taxonID	type	description	language	source
039E879C8D14A77AFEB2FE9AFB4E8DB4.taxon	description	1. Median pronotal spines basally fused (Fig. 2, A), rarely separated (Fig. 2, B) [e. g. Mycetomoellerius agudensis (Kempf, 1967), M. holmgreni (Wheeler, 1925), M. isthmicus (Santschi, 1931), M. ixyodus, M. kempfi (Fowler, 1982), and M. relictus (Borgmeier, 1934)]. 2. Mandible dorsum smooth (Fig. 2, C), sometimes basally striated (Fig. 2, D), rarely completely striated (Fig. 2, E) [e. g. Mycetomoellerius iheringi (Emery, 1888)]. 3. Preocular carinae frequently well-developed (Fig. 2, C), never curved towards the frontal carinae. 4. Pilosity ranging from sparse (Fig. 2, G) to dense (Fig. 2, H). 5. Postocular protuberance generally conspicuous (Fig. 2, F). 6. Vertexal corners varying from rounded (Fig. 2, E) to angled / spiny (Fig. C, D, F). 7. Posterior margin of head generally with strong median impression (Fig. 2, F). 8. Postpetiole in lateral view without posteromedial impression (posterior margin rarely concave) (Fig. 2, H, K). 9. First gastral tergite often with conspicuous pairs of lateral and median ridges (Fig. 2, K). 10. Propodeal projections long in most species (Fig. 2, H). 11. Promesonotum usually with unequally-sized projections (Fig. 2, H) [some exeptions in M. atlanticus, M. farinosus (Emery, 1894), M. fiebrigi (Santschi, 1916), M. holmgreni, M. iheringi, M. oetkeri (Forel, 1908), M. pruinosus (Emery, 1906), M. tucumanus (Forel, 1914), M. turrifex (Wheeler, 1903), and M. zeteki (Weber, 1940)]. 12. Antennal scape sometimes with basal lobe (Fig. 2, C) [e. g. Mycetomoellerius cirratus, M. holmgreni, M. iheringi, M. kempfi, M. pruinosus, and M. tucumanus]; microtubercles generally present (Fig. 2, C, D, F).	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D14A77AFEB2FBE6FC688838.taxon	description	1. Median pronotal spines separated (Fig. 2, B), not basally fused (Fig. 2, A). 2. Mandible dorsally striated (Fig. 2, E), sometimes solely basally striated [e. g. P. levis (Weber, 1938)]. 3. Preocular carinae short, sometimes curved towards the frontal carinae (Fig. 2, B, E) [e. g. Paratrachymyrmex diversus (Mann, 1916), P. intermedius (Forel, 1909), and P. mandibularis (Weber, 1938)]. 4. Pilosity sparse (Fig. 2, G). 5. Postocular protuberance inconspicuous (Fig. 2, E). 6. Vertexal corners generally rounded (Fig. 2, E). 7. Posterior margin of head usually with strong median impression (Fig. 2, E). 8. Postpetiole in lateral view often with posteromedial impression (posterior margin concave) (Fig. 2, G, J). 9. First gastral tergite often with conspicuous pair of lateral ridges, median pair usually poorly-marked or absent (Fig. 2, J). 10. Propodeal projections short in most species [except in P. diversus, P. intermedius, and P. mandibularis]. 11. Promesonotum usually with subequal-sized projections (Fig. 2, G) [except in P. intermedius and P. mandibularis]. 12. Antennal scape never with basal lobe; microtubercles tiny (Fig. 2, B, E).	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D14A77BFEB2F912FC688F2C.taxon	description	1. Median pronotal spines separated (Fig. 2, B), if basally fused, then their apexes are considerably distant from each other [e. g. Trachymyrmex arizonensis (Wheeler, 1907)]. 2. Mandible dorsum striated (Fig. 2, E). 3. Preocular carinae short, frequently curved towards the frontal carinae (Fig. 2, B). 4. Pilosity sparse (Fig. 2, G). 5. Postocular protuberance inconspicuous (Fig. 2, B). 6. Vertexal corners slightly rounded (Fig. 2, E). 7. Posterior margin of head with mild median impression (Fig. 2, B). 8. Postpetiole in lateral view with posteromedial impression (posterior margin concave) (Fig. 2, G, I). 9. First gastral tergite generally with inconspicuous pairs of lateral and median ridges (Fig. 2, I). 10. Propodeal projections spiny (Fig. 2, G), rarely blunt [e. g. Trachymyrmex desertorum (Wheeler, 1911)]. 11. Promesonotum with subequal-sized projections (Fig. 2, G). 12. Antennal scape never with basal lobe; microtubercles tiny (Fig. 2, B, E).	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	description	(Figs. 3 – 7)	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	materials_examined	Type material. Holotype: BRA: MG, Viçosa, - 20.761430, - 42.862560, 2019 - 07 - 25, Amaro, G. (1 worker, ANTWEB 1047947) [CELC]. Paratypes: BRA: BA, Ilhéus, CEPEC - Herbário do Centro de Pesquisas do Cacau, - 14.790194, - 39.213208, 1986 - 10, Delabie, J. (1 worker, MZSPHYM 0136551) [MZUSP]. BRA: MG, Viçosa, Fundos Entomologia, - 20.758200, - 42.867617, 2019 - 07 - 25, de Souza, D. & Chaul, J. (1 dealate queen, UFVLABECOL- 005123, and five workers with the following codes: UFV-LABECOL- 005124, ANTWEB 1053547, ANTWEB 1047925, ANTWEB 1047924, and ANTWEB 1053546) [CELC]. BRA: MG, Viçosa, - 20.761430, - 42.862560, 2019 - 07 - 25, Amaro, G. (1 alate queen, ANTWEB 1047948, and 1 alate male, ANTWEB 1047950) [CELC]. BRA: MG, Viçosa, - 20.761430, - 42.862560, 2019 - 07 - 25, Amaro, G. (1 worker, UFV-LABECOL- 011016) [CELC]. BRA: MG, Viçosa, - 20.761430, - 42.862560, 2019 - 08 - 25, Amaro, G. (1 worker, UFV-LABECOL- 010956) [DZUP]. BRA: MG, Viçosa, Mata do Paraíso, - 20.805528, - 42.853417, 2016 - 07 - 12, Raimundo, A. P., Ferreira, L., Chaul, J. & Paolucci, L. (1 worker, ANTWEB 1047927) [JTLC]. BRA: MG, Viçosa, Mata do Paraíso, - 20.80395, - 42.85510, 2021 - 04 - 17, Figueiredo, G. & Chaul J. (1 worker, ANTWEB 1053564) [CASC]. BRA: MG, Viçosa, Mata São Geraldo SG, - 20.816667, - 42.916667, 2010 - 01, Audino, L. (Two workers with the following codes: ANTWEB 1047928, and ANTWEB 1047929) [ANTWEB 1047928 in CELC, and ANTWEB 1047929 in UFVB]. BRA: MG, Viçosa, Mata da Biologia, - 20.757517, - 42.865306, 2023 - 08 - 25, Figueiredo, G. & Santos, C. D. (Twelve workers in twelve pins with the following codes: ANTWEB 1047926, ANTWEB 1047946, ANTWEB 1047554, ANTWEB 1047555, ANTWEB 1047556, ANTWEB 1047557, ANTWEB 1047558, ANTWEB 1047559, ANTWEB 1047560, ANTWEB 1047561, ANTWEB 1047562, and ANTWEB 1047563) [all in CELC, except ANTWEB 1047946 which is in DZUP, ANTWEB 1047554 in CPDC, ANTWEB 1047555 in PSWC, ANTWEB 1047560 in INPA, and ANTWEB 1047561 in MZUSP]. Non-type material examined. VEN: Falcón, Serranía de San Luis, 11.215858, - 69.641154, 1993 - 08 - 18, Mayhé-Nunes, A. & Lattke, J. (Two workers, MZSPHYM 0136549) [MZUSP]. VEN: Falcón, Serranía de San Luis, 11.215858, - 69.641154, 1993 - 08 - 18, Mayhé-Nunes, A. & Lattke, J. (1 worker, MZSPHYM 0136550) [MZUSP]. VEN: Falcón, Serranía de San Luis, 11.215858, - 69.641154, 1993 - 08 - 18, Mayhé-Nunes, A. & Lattke, J. (Two workers, MZSPHYM 0136552) [MZUSP]. Worker measurements (holotype): HL 0.81, HW 0.88, HW 1 0.90, SL 0.70, PeL 0.13, An 3 L 0.06, MdL 0.58, MsL 1.21, PH 0.20, PL 0.34, PPH 0.27, PPL 0.25, HFL 1.13, G 1 L 0.95.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	description	Measurements in mm (10 paratypes measured): HL 0.71 – 0.89, HW 0.75 – 0.90, HW 1 0.83 – 0.93, SL 0.5 – 0.75, PeL 0.09 – 0.13, An 3 L 0.05 – 0.07, MdL 0.52 – 0.63, MsL 1.02 – 1.31, PH 0.17 – 0.22, PL 0.28 – 0.39, PPH 0.22 – 0.30, PPL 0.21 – 0.27, HFL 0.89 – 1.14, G 1 L 0.75 – 1.0.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	diagnosis	Diagnosis. Body pilosity dense, with long and flexuous hairs. Lateral pronotal spines well-developed; median pronotal spines inconspicuous. Mesonotum without well-defined projections; mesopleural surface without tubercles. Frontal lobes subtriangular, with a weakly crenulate anterolateral margin; frontal carinae extending to the vertexal margin. Postocular protuberance inconspicuous; preocular carinae developed, without projections on the vertexal margin. Rounded vertexal corners, vertexal margin with shallowly median emargination. Mandibles basally with oblique striations. First gastral tergite with tubercles linked laterally and forming a pair of longitudinal marginations, and some small crenate margins in dorsal region. Worker mildly bicolored, dark brown cephalic capsule and gaster, slightly lighter brown to ferruginous appendages, mesosoma, and metasoma. Worker description. Relatively small species for the genus standards; without strong polymorphism. Dense setae covering the body, larger setae on dorsum of head, small subdecumbent setae on antennomeres, mesosoma and metasoma flexuous, those on legs suberect. Integument dull; mildly bicolored: most of the body light brown to ferruginous, head and gaster dark brown. Head. Eye weakly convex, not fully surpassing head lateral margin. Mandibles shiny, except for oblique striation at base; masticatory margin with a total of nine teeth: a large apical tooth, an intermediate-sized subapical, followed by six, subequall and small teeth and a large basal tooth. Anterior clypeal margin with a median notch about as wide as the maximum scape width. Frontal lobes subtriangular, with mildly crenulate anterolateral margin; frontal carinae extending to the vertexal margin. Frons shallowly concave. Vertexal carinae parallel, poorly-defined. Preocular carinae reaching the vertexal margin, but not surpassing it as a projection in full-face view; postocular carinae inconspicuous, postocular protuberance tiny. Vertexal corners rounded, vertexal margin with shallowly median emargination. In profile view, posterior section of ventral margin of head with a feeble carinae, without protuberances. Antennal scape maximum width just posterior to midlength, with small piligerous tubercles, exceeding the vertexal margin by a little less than its maximum width when retracted; totaling eleven antennomeres. Mesosoma. Pronotal medial pair of spines absent or reduced, when present without fused bases; pronotum with a pair of well-developed anterolateral spines, sometimes with truncate tips. Mesonotum without projections, except for a few piligerous minute tubercles; mesopleural surface without tubercles. Metanotal suture shallow and wide. Propodeum dorsum bordered laterally by piligerous tubercles; pair of propodeal spines posterolaterally directed, slightly longer than the distance between their internal bases; propodeal spiracle projected from surrounding surface, posteriorly directed. Metasoma. In dorsal view, petiolar node subquadrate; postpetiole wider than long. Anterior subpetiolar and subpostpetiolar processes small. Petiolar node, postpetiole tergite and first gastral tergite unevenly covered with pilligerous tubercles; on first gastral tergite the tubercles are linked laterally and form a pair of longitudinal marginations, forming carinae, and some small tubercles forming interconnected carinae in dorsal region. Queen measurements (2 measured): HL 0.91 – 1.04, HW 0.92 – 1.17, HW 1 0.93 – 1.17, MoW 0.05 – 0.07, MoL 0.04 – 0.04, LoL 0.05 – 0.05, LoD 0.27 – 0.29, SL 0.63 – 0.68, PeL 0.11 – 0.13, An 3 L 0.08 – 0.10, MdL 0.71 – 0.72, MsL 1.49 – 1.72, MssctmW 0.82 – 0.95, MssctmL 0.70 – 0.82, MssctlL 0.26 – 0.33, MssctmL + MssctlL 1.10 – 1.28, PH 0.28 – 0.30, PL 0.41 – 0.53, PPH 0.37 – 0.44, PPL 0.28 – 0.28, HFL 1.32 – 1.38, G 1 L 1.42 – 1.62. Queen description. Similar to worker, except for the caste differences such as presence of ocelli, mesosoma with a well-developed mesonotum, and wings. Ocelli similar-sized. Pronotum with a pair of robust blunt anterolateral projections. In dorsal view, mesoscutum and mesoscutelum with abundant piligerous tubercles. Scutoscutellar suture broad and shallow; mesoscutellum posterior margin with a pair of robust projections. Propodeal spines with robust bases. Wings. Slightly infuscated; covered with microtrichia; forewing with eight closed cells (basal, costal + subcostal, discal 2 + 3, marginal 1 + 2, subbasal, subdiscal, submarginal 1, and submarginal 3 + 4); pterostigma slightly pigmented. Male measurements (1 measured): HL 0.61, HW 0.65, HW 1 0.73, EL 0.28, EW 0.20, IOD 0.48, OOD 0.22, MoW 0.05, MoL 0.04, LoL 0.06, LoD 0.23, SL 0.68, PeL 0.11, An 3 L 0.08, MdL 0.40, MsL 1.43, MssctmW 0.72, MssctmL 0.73, MssctlL 0.25, MssctmL + MssctlL 1.04, PH 0.18, PL 0.36, PPH 0.24, PPL 0.19, HFL 1.60, G 1 L 0.8. Male diagnosis. Frontal carinae extending beyond the posterior level of the eyes, reaching lateral ocelli. Preocular carinae well-developed, slightly converging apically and reaching the lateral ocelli. Lateral pronotal projections very short, with relatively wide bases. Propodeal projections short and blunt, twice as long as those of pronotum. Notauli narrow, strongly impressed anteriorly, and slightly posteriorly, forming a ‘ Y’; mesoscutellum as wide as long, with a pair of tiny blunt projections on the posterior edge. Mandible triangular; reticulate-punctate at basal half, apical half smooth; masticatory margin with six teeth, basal and apical larger than the others, with the remaining teeth unequally spaced. Anterior clypeal margin mildly bilobed. Pilosity dense, with ferruginous to dark brown setae all over the body, most strongly curved, but sometimes suberect. Penisvalva ventral margin with about 20 sharp, minute denticles; apex of valviceps round. Body dark brown, except for legs, mandibles, antennae and posterior portion of gaster (from abdominal segment V backward) which are light brown. Male description. Overall reticulate-punctate sculpturing. Pilosity dense, with ferruginous to dark brown setae all over the body, most strongly curved, but sometimes suberect. Head. Mandible triangular; reticulate-punctate at basal half, apical half smooth; masticatory margin with six teeth, basal and apical larger than the others, with the remaining teeth unequally spaced; basal margin fit tightly again anterior clypeal margin when mandible is closed; outer margin slightly sinuous. Anterior clypeal margin mildly bilobed. Frontal lobes subcircular and poorly developed, only partially covering the scape bulbus; frontal carinae extending beyond the posterior level of the eyes, touching lateral ocelli. Frons rugulose. Preocular carinae well-developed, curving slightly at apex touching the lateral ocelli. Antennal scape in rest position exceeding the posterior margin of the head by the length of antennomeres I and II combined, remaining twelve antennomeres slightly longer than wide, the last three being more robust than the others. Bulging eyes. Mesosoma. Lateral pronotal projections small, with a relatively wide base. Wide sulci between upper mesopleura and lower mesopleura, and between upper mesopleura and upper metapleura. Propodeal projections short and blunt, twice as long as those of pronotum. Notauli narrow, strongly impressed anteriorly, and slightly posteriorly, forming a ‘ Y’. Mesoscutum wider posteriorly than anteriorly, scutuscutellar sulcus broad and shallow. Mesoscutellum as wide as long, with a pair of tiny blunt projections on the posterior edge. Metasoma. Petiole, in dorsal view, subquadrate, with a pair of pointed projections posterolaterally. Postpetiole with a posteromedial shallow concavity. First tergum of the gaster longer than wide. Wings. Infuscated; covered with microtrichia; forewing with eight closed cells (basal, costal + subcostal, discal 2 + 3, marginal 1 + 2, subbasal, subdiscal, submarginal 1, and submarginal 3 + 4), with the medial (M) and cubital (Cu) veins less proeminent at apex; pterostigma slightly pigmented. Genitalia. Sternite IX distal margin round. Telomeres strongly curved internally, narrowing apically, with round apexes. Volsella digitus spatular (wider apically), mildly curved internally; cuspis forming a rounded lobe. Ventral margin of penisvalva with about 20 minute denticles; valviceps apex round. Geographic distribution. Brazil (Bahia, Minas Gerais, Rio de Janeiro, and São Paulo), Panama, and Venezuela.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	discussion	Comments. Mycetomoellerius janildae is similar to M. relictus, and some records of the latter could be of M. janildae. Mycetomoellerius relictus worker differs by the following characters: median pronotal spines present and not basally fused, vertexal margins angled, mesonotal projections blunt if present, abundant setae but that are shorter than those of M. janildae. Males of M. janildae and M. relictus are relatively similar, sharing the small lateral pronotal projections, narrow notauli, mesoscutellum with a pair of tiny blunt projections on the posterior edge, and propodeal spines short and blunt (Fig. 9). However, upon examining the genitalia differences can be observed, for example, the penisvalva of M. relictus has larger teeth on its ventral margin (Fig. 9, H), but smaller numbers than that of M. janildae (Fig. 9, G). Furthermore, a slight difference was observed in the shape of the apex of the penisvalva between the species, being more rounded in the case of M. janildae than in M. relictus. Despite these differences, both penisvalva follow a simple morphological pattern within Formicidae (Snodgrass, 1941), without major variations such as those observed in males of Apterostigma and Mycocepurus, which present notches and projections in certain regions of the penisvalva, in addition to a significant variation in the shape of its apex (Santos et al., 2024). Related to the volsella of males, a pattern common to species of the genus was observed, with the digitus internally curved and spatulate, with a slight difference in the cuspis lobe position.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	etymology	Etymology. Named in honor of Janilda Aparecida Assis dos Santos, the mother of the first author. The name is formed by the addition of the singular Latin genitive case suffix - ae to the first name of a female person; the orthography of an eponym is unchangeable and is not dependent on the generic name in which the epithet is applied.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D16A772FEB2F838FDBD8CB8.taxon	biology_ecology	Biology. The entrance to the underground nest is approximately 4 mm in diameter at the base and is situated at the bottom of a small mound of moist soil, measuring approximately 1.5 cm in height. A chamber was found at a depth of 15 – 20 cm, containing 12 workers and a small fungal garden, but no queens. Despite further excavation, no additional chambers were located, though deeper chambers may exist. Workers have been observed to transport frass and fragments of flowers, which are likely to be used to cultivate their symbiotic fungus. The fungus displayed a spongy texture and a yellowish hue.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	description	(Fig. 8)	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	materials_examined	Type material. Holotype worker: BRA: SP, Agudos, - 20.758332, - 42.864533, 1959 - 04 - 30, Kempf, W. (1 worker, MZSPHYM 0136545) [MZUSP]. Paratypes workers: BRA: SP, Agudos, - 20.758332, - 42.864533, 1959 - 04 - 30, Kempf, W. (Twelve workers with the following codes: MZSPHYM 0144990, MZSPHYM 0144991, MZSPHYM 0136543, MZSPHYM 0136544, MZSPHYM 0144992, MZSPHYM 0144993, MZSPHYM 0136545, MZSPHYM 0144994, MZSPHYM 0144995, MZSPHYM 0136546, MZSPHYM 0144996, and MZSPHYM 0144997) [all in MZUSP, except MZSPHYM 0144991 which is in DZUP]. BRA: SP, Luiz Antônio, Estação Ecológica Jataí, - 21.573941, - 47.734546, Rogerio & Adriana col. (1 worker, MZSPHYM 0136547) [CELC]. BRA: SP, Mogi Guaçu, Fazenda Caipirinha, - 22.226970, - 47.091813, Leal, I. R. (Two workers with the following codes: MZSPHYM 0136548 and MZSPHYM 0144998) [MZUSP]. Worker measurements (holotype): HL 0.93, HW 1.06, HW 1 1.09, MdL 0.72, SL 0.85, PeL 0.14, A 3 L 0.07, MsL 1.41, PH 0.25, PL 0.39, PpH 0.25, PpL 0.33, HfL 1.19, G 1 L 1.13.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	description	Measurements in mm (10 paratypes measured): HL 0.89 – 1.01, HW 0.93 – 1.10, HW 1 0.96 – 1.10, MdL 0.65 – 0.73, SL 0.7 – 0.95, PeL 0.12 – 0.15, An 3 L 0.05 – 0.08, MsL 1.27 – 1.48, PH 0.20 – 0.26, PL 0.35 – 0.46, PPH 0.23 – 0.32, PPL 0.29 – 0.33, HFL 1.19 – 1.36, G 1 L 0.85 – 1.2.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	diagnosis	Diagnosis. Body pilosity sparse, setae long and curved. Lateral pronotal spines well-developed; median pronotal spines well-developed, slightly basally fused. Mesonotum with two pairs of protuberances, anterior pair larger than posterior; mesopleural surface, apart from microtubercles, with one distinct digitiform protuberance anteroventrally directed. Frontal lobes subcircular, with crenulate margins; frontal carinae reach the vertexal margin. Postocular protuberance well-developed; preocular carinae extending to the vertexal margin. Vertexal corners angled, vertexal margin with distinct median emargination. Mandibles basally with oblique striations. First gastral tergite with linked tubercles, and a pair of lateral ridges. Worker description. Medium-sized to large species for the genus standards; without strong polymorphism. Setation sparse on body, slightly longer and curved on dorsum of mesosoma and metasoma, shorter on head, suberect on legs and scape, appressed in flagelomeres. Integument matte, mildly farinose; uniformly brown, with head only slightly darker and appendages slightly lighter. Head. Eye mildly convex, slightly surpassing head lateral border. Mandibles shiny, except for oblique striations at base; masticatory margin with a total of ten teeth: apical tooth large followed by nine smaller, subequally-sized teeth. Anterior clypeal margin with a median notch about as wide as the maximum scape width. Frontal lobes subcircular, with crenulate margins; frontal carinae reaching vertexal margin. Frons shallowly concave. Vertexal carinae oblique, well-defined, extending towards the occipital region of head. Preocular carinae surpassing the vertexal margin as a projection in full-face view; postocular carina poorly developed, postocular protuberance well-developed. Vertexal corners angled, vertexal margin with distinct median emargination. In profile view, posterior section of ventral margin of head with a developed carina which has protuberances. Antennal scape slightly exceeding the vertexal margin, its maximum width just posterior to midlength, with many well-developed tubercles; totaling eleven antennomeres. Mesosoma. Pronotal medial pair of spines well-developed, with slightly fused bases; pronotum with a pair of well-developed anterolateral spines, sometimes with truncate tips. Mesonotum with two pairs of protuberances, an anterior larger pair, and a posterior reduced pair; mesopleural surface with several microtubercles and one prolonged digitiform protuberance directed anteroventrally in the inferior region of lower mesopleuron. Metanotal suture shallow and wide. Propodeum dorsum with well-developed tubercles, without well-defined lateral borders; pair of propodeal spines posterolaterally directed, slightly longer than the distance between their internal bases; propodeal spiracle projected from surrounding surface, posteriorly directed. Metasoma. In dorsal view, petiolar node subquadrate; postpetiole wider than long. Subpetiolar process merely a bump, and subpostpetiolar process tiny and digitiform. Petiolar node, postpetiole tergite and first gastral tergite covered by randomly distributed pilligerous tubercles; on first gastral tergite the tubercles are linked laterally and form a pair of longitudinal marginations, forming carinae, and some small tubercles forming interconnected carinae in dorsal region. Queen and male. Unknown. Geographic distribution. Brazil (São Paulo).	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	discussion	Comments. The new species is distinguishable from the others in the genus by the lower mesopleuron projection, which, in other species such as M. janildae, is limited to just a small edge of the cuticle, or located on the upper mesopleuron (as in M. holmgreni). Mycetomoellerius mesopleuralis shows some resemblance to M. relictus and M. janildae for sharing with them the well-developed lateral pronotal spines. Short tubercles, a common feature of the genus, are much more developed and evident in M. mesopleuralis than in most other species, particularly on the antennal scapes and the first gastral tergite. The species is only known from three localities in the Atlantic forest domain.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
039E879C8D1CA770FEB2F8D4FC828E9C.taxon	etymology	Etymology. The specific epithet ‘ mesopleuralis ’ refers to the projection on the lower mesopleuron, with the Latin suffix ‘ - alis’ indicating relationship or belonging.	en	Santos, Carlos Daniel Assis Dos, Chaul, Júlio Cezar Mário, Serrão, José Eduardo (2025): Taxonomic contributions to Mycetomoellerius Solomon et al., 2019 (Hymenoptera: Formicidae: Myrmicinae): description of two new species and a key for the genus. Zootaxa 5569 (1): 93-118, DOI: 10.11646/zootaxa.5569.1.3, URL: https://doi.org/10.11646/zootaxa.5569.1.3
