal foveae shallowly impressed, short vertexal tubercles present at base; frons narrowing and rising to common antennal base, with shallow median sulcus on surface; eyes (of male) strongly reduced, comprising short longitudinal series of two or three indistinct facets; gular teeth well-developed; antennae with scape very long, slightly sinuate, antennomere II (pedicel) slightly longer than II – V combined, in male slightly convex on outer margin, produced at inner apical corner, III – VIII all bead-like, but V and VII larger and bearing elongate setae, IX – XI forming loose club, X and XI slightly more closely associated than IX and X; pronotum elongate, ~ 1.25 × longer than wide, widest near front, sides rounded; pronotal disk with lateral and median subbasal foveae; disk with only weak lateral longitudinal impressions; elytra rather short (wingless), humeri evenly sloped, sides rounded, each elytron with sutural and lateral basal foveae, lateral fovea with strong impression running posterad ~ 1 / 3 elytron length; subhumeral fovea absent; protibia swollen; male metatrochanter with inner margin expanded, subquadrate, distal corner projecting perpendicularly as small, truncate tooth; last male abdominal ventrite weakly depressed, bearing small basal marginal tooth and larger median apical marginal flange; penultimate male ventrite not obviously modified. Aedeagus (Fig. 5 E, F) with subspherical basal bulb, bearing large, round dorsal diaphragm; basal apodemes paired, thin, slightly curved; tegmen short, widened from base to middle, sclerotized portion bent strongly ventrad into a hook with deeply divided, densely bristled lobes extending laterodistad; between them an unsclerotized, setose median lobe extends from tip.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
1C80667BA7EB59C3B427704DD50338B4.taxon	distribution	Distribution. This species is known from two localities in the foothills of the Andes, in western Pastaza Province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
1C80667BA7EB59C3B427704DD50338B4.taxon	etymology	Etymology. We name this species for the somewhat spider-like appearance, common to members of Bibrax, as a result of their geniculate antennae appearing to be an extra pair of legs.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F6DB8F00AF395D00BA52115553932086.taxon	description	Figs 2 G, H, 3 E – H	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F6DB8F00AF395D00BA52115553932086.taxon	diagnosis	Diagnosis. BL = 1.32 mm (n = 3). Eyes of both sexes with single facet, head subquadrate posteriorly, prolonged in front of eyes, deeply depressed at vertexal foveae, slightly elevated posteriorly; antennal base prolonged and narrowed anterad; antennal scape sinuate, narrowed to base and before apex, flagellomeres II – VI progressively shorter, VII slightly larger, VIII small, IX – XI forming weak, loose club; pronotum with lateral lobes rounded, median and lateral longitudinal pronotal sulci well developed; elytra very short (flightless in both sexes), together emarginate along posterior margin, each with single distinct, median basal fovea, with short longitudinal elytral sulci short extending posterad; male with visible abdominal ventrite 2 elevated at middle, elevation posteriorly concave, densely setose; male ventrites 3 and 4 simply depressed medially; other secondary sexual characters not evident. Aedeagus (Fig. 2 G, H) with large basal bulb with round dorsal diaphragm, bulb ventrally bearing strong basal shelf (which articulates internally with sternite 6); tegmen constricted at base, appearing articulated with basal bulb, bent strongly laterad, thence narrowing evenly distad, apex with very small spatulate tip.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F6DB8F00AF395D00BA52115553932086.taxon	distribution	Distribution. This species is known only from the cloud forests of the Yanayacu Biological Station, Napo province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F6DB8F00AF395D00BA52115553932086.taxon	etymology	Etymology. The name of this species refers to this abdominal modification, meaning in Latin ‘ plow-bearing’.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
86E21074F99F59998C2EC0991D6198FF.taxon	description	Figs 5 A, B, 6 A – D	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
86E21074F99F59998C2EC0991D6198FF.taxon	diagnosis	Diagnosis. BL = 1.10 mm (n = 2). Body identical in most respects to B. onorei, with the following exceptions: antennomeres II-IV slightly more slender, elongate, antennomere III, in particular, nearly as long antennomere II; median longitudinal pronotal sulcus more deeply impressed; male with only last two abdominal ventrites modified, penultimate with weak depression in distal third, weakly margined by transverse carina, last ventrite short, concave, with small slightly transverse apical marginal tooth. Aedeagus (Fig. 5 A, B) with basal bulb short, distal surface flat, bearing large oblique diaphragm on left dorsolateral surface; with pair of basal apodemes well separated, obliquely truncate with outer edge longer; tegmen trunk-like, basally cylindrical, extending distad from middle of apical surface of basal bulb, bent ventrad, flattening toward broad paddle-shaped apex; tegmen with short ventral tooth and shorter, weakly sclerotized lobe extending distad below apex of tegmen.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
86E21074F99F59998C2EC0991D6198FF.taxon	distribution	Distribution. This species is known from cloud forests of two localities at similar elevations on either side of the Rio Pastaza in Tungurahua province, Ecuador, both of them reserves managed by the EcoMinga Foundation.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
86E21074F99F59998C2EC0991D6198FF.taxon	etymology	Etymology. The name of this species refers to the popular Ecuadorian beverage, canelazo, made and enjoyed during Fiesta de Quito, an annual festival happening around the time of the discovery of this species (late November). The name also echoes the type locality Candelaria.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
309305BED1D556498EC334F52D49FBB4.taxon	description	Figs 2 K, L, 4 E – H	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
309305BED1D556498EC334F52D49FBB4.taxon	diagnosis	Diagnosis. BL = 1.89 mm (n = 3). Body with dense, matte-like pubescence; head with single large ommatidium on each side (in both sexes); vertexal foveae shallowly impressed; head rounded posteriorly, prolonged anteriorly into narrowly elongate antennal base; gular teeth well-developed; scape very elongate, weakly curved at base, male antennomere II (pedicel), slightly swollen, ~ 2 × as long as III, evenly widened to apex, antennomeres III – V ~ 1.5 × longer than wide, VI – VIII shorter, VII slightly wider than VI or VIII; IX – XI slightly larger, forming loose, weak club; pronotum elongate, ~ 1.5 × longer than wide, widest just anterior of midpoint, evenly narrowed to base and apex; lateral pronotal foveae deeply impressed, setose, joined by weak transverse sulcus that passes through smaller, nude median fovea, continuing laterad to weakly interrupt lateral margin; shallow longitudinal impressions extend anterad and posterad from lateral and median foveae forming weak sulci; elytra narrow at base (wingless), widening to apex, each with sutural and one lateral dorsobasal foveae, shallow sulci extending posterad from foveae; subhumeral fovea absent; wingless in both sexes; protibiae strongly swollen; male ventrite 5 with broad, shallowly concave, smooth median area, male ventrite 6 with minute median, apical tooth. Aedeagus (Fig. 2 K, L) with basal bulb large, irregularly subspherical, with prominent basal apodeme; diaphragm located dorsobasally; tegmen dorsoventrally flattened, widened from base as it curves dorsad and distad, apex split ~ 1 / 4 from tip, one side with serrate margin narrowing to acute point, other side slightly longer and ending in slightly expanded, blunt apical plate.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
309305BED1D556498EC334F52D49FBB4.taxon	distribution	Distribution. This species is known only from Ecuador’s coastal mountains just northwest of Guayaquil.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
309305BED1D556498EC334F52D49FBB4.taxon	etymology	Etymology. We name this species for the protected area in which it occurs, El Bosque Protector Cerro Blanco. Semi-surrounded by the greater Guayaquil metropolitan area, this oasis of biodiversity has exceptional conservation value.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E8A8F1D989E58C89F7E907D80309570.taxon	description	Figs 1 D – F, 2 C, D	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E8A8F1D989E58C89F7E907D80309570.taxon	diagnosis	Diagnosis. BL = 1.79 mm (n = 1). Body densely setose, densely and finely punctate beneath; head rounded at base, vertexal foveae shallowly impressed; frons elevated, elongate to common antennal base, with shallow median sulcus on surface; eyes (of male) well developed, convex, with> 20 fine facets; gular teeth well-developed; antennae with scape very long, slightly sinuate, antennomere II (pedicel) as long as III-VI combined, III – VIII all bead-like, but V and VII larger, IX – XI forming loose club; pronotum elongate, widest near front, with lateral and median subbasal foveae, as well as row of small secondary foveae along basal margin; disk with lateral and median longitudinal impressions; elytra moderately elongate (winged) with sides rounded, each elytron with sutural and lateral foveae, lateral fovea with strong impression running posterad ~ 1 / 2 elytron length; subhumeral fovea absent; protibia swollen, with modified inner marginal spurs; last abdominal ventrite slightly flattened, densely setose on each side. Aedeagus (Fig. 2 C, D) with large basal bulb bearing prominent basal flange where it articulates with sternite VI; tegmen articulated with basal bulb, tubular at base, strongly arched dorsad, then curved distad and flattening and narrowing to subacute apex.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E8A8F1D989E58C89F7E907D80309570.taxon	distribution	Distribution. This species is known only from the coastal forests of Esmeraldas, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E8A8F1D989E58C89F7E907D80309570.taxon	etymology	Etymology. The name of this species refers to the Chocó biodiversity hotspot, a biome largely limited to northwestern Ecuador and neighboring Colombia, where this species is found.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E7D8CFDB4D15B2CAB57E0731658DCC3.taxon	description	Figs 1 A – C, 2 A, B	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E7D8CFDB4D15B2CAB57E0731658DCC3.taxon	diagnosis	Diagnosis. BL = 1.89 mm (n = 1); body densely setose and brownish-orange; eyes prominent, borne on small prominence, comprising ~ 26 ommatidia; gular teeth well-developed, curved slightly dorsad; head rounded posteriorly, prolonged in front of eyes to prominent antennal base, vertexal foveae slightly impressed; frons finely punctate above; antennal scape thick and sinuate, slightly narrowed before apex (in lateral view), antennomere II (pedicel) swollen, approximately as long as III – V together, III – V similar in size, short, VI and VIII shorter, VII wider than long, IX – XI forming a club, IX and X transverse, X slightly wider than IX, X, and XI closely associated; pronotum rounded, widest anterad, with lateral lobes slightly produced; lateral longitudinal pronotal impressions very shallowly impressed; elytra longer than wide, slightly widened beyond midpoint, each with sutural and one lateral basal foveae, lateral with shallow longitudinal impression extending posteriorly ~ 2 / 3 elytron length; subhumeral fovea absent; flight wings present protibia swollen; metatrochanter not modified, metaventrite between second and third pair of legs with oblique carinae posterad a shallow median depression; last abdominal ventrite bearing small median apical marginal flange; third ventrite slightly flattened, posterior margin straight at middle. Aedeagus (Fig. 2 A, B) with basal bulb large, elongate oval, with blunt, apically knobbed pair of basal apodemes; diaphragm rather small, round, located just basad tegmen articulation; tegmen widened from base as it curves dorsad and distad, apex divided, with an elongate, sinuate subacute process extending beneath shorter, broad dorsal brush.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E7D8CFDB4D15B2CAB57E0731658DCC3.taxon	distribution	Distribution. This species is known only from the lower (~ 1500 m), southern slopes of the Volcán Sumaco, in the western Amazon, Napo Province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
2E7D8CFDB4D15B2CAB57E0731658DCC3.taxon	etymology	Etymology. The species is named after Chullachaki, a mythical ‘ one-footed’ spirit of the Amazonian jungle. He is purportedly able to change into any type of rainforest animal, guarding the forest against unwise uses.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B4E0DBE183275AF69739B85FDCAC0924.taxon	type_taxon	Type species. Bibrax bradleyi Fletcher, 1927, by original designation. Type locality. Barro Colorado Island, Panama.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B4E0DBE183275AF69739B85FDCAC0924.taxon	diagnosis	Diagnosis. Among Metopiasini, Bibrax has been diagnosed (e. g., by Asenjo et al. 2024; Mario Chaul and Lopes-Andrade 2024; Chandler, unpublished) by having a scape as long as the funicular antennomeres combined (unlike Rhinoscepsis), the abdomen laterally margined, with distinct paratergites (unlike Metopioxys and Metopiosoma), the second antennomere or pedicel (at least up until now) at least 2 × as long as the third, the lack of acute pronotal and vertexal tubercles (seen in Metopiellus), having distinct lateral and / or median longitudinal pronotal sulci, having abdominal sternite III (first visible) longer than the metacoxae, and having the anterolateral corners of the gula acutely projecting (the size of which are, in light of new species, quite varied). Secondary sexual characters, when present, frequently involve modifications of the male abdominal sternites, the male tibial apices, male antennal pedicel, and male trochanters. In some species the sexes are dimorphic in eye size, although in several species described below reduced eyes are present in both sexes. The male genitalia, while highly varied in particulars, are consistent in having a large basal bulb that is articulated with an elongate distal tegmen. Parameres are absent. Asenjo et al (2024) demonstrated the basal articulation of the basal bulb with an “ apodemal plate ” on the inner surface of sternite VIII, and all of the species have a variously developed process (sometimes paired) on the basal bulb for this purpose. The tegmen can be simple or quite elaborate, sometimes subdivided, and is highly diagnostic of each species.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
C4ACA30D22C05DC4B1D6FC5EE544C4D4.taxon	description	Fig. 8 F – H	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
C4ACA30D22C05DC4B1D6FC5EE544C4D4.taxon	diagnosis	Diagnosis. BL = 1.73 mm (n = 1). Body large, very densely setose; eyes (of female) with multiple facets, head rounded at sides, short anterior to eyes, with pair of lyriform carinae; gular teeth well-developed; antennal tubercle short, wider apically; antennal scape cylindrical, coarsely punctate, antennomeres II – V more slightly enlarged and more densely setose than VI – X; pronotum with anterior lobes weakly angulate laterally, median and lateral longitudinal sulci deeply impressed; elytra moderately long, not together emarginate along posterior margin; dorsal elytral sulci (from mid-basal foveae) distinct, reaching just beyond elytral midpoint; abdominal tergites densely setose; posterior corners of abdominal laterotergites rounded. Male. Unknown.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
C4ACA30D22C05DC4B1D6FC5EE544C4D4.taxon	distribution	Distribution. This species is known only from the higher elevations of the Bosque Integral Otonga, in northern Cotapaxi province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
C4ACA30D22C05DC4B1D6FC5EE544C4D4.taxon	etymology	Etymology. While appearing related to many of the smaller, flattened species described in this study, this species is considerably larger than most of them, leading to our naming it B. grandis.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F90D17D8E11352CBB86039883BA851B7.taxon	description	Figs 2 I, J, 4 A – D	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F90D17D8E11352CBB86039883BA851B7.taxon	diagnosis	Diagnosis. BL = 1.88 mm (n = 3). Body rather large, densely setose, reddish-orange; eyes of both sexes strongly reduced, borne on small prominence, comprising two or three indistinct ommatidia; head subquadrate posteriorly, prolonged in front of eyes to prominent antennal base, deeply depressed at vertexal foveae, slightly elevated posteriorly; antennal scape sinuate, narrowed to base and before apex, flagellomeres II – VI progressively shorter, VII slightly larger, VIII small, IX – XI forming weak, loose club; gular teeth not prominent; pronotum with lateral lobes strongly produced, rounded, pronotum strongly constricted posteriorly; median and lateral longitudinal pronotal impressions well developed; elytra rather short, with narrowed humeri (flightless), each with sutural and one lateral basal foveae, lateral fovea with short longitudinal impression extending posterad; abdominal paratergites wide; protibia swollen; male metaventrite with small flat glabrous area between and anterad metacoxae; male abdominal segment 5 markedly elongate, sternite especially, prolonged anterad into emarginate ventrite 4, deeply concave, with small, tubular denticle at basal margin; legs without obvious secondary sexual characters. Aedeagus (Fig. 2 I, J) with basal bulb large, basally truncate, dorsally angulate, with long basal apodeme; tegmen comprising two separate processes, a shorter, strongly arched and apically acute rod on left side; right-side process longer, terminating in dorsoventrally flattened, subrectangular plate.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F90D17D8E11352CBB86039883BA851B7.taxon	distribution	Distribution. This species is known only from the isolated Volcan Sumaco, in the western Amazonian basin, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
F90D17D8E11352CBB86039883BA851B7.taxon	etymology	Etymology. The name of this species refers to the uniquely elongate last abdominal ventrite.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
512A30269CAC5FE98BAB9DE0F3D2D47A.taxon	description	Figs 2 E, F, 3 A – D	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
512A30269CAC5FE98BAB9DE0F3D2D47A.taxon	diagnosis	Diagnosis. BL = 1.10 mm (n = 3). Eyes of both sexes with single facet, head subquadrate posteriorly, with transverse basal ridge on vertex, prolonged in front of eyes; antennal base prolonged and narrowed anterad, antennal insertions swollen; antennal scape sinuate, narrowed to base and before apex, antennomere II (pedicel) slightly swollen, ~ 1.5 × as long as III (Fig. 3 A – C), III conical, IV – VIII bead-like, alternating slightly in size (IV, VI, VIII smaller), IX – XI forming club, X and XI more closely associated than IX with X; gular processes evident but not large; pronotum with anterior lobes rounded (Fig. 3 A), strongly constricted posteriorly; lateral longitudinal sulci conspicuous; median pronotal sulcus weak; elytra very short, together emarginate along posterior margin; dorsal elytral sulci short and weakly developed; abdominal paratergites with posterior corners angulate; male with visible abdominal ventrites 2 – 4 depressed medially (Fig. 3 D); male lacking modification of mesotibial apex. Aedeagus (Fig. 2 E, F) with short, broad basal bulb, with oval dorsobasal diaphragm, diaphragmatic sclerite indistinct; short digitiform process extending from left, middle edge of basal bulb; slightly longer, narrow apically quadrate process extending from medioventral margin; longest process extending out of middle of basal bulb (articulated), a well sclerotized, basally bent, apically narrowed and slightly sinuate blade, terminating in blunt and weakly tufted apex; dorsally an articulated, weakly sclerotized process extends over basal two-thirds of median blade.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
512A30269CAC5FE98BAB9DE0F3D2D47A.taxon	distribution	Distribution. This species is known only from the higher elevations of the Bosque Integral Otonga, in northern Cotopaxi province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
512A30269CAC5FE98BAB9DE0F3D2D47A.taxon	etymology	Etymology. This species name honors Dr. Giovanni Onore, a pioneer of entomology in Ecuador, who facilitated the fieldwork and worked to protect the site that led to the discovery of this species.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B095B9DDDBB45AD58693B73FC6D8B2E1.taxon	description	Figs 5 C, D, 6 E – H	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B095B9DDDBB45AD58693B73FC6D8B2E1.taxon	diagnosis	Diagnosis. BL = 1.55 mm (n = 3). Body densely setose, brownish-orange; eyes of both sexes strongly reduced, borne on small prominences, comprising three or four indistinct ommatidia; head rounded posteriorly, prolonged in front of eyes to prominent antennal base, two deep depressions in lateral view: one in front of eyes and another one at vertexal fovea; antennal scape slightly sinuate, narrowed anterior to apex, antennomere II (pedicel) longer than antennomeres III – IV combined, III – VI progressively shorter, VII slightly larger, VIII small, IX and X similar sized, IX – XI forming club, antennomere XI rounded and slightly longer than antennomeres IX and X; gular teeth not prominent; pronotum with lateral lobes slightly produced, rounded, pronotum weakly constricted and gradually narrowed to base; median and lateral longitudinal pronotal impressions well developed; elytra rather short, with narrowed humeri, each with sutural and one lateral basal foveae, lateral fovea with broad longitudinal impression extending posterad; abdominal paratergites wide, projecting at posterior corners; penultimate male abdominal ventrite weakly depressed at middle with comb-like series of erect setae along apicolateral margins; last ventrite with similar setal comb less prominent. Aedeagus (Fig. 5 C, D) with basal bulb large and spherical, with pair of short, blunt basal apodemes; tegmen deeply divided into two separate processes of similar lengths, one sinuate, with concave apical margin, the other with spine-like end and curved dorsally.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B095B9DDDBB45AD58693B73FC6D8B2E1.taxon	distribution	Distribution. This species is known only from the lower (~ 1500 m), southern slopes of the Volcán Sumaco, in the western Amazon, Napo Province, Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
B095B9DDDBB45AD58693B73FC6D8B2E1.taxon	etymology	Etymology. We name this species for its males’ ‘ comb-bearing’ abdominal sternites.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
6C0A52DE851F54FCA7E1171010F196E4.taxon	description	Figs 5 I, J, 8 A – E	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
6C0A52DE851F54FCA7E1171010F196E4.taxon	diagnosis	Diagnosis. BL = 1.76 mm (n = 1). Body setose and reddish, finely punctate above; head rounded posteriorly, vertexal foveae slightly impressed; frons narrowing and rising to common antennal base; eyes reduced, with two or three ommatidia; gular teeth well-developed; scape elongate, weakly sinuate, antennomere II (pedicel) slightly longer than III – VI combined, narrow at base and widening towards distal end, with outer margin straight, inner apical angle protruding forming flattened, slightly translucent, rounded spatulate process, III-VIII bead-like, V and VII slightly longer and bearing elongate setae, antennomeres IX – XI forming loose club, IX and X slightly transverse and bearing elongate setae, XI densely setose; pronotum elongate, widest near front, sides rounded; pronotal disk with lateral and median subbasal foveae; disk with strongly marked lateral longitudinal impressions; elytra rather short (wingless), sides rounded, each elytron with sutural and lateral basal foveae, lateral fovea with strong impression running posterad; subhumeral fovea absent; outer posterior corner of each elytron with tooth; dorsal surface of abdomen largely impunctate; protibia swollen; metatrochanter with distal corner extended as strong spine; metafemora swollen, distinctly clavate; last abdominal ventrite bearing small median apical marginal flange; penultimate ventrite shorter, barely depressed at middle. Aedeagus (Fig. 5 I, J) with round basal diaphragm, short and irregularly subspherical basal bulb; basal apodemes conjoined, broad, flat, with prolonged apical corners; tegmen narrow and tubular at base, expanded distally, dorsally hooded, with strong, blunt ventral keel, two distal processes that are similar in length extend from ventral apex, one thinner, slightly sinuate and apically subacute, the other wider, with basal brush of setae along outer margin, apically bifid with sclerotized, acute tip and secondary, setose, unsclerotized apical lobe; expansive membranous internal sac surrounding much of tegmen apex.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
6C0A52DE851F54FCA7E1171010F196E4.taxon	distribution	Distribution. This species is known only from the Yasuní Biological Station in Amazonian Ecuador.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
6C0A52DE851F54FCA7E1171010F196E4.taxon	etymology	Etymology. This species is named for the Yasuní Biological Station, its type locality.	en	Tapuy-Avilés, Yarina, Díaz-Guevara, David R., Caterino, Michael S. (2025): First record of Bibrax Fletcher, 1927 (Coleoptera, Staphylinidae, Pselaphinae) from Ecuador, with descriptions of twelve new species. ZooKeys 1250: 105-133, DOI: 10.3897/zookeys.1250.156763
