taxonID	type	description	language	source
3D7287D8FFDCAD65FD89C225FD18A6BF.taxon	type_taxon	Type species	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDCAD65FD89C225FD18A6BF.taxon	diagnosis	Emended diagnosis Compound eye oval; scape wider than long; low occipital carina slightly crenulate. Mesoscutoscutellar sulcus crenulate. Fore wing venation with veins R 1, M + Cu, Sc + R, A and Cu fully pigmented; vein A connected to medial cell with vein cu-a; vein Rs closing marginal cell without bend. Metacoxa much enlarged, with dorsal surface rounded to angular, outer metacoxal surface posteriorly foveate, inner metacoxal surface almost entirely accommodated in anterolateral, shallow concavity of metasoma. Metatibia and metabasitarsus sometimes with ventral row of comb-like setae; two mesotibial and two metatibial spurs. Metasomal length variable.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	description	urn: lsid: zoobank. org: act: 5 B 2 A 60 D 5 - 012 F- 47 C 2 - 8 DE 0 - 6 D 0158 F 6110 C Fig. 2	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	diagnosis	Diagnosis Body comparatively slender (Fig. 2 A), metasoma longer than mesosoma (shorter in † M. chandrahrasa Brazidec et al., 2024 and † M. gungner sp. nov.). Head with transverse striae on frons (Fig. 2 B). Antennae longer than head + mesosoma combined. Median mesoscutal sulcus smooth (crenulate in † M. synchrotron Brazidec et al., 2024), axillae contiguous (not contiguous in † M. janzeni Bracidec et al., 2024 and † M. mjoelner sp. nov.). Hind coxa without carina and foveae along posterior margin (coxa carinate and foveate in † M. janzeni and † M. synchrotron). Ovipositor elongate, longer than body (Fig. 2 A).	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	etymology	Etymology The new species is named after Manuel Brazidec, the French palaeoentomologist who described † Megacoxa as well as a number of other extinct wasp taxa.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	materials_examined	Type material Holotype MYANMAR • ♀; Kachin State, Myitkyina District, Hukawng Valley; [26 ° 20 ′ N, 96 ° 36 ′ E]; unnamed horizon, mid-Cretaceous, upper Albian to lower Cenomanian, 98.79 ± 0.62 Ma (Cruickshank & Ko 2003; Shi et al. 2012); CNU-HYM-MA- 2016210.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	description	Description Female BODY. Length (except ovipositor) 3.7 mm, fore wing length 2.6 mm, ovipositor length 4.3 mm. Specimen complete, generally well preserved (left hind femur and tibia somewhat compressed), in clear amber piece with few and small air bubbles, no major occlusions obscuring specimen, anterior part of head covered with thin milky film. HEAD. Oval in lateral view, wider than long, eyes oval, occupy most of lateral surface of head (Fig. 2 B); ocelli situated on top of head in approx. equilateral triangle; frons with transverse, wavy striation; postocular carina absent; occipital carina well developed, smooth, slightly incurved dorsally, area around occipital foramen deeply concave; antennae slender, elongate, longer than combined length of head + mesosoma, scapus short, expanded distally, short pedicellus inserted subapically on scapus, antennomeres 4 and 5 longest (Fig. 2 B), antennomeres gradually shortening until apical antennomere, which is approx. 2 × as long as penultimate antennomere; mandibles with three teeth each; short, slender palps observed. MESOSOMA. With elongate, extended propectus (Fig. 2 D); pronotum narrow medially, triangular laterally, with anterior thoracic spiracle in notch in lateral margin; fore femur slender, fore tibia slightly expanded distally, with elongate, curved calcar; mesoscutum strongly arched in lateral view, vertical anterior surface curves smoothly into horizontal surface; horizontal surface flat, level with mesoscutellum, not prominently sculptured; median mesoscutal sulcus distinct, apparently smooth, extends to transscutal articulation; axillae distinct, triangular, continuous medially, separated from mesoscutellum by curved foveate scutoscutellar sulcus (Fig. 2 C); mesoscutellum flat, smooth with small punctures, triangular posteriorly; mesopleuron smooth, with depression medially, mesopleuro-metapleural sulcus distinct, crenulate; mid femur slightly spindle-shaped, mid tibia slender, with two short apical spurs; hind coxa broad basally, cone-shaped, without carina or foveae along posterior margin; hind femur spindle-shaped, broadened in middle; hind tibia flattened, expanded distally, without fringe of setae, with two apical spurs of subequal length (Fig. 2 A), inner spur approx. to distal tibial width of tibia; hind basitarsus with short erect pegs on inner side, of approx. same length as remaining tarsomeres, tarsal claws simple, slender. WINGS. Fore wing hyaline with veins C, R 1, Sc + R, M + Cu, A, Rs + M, Rs, M and Cu fully pigmented; Rs + M aligned with M + Cu; medial cell wide distally, rectangular; Rs present between Rs + M and r-rs, closing first submarginal cell; marginal cell narrow, closed in straight line by Rs; hind wings mostly covered by fore wings, apparently with little venation developed. METASOMA. 1.12 × as long as mesosoma, slender, fusiform, without prominent sculpture or pilosity; metasomal segment 2 largest, metasoma widest there, sternum 2 with concavities for accommodating hind coxae; slender, slightly swollen cerci extend from tip of metasoma (Fig. 2 C); sternum 7 tapered apically, folded over medially along longitudinal axis; ovipositor extending posteriorly, elongate, length 1.16 × body length (Fig. 2 A), ovipositor proper and sheaths slender, tip of 2 nd valvula with 6 – 7 small dorsal teeth. Male Unknown.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFDDAD60FDCDC384FB28A27A.taxon	discussion	Remarks † Megacoxa brazideci sp. nov. can be most easily recognized by the transverse striae on the frons and the elongate antennae; the ovipositor is also longer than in most other species of the genus. The frontal sculpture might help facilitate eclosion from a pupal chamber in wood; many other wood-living wasps have prominent sculpture on the head or mesosoma for this purpose (Turrisi & Vilhelmsen 2010; Vilhelmsen & Turrisi 2011). The species resembles † M. mjoelner sp. nov. in having the median sulcus smooth and the hind coxa without carina and foveae posteriorly, but differs in having the axillae contiguous.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	description	urn: lsid: zoobank. org: act: 15 AEDADB- 4 F 15 - 4903 - A 7 C 3 - A 633 A 786 FEF 0 Fig. 3	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	diagnosis	Diagnosis Compact body, metasoma of approx. same length as mesosoma (Fig. 3 A – B). Antennae shorter than head + mesosoma. Median mesoscutal sulcus smooth, axillae contiguous. Hind coxa without carina and foveae along posterior margin (coxa carinate and foveate in † M. chandrahrasa). Hind femur and tibia swollen, tibial apical spurs very short, less than half max. tibial width (spurs longer than tibial width in † M. chandrahrasa), hind basitarsomere slightly shorter than remaining tarsomeres combined (much longer in † M. chandrahrasa). Ovipositor elongate, longer than body (Fig. 3 A; ovipositor shorter than body in † M. chandrahrasa).	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	etymology	Etymology The species epithet is after Gungner, the never-missing spear of Odin, king of the Norse gods. It refers to the long ovipositor of this species.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	materials_examined	Type material Holotype MYANMAR • ♀; Kachin State, Myitkyina District, Hukawng Valley; [26 ° 20 ′ N, 96 ° 36 ′ E]; unnamed horizon, mid-Cretaceous, upper Albian to lower Cenomanian, 98.79 ± 0.62 Ma (Cruickshank & Ko 2003; Shi et al. 2012); CNU-HYM-MA- 2016211.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	description	Description Female BODY. Length (except ovipositor) 5.1 mm, fore wing length 3.2 mm, ovipositor length 6.9 mm. Specimen complete, generally well preserved in clear piece of amber with moderate amount of grit, no major occlusions around specimen but several diffraction planes, particularly in lower part of specimen; lower part of head obscured by frothy mass of bubbles with hair-like extensions. Small to minute air bubbles on surface of parts of specimen, especially around antennae, making observations difficult. Syninclusion: remains of spider exuvium. HEAD (Fig. 3 B). Held closely appressed to mesosoma, globular, without prominent sculpture or setation, eyes oval; ocelli situated on anterodorsal part of head in approx. equilateral triangle; postocular carina absent; occipital carina well developed, finely crenulate, slightly incurved dorsally; antennae shorter than head and mesosoma combined, basal antennomeres difficult to observe, distal antennomeres not much longer than wide except apical antennomere, approx. twice as long as wide and tapering; mouthparts difficult to observe, short palps observed. MESOSOMA. With propectus concealed; pronotum narrow medially, triangular laterally, with anterior thoracic spiracle in notch in upper lateral margin; fore femur spindle-shaped, thickened, fore tibia slender, slightly widening distally, calcar not observed; mesoscutum strongly arched in lateral view, vertical anterior surface curves smoothly into horizontal surface; horizontal surface flat, level with mesoscutellum, not prominently sculptured, with short, evenly spaced hairs; median mesoscutal sulcus distinct (Fig. 3 B), apparently smooth, extends to transscutal articulation; axillae narrow, continuous medially, separated from mesoscutellum by angled foveate scutoscutellar sulcus; mesoscutellum flat, smooth with small hairs, rounded posteriorly; mesopleuron smooth with small, evenly spaced hairs, with slight depression in middle, mesopleuro-metapleural sulcus straight, distinct, crenulate; mid femur thickened, spindle-shaped, mid tibia slender, slightly expanded distally, with two short apical spurs of approx. same length as distal tibial width; hind coxa broad basally, cone-shaped, without carina or foveae along posterior margin; hind femur very thickened, broadened in middle (Fig. 3 B); hind tibia very thickened, expanded distally, with dense mat of setae on inner side, two minute apical spurs of subequal length present, spur length less than half distal tibial width; hind basitarsus with short erect pegs on inner side, slightly shorter than remaining tarsomeres, tarsal claws simple, slender. WINGS. Fore wing (Fig. 3 C) hyaline with veins C, R 1, Sc + R, M + Cu, A, Rs + M, Rs, M and Cu fully pigmented; Rs + M aligned with M + Cu; medial cell wide distally, rectangular; Rs present between Rs + M and r-rs, closing first submarginal cell; marginal cell narrow, closed in straight line by Rs; hind wings covered by fore wings. METASOMA (Fig. 3 B). 1.09 × as long as mesosoma, compact, turnip-shaped, hardly separated from mesosoma, without prominent sculpture but with short, evenly spaced hairs; metasomal segment 2 largest, metasoma widest there; sternum 7 tapered apically, folded over medially along longitudinal axis; ovipositor (Fig. 3 A) extending posteriorly, elongate, length 1.35 × body length; ovipositor proper and sheaths slender, teeth on tip of 2 nd valvula not observed. Male Unknown.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD8AD6EFDC8C740FC13A30D.taxon	discussion	Remarks † Megacoxa gungner sp. nov. mostly resembles † M. chandrahrasa among the other species in the genus, but differs from the latter in having the hind coxa without prominent carina or foveae, the apical hind tibial spurs and hind barsitarsus shorter, and the ovipositor longer.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	description	urn: lsid: zoobank. org: act: 215840 BF-F 89 F- 4 A 1 B- 98 F 1 - A 738 E 89 B 3299 Fig. 4	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	diagnosis	Diagnosis Body comparatively slender (Fig. 4 A), metasoma longer than mesosoma (shorter in † M. chandrahrasa and † M. gungner sp. nov.). Antennae shorter than head + mesosoma (longer in † M. brazideci sp. nov.). Median mesoscutal sulcus smooth (crenulate in † M. synchrotron), axillae not contiguous (contiguous in † M. brazideci). Hind coxa without carina or foveae along posterior margin (coxa carinate and foveate in † M. janzeni and † M. synchrotron).	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	etymology	Etymology The new species takes its name after Mjølner (or Mjolnir), the magic hammer that was the chief weapon and primary attribute of Thor, the thunder god in Norse mythology. Like the ovipositor in † M. mjoelner sp. nov. (see below), the shaft of the hammer was shorter than it was originally supposed to be, due to the interference of the trickster god Loke in the form of a fly; he viciously stung the dwarven smith Brokk as Mjølner was being finalized, thus confirming the timeless malevolence of Diptera.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	materials_examined	Type material Holotype MYANMAR • ♀; Kachin State, Myitkyina District, Hukawng Valley; [26 ° 20 ′ N, 96 ° 36 ′ E]; unnamed horizon, mid-Cretaceous, upper Albian to lower Cenomanian, 98.79 ± 0.62 Ma (Cruickshank & Ko 2003; Shi et al. 2012); CNU-HYM-MA- 2016209.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	description	Description Female BODY. Length (except ovipositor) 4.3 mm, fore wing length 3.3 mm, ovipositor length 1 mm as preserved (Fig. 4 A), probably broken (see below). Specimen in mostly clear amber piece, with small midge (Diptera) syninclusion. Exudate covers lower part of head and a few diffraction planes extend from dorsal part of mesosoma. HEAD (Fig. 4 D). Globular, slightly wider than long, without prominent sculpture or setation; eyes oval, cover most of lateral surface of head; ocelli situated on top of head in approx. equilateral triangle; postocular carina absent; occipital carina well developed (Fig. 4 D), smooth, area around occipital foramen deeply concave; antenna clearly shorter than head + mesosoma combined, scapus curved, pedicellus short, antennomeres 3 – 13 cylindrical (Fig. 4 D), slightly longer than wide, decreasing in length distally, antennomere 14 approx. twice as long as wide, tapering distally; mouthparts difficult to observe, mandible apparently broad, teeth not visible; short palps can be observed. MESOSOMA. With elongate, extended propectus; pronotum narrow medially, triangular laterally, with anterior thoracic spiracle in notch in lateral margin (Fig. 4 C); fore femur spindle-shaped, fore tibia slightly expanded distally (Fig. 4 D), with elongate, curved calcar; mesoscutum strongly arched in lateral view, angled between vertical anterior surface and horizontal surface; horizontal surface flat, level with mesoscutellum, not prominently sculptured; median mesoscutal sulcus distinct (Fig. 4 B – C), smooth, extends to transscutal articulation; axillae distinct, triangular, not abutting medially, separated from mesoscutellum by oblique foveate scutoscutellar sulcus; mesoscutellum flat, smooth with small punctures, diamond-shaped; mesopleuron smooth, with depression medially, mesopleuro-metapleural sulcus distinct, crenulate (Fig. 4 C); mid femur spindle-shaped, mid tibia slender, with two short apical spurs; hind coxa broad, with carina along posterior margin but without foveae; hind femur spindle-shaped; hind tibia (Fig. 4 A) flattened, expanded distally, without fringe of setae, with two apical spurs of subequal length, inner spur shorter than distal tibial width; hind basitarsus slightly longer than remaining tarsomeres, tarsal claws simple, slender. WINGS. Fore wing (Fig. 4 B) hyaline with veins C, R 1, Sc + R, M + Cu, A, Rs + M, Rs, M and Cu fully pigmented; Rs + M aligned with M + Cu; medial cell wide distally; Rs present between Rs + M and r-rs, closing first submarginal cell; marginal cell narrow, closed in straight line by Rs; hind wing could not be observed. METASOMA (Fig. 4 A). 1.27 × as long as mesosoma, slender, fusiform, without prominent sculpture or pilosity; metasomal segment 2 largest, metasoma widest there; sternum 7 tapered apically, folded over medially along longitudinal axis; ovipositor (Fig. 4 A) bent ventrally, apparently broken, 1 st and 2 nd valvulae separated at tip and no teeth observed on tip of 2 nd valvula. Male Unknown.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD6AD6CFDCDC6CBFC0EA4AA.taxon	discussion	Remarks † Megacoxa mjoelner sp. nov. mostly resembles † M. brazideci sp. nov., from which it differs in having a smooth frons, shorter antennae and the axillae not being contiguous.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD4AD6AFDADC070FC56A75E.taxon	description	Fig. 5	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD4AD6AFDADC070FC56A75E.taxon	diagnosis	Diagnosis See Brazidec et al. (2024).	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD4AD6AFDADC070FC56A75E.taxon	materials_examined	Material examined MYANMAR • ♀; Kachin State, Myitkyina District, Hukawng Valley; [26 ° 20 ′ N, 96 ° 36 ′ E]; unnamed horizon, mid-Cretaceous, upper Albian to lower Cenomanian, 98.79 ± 0.62 Ma (Cruickshank & Ko 2003; Shi et al. 2012); CNU-HYM-MA- 2016208.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD4AD6AFDADC070FC56A75E.taxon	description	Description Female BODY. Length (except ovipositor) 5.4 mm, fore wing length 3.4 mm. Specimen in slightly gritty amber piece together with small beetle (Coleoptera) and midge (Diptera); wasp well preserved except for right foreleg cut off at base of tibia and ovipositor (Fig. 5 A) cut off approx. 0.5 mm from tip of abdomen. HEAD. Wider than long, head capsule without prominent sculpture or setation; eyes oval (Fig. 5 B), higher than long, without postocular carina; antennal insertions in depressions, frons overhangs them above; occipital carina well developed (Fig. 5 A), crenulate, area around occipital foramen deeply concave; clypeus short and wide, triangular with tip between antennal insertions; antenna (Fig. 5 B) slightly shorter than head + mesosoma combined, with short globular scapus and short flat pedicellus, antennomeres 3 – 14 flattened (probably an artefact), antennomeres 3 – 6 longer than 7 – 13, antennomere 14 approx. twice as long as wide, strongly tapered apically; labrum a small narrow flap below clypeus, concealed when mandibles are closed; mandibles broad, with three teeth (Fig. 5 B) each, apical tooth longest. MESOSOMA. With elongate, extended propectus (Fig. 5 A – B); pronotum narrow medially, triangular laterally; fore femur spindle-shaped, fore tibia slender, with elongate, curved calcar; mesoscutum strongly arched in lateral view, angled between vertical anterior surface and horizontal surface; horizontal surface flat, level with mesoscutellum, not prominently sculptured; median mesoscutal sulcus (Fig. 5 A) distinct, crenulate, extends to transscutal articulation; axillae distinct, triangular, abut medially, separated from mesoscutellum by oblique foveate scutoscutellar sulcus; mesoscutellum flat, smooth, pointed anteriorly, rounded posteriorly; mesosoma difficult to observe laterally because of position of legs and curvature of amber piece; mid femur spindle-shaped, mid tibia slender; hind leg much larger than fore and mid legs, hind femur strongly swollen, hind tibia (Fig. 5 C) strongly expanded distally, widest at approx. two-thirds from proximal end, with distinct fringe of setae distally on median ventral margin, two apical tibial spurs inserted just distally of fringe, inner spur longer than outer; hind basitarsomere approx. equal in length to remaining tarsomeres; tarsal claws slender, simple. WINGS. Fore wing (Fig. 5 D) hyaline with veins C, R 1, Sc + R, M + Cu, A, Rs + M, Rs, M and Cu fully pigmented; Rs + M aligned with M + Cu; medial cell wide distally; Rs present between Rs + M and r-rs, closing first submarginal cell; marginal cell narrow, closed in straight line by Rs; hind wing could not be observed. METASOMA. 1.68 × as long as mesosoma, fusiform, with weak sculpture and setation in ventral view; sternum 2 tapering anteriorly, broadening posteriorly to broadest point of metasoma, approx. twice as long as sternum 3; sternum 7 strongly tapered apically, folded over medially along longitudinal axis; base of ovipositor (Fig. 5 A) extends straight from dorsal part of metasomal tip and beyond tips of wings. Male See Brazidec et al. 2024.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
3D7287D8FFD4AD6AFDADC070FC56A75E.taxon	discussion	Remarks † Megacoxa synchrotron was described from a male and the holotype was deposited in Phyletisches Museum Jena, Germany (CASENT 0753237; Brazidec et al. 2024: figs 2 f, 8). The female we describe here resembles the holotype in a number of features: the antennal configuration, the crenulate median mesoscutal sulcus, the medially abutting axillae, the uniquely enlarged hind tibia (Fig. 5 C; Brazidec et al. 2024: fig. 8 a). The wing venation is virtually identical in the holotype and the present female (compare Fig. 5 D with fig. 2 f in Brazidec et al. 2024). The main difference between the two specimens is in their size, the female being almost twice as long as the holotype. However, such sexual dimorphism is not unusual in wood-living wasps (L. Vilhelmsen, pers. obs.). In most of the phylogenetic analyses (Fig. 1), the female specimen CNU-HYM-MA- 2016208 comes out in a polytomy with the three previously described species of † Megacoxa, including † M. synchrotron.	en	Vilhelmsen, Lars, Wu, Qiong, Wang, Zhen, Gao, Tai-Ping, Ren, Dong (2025): Three new species of the long-tailed wasp genus † Megacoxa Brazidec et al., 2024 (Hymenoptera: Megalyridae) from Kachin amber. European Journal of Taxonomy 976 (1): 238-254, DOI: 10.5852/ejt.2025.976.2793, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2793/12763
